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ASF MapReady User Manual - University of Alaska System

1. Save Incidence Angles v Interpolate Layover Shadow Regions li Save Layover Shadow Mask Save Clipped DEM The automatic mask takes a cut out height of 1 m and masks out every pixel below this threshold This function was designed for imagery near a coastline to mask out large water bodies that would otherwise make the terrain correction impossible Alternatively the mask can be user specified We have checked the Save Layover Shadow Mask option which means in addition to the terrain corrected product we will also get a matching file indicating which regions of the scene are in layover and shadow The Layover Shadow mask contains grayscale values as follows 1 Normal no layover or shadow 2 User Masked if a user mask or automatic masking was applied 3 Shadow 4 Layover 5 Invalid During export these grayscale values are converted to color values using a color look up table 52 ASF MapReady User Manual After the terrain correction all the distortions that are introduced by the side looking geometry of the sensor are removed 4 a og an rt BA at 4 os j Terrain corrected standard beam image of Cook Inlet 53 ASF MapReady User Manual In the next step the terrain corrected image can be geocoded as any other image Terrain corrected and geocoded image of Cook Inlet since we checked the Save Layover Shadow Mask option on the Terrain Correction tab this mask file ha
2. l I oO gt 3 lt i Ww Q Coherency matrix T3 e T11 magnitude l speckle filtered with l l refined Lee l l l l I l l l l l l l a J Geocoded coherency matrix gt T11 o w itude a magni z oc lt n amp B Polarimetric results derived from geocoded T3 matrix The two alternative processing flows for polarimetric data Gens et al 2013 63 ASF MapReady User Manual In the first processing flow A polarimetric results are generated entirely within PoISARPro before these results are then geocoded and exported to GeoTIFF in MapReady For the second processing flow B the polarimetric matrix generated by PolISARPro is geocoded with MapReady before any further polarimetric processing is applied to the data All these polarimetric results are directly generated in map projected space Only the export to the more GIS friendly Geo TIFF format is done with MapReady at the end While processing flow A is feasible and leads to complementary results to processing flow B for geometric terrain correction and geocoding it cannot be applied for processing that involves radiometric terrain correction The radiometric correction requires backscatter values that are only available in processing flow B The radiometric terrain correction requires the calculation of a brightness scaling factor that needs to be applied before any
3. of ALOS datasets it is the filename minus identifying prefixes 81 ASF MapReady User Manual Basename Examples IMG 01 ALAV2A041552240 01B2G_U ALAV2A041552240 01B2G_U IMG 02 ALAV2A041552240 01B2G_U IMG 03 ALAV2A041552240 01B2G_U IMG 04 ALAV2A041552240 01B2G_U LED ALAV2A041552240 01B2G_U VOL ALAV2A041552240 01B2G_U TRL ALAV2A041552240 01B2G_U ALAV2A041552240 01B2G_U txt or workreport in place of the txt file R133776389G15003 D R133776389G1S003 R133776389G1S003 L 04Aug06_56103_01 sard 04Aug06_56103 01 04Aug06_ 56103 01 sarl DAT 01 001 LEA 01 001 TRA 01 001 Output file names are entirely up to you but they are also specified by basename only typically the same basename as the input file s asf_mapready will automatically append an identifying file name extension as appropriate i e img jpg cpx tif etcetera Other Parameters As illustrated in the example sequence above the next four parameters are basically switches indicating whether a particular processing step needs to be performed or not For example setting the import switch to zero assumes that all the data is already in the ASF internal format The final results are kept in ASF internal format if the export switch is set to zero The default values file is described in more detail in the next section Intermediate files are usually deleted but the user can set the flag to keep them The batch file only needs to be defined if you want to run the
4. s implementation of geometric terrain correction uses the forward geocoding approach This approach requires the remapping of the reference DEM into slant range SAR geometry With the DEM in slant range geometry a simulated SAR image is generated that can be used to improve the geolocation of the SAR image This is particularly useful for legacy data especially for Radarsat 1 and JERS 1 data that have known geolocation issues The geometric terrain correction left adjusts the position of ridge lines and valleys However the brightness of the slopes leaning towards the sensors is still too bright while the slopes facing away from the sensor are still too dark The radiometric terrain correction right adjusts the brightness of the geometrically terrain corrected image according to the slopes Radiometric terrain correction adjusts the brightness of the pixels with respect to the observation geometry defined by incidence angle as well as the slope and aspect of the local terrain It is very sensitive to the proper alignment of the DEM with the SAR image Any offsets between the SAR image and DEM result in the application of an inaccurate radiometric correction factor In order to determine the offsets in azimuth and range direction an FFT match is carried out between the real and simulated SAR images The accuracy of the matching mainly depends on two factors 1 The quality of the reference DEM in terms of resolution and geomorphologic detai
5. 5 39 Saving mage SUD SEIS ruisg NA EE R A TEE 71 54 TOODar BUNONS cyrn A N semeuesdeeeesato meee atainioce 74 So SINAN OVUM V ATV ON MOS spicata eer E setae ataarectadtaer aatacteemeise 75 6 The Projection Coordinate COnve rter cccccccccsscccceeceececesseeeesseseeseeeeesseeesaeeesaaes 79 7 Using MapReady from the command line asf_Mapready ccccececeeeeeeeeeeeeeees 80 AI Generating a COnnguration Messner 80 ASF MapReady User Manual Tie IDON eee E E E T E 86 7 3 E a EA EA EEA E AEE AA A TAEA AE EA EEA 87 Pa NIN CONCCUO Meee eE 87 TI COCO CNG a E E 89 LO EXD O M a eras S E 90 ht Derat VAISS ING eorne aA 91 70 MapReady senings ING tices te cetiee toate stent entered EA TEN 93 7 9 Running asf_mapready in batch mode ccceececseeeceeeeeeeeeeeeeeseeeeeeeeesaeeeeas 94 8 Overview of other command line tools of the MapReady Suite cccecseeeeeeees 95 adu Se Dando eeun EEEE 95 analyze VAW certane a 95 ST CAO Le A E A N E E A E A E E A 95 AST Caponea a Gudea a a eee eles 96 AS Ie OOM a T A ea 97 ASI OCOCOGS aa ait nae ase ea seen eee Pe eee eee aetna rae ee 98 SE IMPON ci e ina menaa seca aia Gnesi a E 98 ASE KIM OVETAY cos cost0se dee ces AE guste ciemaagucastasgedastarsedeabaccagearaicuaiczarcs esas 99 asl IMaDIeaGy 2iisanninnnanernanenne nie aii 99 IS FEO OO Ica ers catiansaetaciat aatouiot oncaeid E saseatbeaeeatnaeoueeae 99 SE OTC OM sweitan ced outa taeda nadseienlcedeuant
6. Single look complex SLC can be dealt with in various ways By default the data will be ingested as a two band image an amplitude band and a phase band Alternatively the data can be kept in its original format having a real and imaginary part by setting the complex SLC flag Unless the complex data is used for polarimetric processing the data can be safely multilooked setting the multilook SLC flag to 1 The power in ERS 2 data decreased over time The apply ers2 gain fix flag default value adjusts the brightness as a function of time 7 3 Polarimetry The polarimetric processing requires quad pol SLC data This part of the processing flow is currently only working ALOS Palsar data There are number of decompositions and classification supported Three common polarimetric decompositions supported by MapReady Setting the respective flags pauli sinclair and freeman durden will include them in the processing flow The Cloude Poitier classification can be run in two different ways The cloude pottier flag maps the results to eight classes whereas the extended cloude pottier flag results in sixteen classes Both classifications are based on entropy anisotropy and alpha values These can be stored as three separate bands using the entropy anisotropy alpha flag Atmospheric conditions that rotate the polarity of the SAR signal can be corrected using the Faraday correction In addition a farcorr threshold can be set that only corrects
7. TIFF Colormap tuk 256 elements Pixel Size 12 5 m For interferometric data sets relevant image and baseline parameters are provided if enough information was available at the time of the data ingest 19 ASF MapReady User Manual Stats Meta Stats Map Display GoTo Help The Stats tab shows basic image statistics Average 39 588 The values are not exact since the entire aa image s pixel values aren t used to calculate Y 2 631 X 23 354 the values instead a subset is used and the Statistics are calculated from that This is to speed up the loading of the image when the application starts Mote Statistics are estimated 0 077 Map Meta Stats Map Display GoTo Help Mapping of Pixel Values to Display Values Greyscale Red Ge Ei Mapping 39 555 Two 5Sigma Three Sigma C Min Max Truncate fi e no mapping Custom Range Min Max Ignored alues Ignore particular value Value Ignore range of values Min Max o The Map tab allows the user to adapt the visualization settings By default images are displayed with a Two Sigma mapping data within the range of two standard deviation around the mean value in order to remove statistical outliers before mapping the image into the visualization range The Three Sigma option is operating on the same principle just a wider range The Min Max option takes the entire value into account so
8. This is important since the metadata file information may no longer fully represent the data once the data has been exported i e if remapping 2 ASF MapReady User Manual occurs then the statistics section if it exists will not accurately represent the exported data but does accurately represent the data prior to remapping during export JPEG jpg The available output formats are listed on the left JPEG PNG PNG pnq PGM TIFF GeoTIFF are common graphic formats PoISARPro is a PaM pan Standard format for polarimetric data processed by the ESA TIFF tif sponsored software package Because the JPEG format has the GeoTIFF tif best compression capabilities of these formats it was selected as PolSAR Pro bin the default All the above mentioned formats require the scaling of the data from floating point to byte values The GeoTIFF is the most flexible choice It allows to user to preserve the full dynamic range by keeping the floating point values as well as including spatial reference map projection in TIFF tags and GeoKeys commonly recognized by popular GIS packages lf no quantitative analysis is required later the values can be safely converted to byte values by choosing to save the output in byte format together with choosing a method for rescaling the floating point values to byte values For the scaling of floating point to byte values a number of sampling methods are available They are listed on the right The
9. VV qreen 1s HV and blue is HHFVV In addition each channel will individually contrast expanded using a 2 Sigma remapping for improved visualization pauli 0 If you have guad pol data available HH HV VH and VV you can use the standard Sinclair decomposition to map the 4 bands to the R G and B channels in the output image In this decomposition red is VV green is HV VH 2 and blue is HH In addition each channel will individually contrast expanded using a 2 Sigma remapping for improved Visualization sinclair 0 If you have quad_pol SLC data available you can use the Cloude Pottier classification using entropy and alpha to map the 4 bands to the eight classes in one band in the output image 111 ASF MapReady User Manual cloude pottier 0 If you have quad_pol SLC data available you can use the extended Cloude Pottier classification using entropy alpha and anisotropy to map the 4 bands to the 16 classes in one band in the output image extended cloude pottier 0 If you have guad_pol SLC data available you can have the entropy anisotropy and alpha values the values used in the Cloude Pottier classification output in three separate bands This can be useful if you plan on doing your own classification or Simply wish to inspect the raw entropy anisotropy and or alpha data entropy anisotropy alpha 0 If you have guad pol SLC data available you can
10. added t CO Aes configuration Liles Teas Strictly used in combination of defining a project Running asf_mapready with the create option and the import flag Switched on will generate an Files section where you can define further parameters files 0 The import flag indicates whether the data needs to be run through T ast import 1L for running it 0 for leaving out the import step For example setting the import switch to zero assumes that all the data 1s already in the ASF internal format Running asf_mapready with the create option and the import flag Switched on will generate an Import section where you can define further parameters import 1 If you wish to run an external program on the data after import you can set this flag to 1 and then specify the command in 107 ASF MapReady User Manual the External section external 0 The polarimetry flag indicates whether tasks relating to polarimetry will be performed 1 to enable 0 to disable Polarimetric parameters decompositions or classifications can be applied Faraday rotation correction can also be applied to the imagery polarimetry 1 The terrain correction flag indicates whether the data needs be run t though Tast Lercecorr Cloror running itp 0 tor leaving Gut the Terrain correction step Running asf_mapready with the create option and the terrain correction flag switched on wi
11. and low alpha corresponds to single bounce scattering so areas of the image which are dark blue are dominated by single bounce scattering Similarly dark red pixels represent low entropy and high aloha meaning dominant double bounce scatterers The grey pixels indicate points for which no output pixels had that particular combination of entropy and alpha values There are nine different Zones in the image only eight of which are mathematically possible These are the eight classes in the Cloude Pottier decomposition If we number the zones from 1 9 as in the diagram we can describe each zone as follows 58 ASF MapReady User Manual Zone 1 Zone 2 Zone 4 Zone 5 Zone 6 Zone 7 Zone 8 Zone 9 Also available as in intermediate product is the entropy alpha histogram plot It is in the same entropy alpha plane as the classification map aloha on the vertical axis from O to 90 and entropy on the horizontal axis from O to 1 but shows a histogram of the values In this dataset most of the values were in Zone 5 vegetation scattering medium entropy Most of the entropy alpha histograms will look similar to this most pixels will have entropy aloha values near the Zone 5 6 boundary with a tail extending down into Zone 6 and into Zone 9 High Entropy Multiple Scattering High Entropy Vegetation Scattering Medium Entropy Multiple Scattering Medium Entropy Vegetation Scattering Medium
12. asf_mapready tool in batch mode This procedure is explained in a later section Filled in with the basic minimum the configuration file would look like this 82 ASF MapReady User Manual asf_mapready configuration file General input file R125419155G61S014 ancillary file output file R125419155G18014 default input dir default output dir project 0 files 0 import 1 external 0 polarimetry 0 terrain correction Cali bratvLon O geocoding 1 export 1 mosaic 0 default values intermediates 0 short configuration file l dump envi header 1 tmp dir oO Note that default values will be provided automatically when appropriate while other fields will be left blank This is normal Some default values don t make sense but actually act as flags to tell asf_mapready that they built in defaults should be used i e lat begin 99 00 specifies an invalid beginning latitude since latitudes can only range from 90 0 to 90 0 When asf_mapready sees this value it will assume the default range of 90 0 to 90 0 and will ignore the 99 00 If you do perhaps enter an invalid value that asf_mapready does not recognize then appropriate warnings or errors will be printed to the screen and written into the log file It is a good idea to pay attention to the output enough to spot warnings and errors as they occur The configuration file can be extended to include the necessary parameters by using asf
13. can be stored as a standard false color composite with the bands 4 3 and 2 The near infrared band 4 will characteristically highlight the imaged vegetation in red Standard False Color Composite FCC Finally the user can define other band combinations that are suitable for other types of investigations 45 ASF MapReady User Manual 3 5 2 Converting optical ALOS PRISM data into GeoTIFF format The PRISM instrument on ALOS satellite provides high resolution 2 5 m panchromatic imagery and used to provide land coverage and land use classification maps for monitoring regional environments For this example we have chosen georeferenced 1B2R imagery over Delta Junction Alaska Georeferenced images leave the user the choice of map projection for the geocoding For most remote sensing studies in Alaska the preferred map projection is the Albers Conic Equal Area projection PRISM image geocoded to Albers Conic Equal Area projection 46 ASF MapReady User Manual General Calibration External Polarimetry Teram Garection Geocode Export Map Projection Albers Conical Equal Area F alaska Latitude of Origin 50 000000 E Specify Height Central Meridian 154 000000 Avg Height sgh First Standard Parallel Specify Pixel Size Second Standard Parallel ae Pixel Sime meters Datum Resample Bilinear Ignore projection errors The geocoded image can now be used in any further analysis as the GeoTIFF for
14. contain small holes or regions of no data that appear as black specks or small blank spots The data that is missing in these spots will generally result in minor defects showing up in the final product If you so choose you can opt to Fill DEM holes with interpolated values to smoothly interpolate the terrain over the regions with missing data While this will prevent minor defects from occluding the terrain surrounding the DEM holes the trade off is that the terrain that exists within the holes is now a best estimate It is suggested if your DEM contains holes that you try the processing with the interpolation algorithm turned on and off then compare the results to help you decide which method results in least impact for your purposes 22 ASF MapReady User Manual The image in the top left is the original DEM holes clearly visible The DEM in the top right image shows the result of the hole filling interpolation algorithm The bottom two images show a terrain corrected image using this DEM without hole interpolation left and with DEM hole interpolation right lf a SAR image contains areas that are moving e g water bodies or glaciers the user can refine the procedure by applying a mask The automatic mask considers all values in the DEM below a threshold of one meter to be masked out or ignored during those geolocation correlation processing steps that may have trouble matching the DEM to ever changing water co
15. e g when running the same data sets through the processing flow with different map projection parameters The batch file merely contains the basenames only of all the data sets to be processed one basename per line as shown below R153253303G3S007 R153253303G4S013 94 ASF MapReady User Manual 8 Overview of other command line tools of the MapReady suite A number of other command line tools are included in the MapReady tool suite however each tool s functionality is generally available through the MapReady GUI or the asf_mapready command line tool All of the tools generally only work with ASF Internal format files as input except asf_import and as output except asf_export Each tool has a help option that can be used to give detailed usage information Here we provide a brief overview of each tool s functionality and how it fits into the overall tool suite adjust_bands The adjust_bands program allows users to combine remove or reorder bands in one or more source files analyze_yaw This program extracts yaw and Doppler information out of a list of leader files Leader_file Yaw Doppler_range Doppler_azimuth RIGILAS2209PA 00 Lely OLI LUC4 14557 2246 00 RilolasZ22T4Pas00l Ey Osi L004 S981646 1535 414 RIG OZA A PASO OL ebp Gali op SLA y esC1625 RiLOIASZZ 3 ZPaSU0LsIy OEL 2Zotsc40oy FLI sL RIGl4o2235P 4500 Li 0 008 B296sI96 682220 asf_calibrate The asf_calibrate tool applies the calibration
16. floating point format from to byte format The GeoTIFF supports byte as well as floating point data The byte conversion options are SIGMA MINMAX TRUNCATE or HISTOGRAM _EQUALIZE They scale the floating point values to byte values in various ways e SIGMA Determines the mean and standard deviation of an image calculates a two sigma i e standard deviations range around the mean value and then maps image values within this range to 0 to 255 Image values that map to below 0 using are set to 0 and image values that map to greater than 255 are set to 255 e MINMAX Determines the minimum and maximum values of the input image and linearly maps those values to the byte range of 0 to 255 e TRUNCATE Values less than 0 0 are mapped to 0 values greater than 255 0 are mapped to 255 and values in between have their fractional portions truncated i e 29 7 would become 29 exactly e HISTOGRAM _EQUALIZE Histogram equalization is designed to optimize viewing for humans It is a nonlinear contrast enhancement that expands low dynamic range regions over a broader range of values and at the same time compresses areas of higher dynamic range over a lesser range of values The 90 ASF MapReady User Manual remapping function is derived from the image histogram Histogram equalization is useful for bringing out detail in areas of the image that otherwise seem to lack detail due to flatness or sameness in the brightness v
17. in cases where you are trying to use refine_geolocation to improve the geolocation of an image but the co registration process of refine_geolocation fails to produce a good match and hence produces poor offsets or no offsets at all In this situation you could measure the offset manually and use shift_geolocation to apply the measured offset 103 ASF MapReady User Manual smooth This program performs pixel averaging using a square kernel of a specified size This kernel size needs to be odd so that each pixel s new value is a result of averaging pixels centered on the target sr2gr The sr2gr program remaps a slant range into ground range This isn t used directly by MapReady or asf_mapready to_sr The to_sr program converts an image to slant range It replaces the old gr2sr utility which only worked on ground range images to_sr can convert projected images to slant range as well This is used by terrain correction during the co registration process which is done in slant range trim The trim program cuts out a rectangular portion of an image where the edges of the rectangle are parallel to the edges of the original image It works on slant ground and projected images in the ASF Internal format This is used in ASF View by the Save Subset capability write_ppf The write _ppf program generates a parameter file for processing Radarsat 1 data with a Doppler ambiguity This functionality requires special p
18. look up tables look in the ASF Tools Share directory The available look up tables can be found in the following path lt path gt asf_tools share asf_tools mapready look_up_tables In this folder you will find files ending in lut and pal Only the pal files can be applied to PolSARpro files They originated from PolSARpro and are named according to the PolsSARpro classitiication Co which they apply NOTE This field is OPTIONAL and only applies if you are processing PolSARpro files If not then you may leave this field blank If it is blank then any PolSARpro data that is processed will remain non meaningfully greyscale Se OSE OSE SHE SE H H SE SE polsarpro colormap The image data type is only relevant for PolSARPro ingest It determines whether the input needs to be as a matrix or a file Current options POLARIMETRIC_SEGMENTATION POLARIMETRIC_DECOMPOSITION POLARIMETRIC_PARAMETERS and POLARIMETRIC_MATRIX Se SF OSE OSE image data type If the name of the metadata file is not deducible from the name given for the input file it can be specified here Currently only GAMMA data needs to do this for other types of data either the input file is the metadata or the metadata filename follows a standard naming convention If you have renamed your metadata file against the standard naming scheme for the data you should rename it back rather than using this option Se HHH HE SE metadata file 110 A
19. no values are excluded for the mapping of the values With the Truncate option no mapping is applied to the data The Custom Range option allows for user defined minimum and maximum values That way the feature in that particular value range can be enhanced The Ignore Values section of the tab deals with excluding certain values from the calculation of the statistics Ignoring particular value is most often used for setting a 76 ASF MapReady User Manual certain background value The Ignore range of values option helps to filter out a bigger value range e g the outliers at the upper value range of an image Display The Display tab contains a few image settings For multi band images such as quad pol Palsar data you have the option of combining the bands into a RGB image By default the first band is shown in grey scale but by selecting the Combine Bands into RGB radio button and selecting bands for each of the RGB channels a RGB composite image is displayed When viewing multi band ALOS images in CEOS format this multi band capability is not available multi band data spread across multiple files is not supported You must first import the data using asf_import the command line tool or MapReady The multilook checkbox is grayed out for images that are already multilooked No non multilooked image data types are supported in MapReady 1 0 The Apply a Look Up Meta Stats Map Display GoTo H
20. of each processing step other than export will be another set of data in ASF Internal Format Only export will change the file format to something else i e to a graphics file format for GIS and viewer software compatibility ASF Internal Format data is a set of two files one that contains metadata information about the data in the dataset and another that contains the data itself in binary format The files share the same name but have different file extensions The metadata file ends in meta and the data file ends in img SAR data in its detected form reflects the intensity or amplitude of the Sigma reflected backscatter In order to use SAR data in a quantitative fashion Beta it is advisable to radiometrically correct the data Gamma The radiometry default value for Power Select Radiometry Sigma 3 the data ingest Is amplitude i e the pixel values in the image are raw digital numbers Alternatively the intensity of the SAR image can be expressed by its power Certain applications prefer to use the power of an image rather than the amplitude As mentioned before for quantitative measurements the calibration parameters need to be applied Depending on the type of measurements the calibrated values sigma beta or gamma refer to the different projections as discussed in the background section The values are in power scale y Scale output to decibels dB Optionally the values can be converted from powe
21. polarimetric product is derived from the data Therefore the PoISARPro processing needs to start with a coherency matrix T3 whose elements have been previously radiometrically terrain corrected and geocoded MapReady will error out when the user tries to apply radiometric terrain correction to polarimetric processing results generated with processing flow A For the full flexibility in working with polarimetric data using the processing flow B is strongly suggested Polarimetric data can be stored in a number of ways While it is usually distributed as separate files one for each scattering element HH HV VH VV the subsequent polarimetric processing is simplified when the data is transformed into a different format PolISARPro works with two different domains The coherency matrix T3 is derived from the Pauli scattering vector k while the covariance matrix C3 is based on the lexicographic scattering vector Q Most often polarimetric data are stored as 73 matrix since the diagonal matrix elements allow a physical interpretation The 111 element respresents single bounce scattering the T22 element shows double bounce scattering and the 133 element indicates volume scattering A special case for the polarimetric processing is UAVSAR data The most useful formats are the multilooked data MLC and the terrain corrected ground range data GRD Both formats are provided in linear power scale in Gamma radiometry For the ingest of GRD data into
22. results in no change in pixel size during the geocoding process An average height can be defined for the image that is taken into account and adjusted for during the geocoding process The default height is set to 0 0 meters no height correction Furthermore a vertical datum can be defined for geocoded image WGS84 NAD27 and NAD83 comprise the list of supported datums In addition a Hughes reference spheroid may be specified for the datum parameter as well 89 ASF MapReady User Manual Three different resampling methods have been implemented as part of the geocoding NEAREST NEIGHBOR BILINEAR and BICUBIC The bilinear resampling method is the default After geocoding a fill value is required for the regions outside the geocoded image By default this value is 0 but may be set to a different value here In order to ensure the proper use of projection parameter files we have implemented a number of checks that verify whether the map projection parameters are reasonable for the area that is covered by the data For example applying a projection parameter file that is defined for South America for a data set that is covering Alaska would lead to huge distortions These checks can be overridden by setting the force option 7 6 Export The following format values are considered valid TIFF GEOTIFF JPEG PGM PNG POLSARPRO All formats with the exception of GeoTIFF require the scaling of the internal ASF usually 32 bit
23. standard decompositions such as the Pauli decomposition and the Sinclair decomposition used to visualize polarimetric data However a more detailed analysis requires an in depth knowledge of the underlying physics and the properties on the ground In this example we used a band combination that is very close to that of the Sinclair decomposition assuming that the cross polarized bands HV and VH are close to the same The water bodies in our example are predominantly blue as the HH polarization provides the highest return The fields in the upper part of the image show different signatures and give an indication why polarimetric data is superior for studying properties on the ground compared to single polarized images The combination of the two polarizations including their cross terms carries a wealth of information especially when the phase information is added to the interpretation The Sinclair decomposition is also supported with the polarimetry tab in MapReady here we are illustrating how one can use the User Defined RGB settings to create the same thing 49 ASF MapReady User Manual PALSAR RGB composite HH HV VV 50 ASF MapReady User Manual 3 5 4 Terrain correcting standard beam RADARSAT imagery The terrain correction of radar data is a standard procedure before the image can be combined with any other data in a GIS environment You can use SAR images without terrain correcting them but the geolocations of peaks val
24. that are directed towards the sensor The radiometric terrain correction adjusts the brightness of these slopes More information about sources format and processing of DEMs can be found in the How to guide Digital elevation models Most digital elevation models such as SRTM are geoid based They need to be geoid corrected so that they actually refer to ellipsoid before they can be used for terrain correction There is no way to tell from the data itself whether it is corrected or not so it is good practice for the user to verify this 21 ASF MapReady User Manual detail of the DEM before using The correction is applied by default in the GUI but can also be applied using the command line tool geoid adjust General Calibration External Polarimetry Terrain Correction Geocode eee DEM File Pe Browse Fill DEM holes with interpolated values Apply geoid correction C Refine Geolocation Only Apply Terrain Correction Apply a user mask Automatically Mask Mask from File Mask File Browse lf Perform co registration FFT Matching Also apply radiometric Terrain Correction Save Incidence Angles Z Interpolate Layover Shadow Regions Save Layover Shadow Mask Save Clipped DEM Once a DEM is defined in MapReady by default the geolocation of the input SAR image is refined by the DEM However the user has a number of DEM and terrain correction related options to choose from Some DEMs
25. the data for Faraday rotation when this threshold is exceeded 7 4 Terrain correction For the terrain correction portion of the processing a digital elevation model see also How to guide Digital elevation models is required If the SAR image and the reference DEM have different pixel spacing the resolution of terrain corrected SAR image needs to be adjusted This resampling can be left to the asf_mapready tool to determine by setting the pixel spacing to 99 0 in the configuration file This is the default setting Alternatively a user defined value can be set instead 87 ASF MapReady User Manual The digital elevation mode parameter defines the location of the reference DEM During the terrain correction process co registration of the DEM and SAR image is accomplished in SAR geometry In some cases when parts of the images are known to be moving or changing e g water glaciers etc this can confuse the co registration step and cause it to fail If you provide the terrain correction step with a mask file that defines areas of the image to ignore i e the water or glacial regions then the co registration step has a far higher likelinood of success Instead of creating a mask manually see How to guide Generating a mask for terrain correction you may allow the terrain correction processing to automatically generate a mask for you by setting the auto mask water flag The automatically generated mask is based on the DEM an
26. the reference DEM pixel spacing 99 00 The heights of the reference DEM are used to correct the SAR image for terrain effects The quality and resolution of the reference DEM determines the guality of the resulting terrain corrected product digital elevation model In some case parts of the images are known to be moving e g water 112 ASF MapReady User Manual Glaciers etc This can cause severe problems in matching the SAR image with the simulated SAR image derived from the reference Providing a mask defines the areas that are stable and can be used for the matching process mask Instead of creating a mask you can have terrain correction automatically generate a mask for you based on the DEM which attempts to mask the regions of your scene that are water these regions provide a poor match Specifically all DEM values lt lim are masked unless a different height cutoff 1S specified with the water height cutoff option described next auto mask water 0 When creating a mask automatically with the previous flag you may specify use a value other than 1m as the height cutoff This value is ignored when auto mask water is 0 water height cutoff 1 000000 When applying a mask during terrain correction you can choose how the regions covered by the mask are filled in the final terrain corrected result You can either specify a non negative value of your choosing or if you d
27. use the Freeman Durden decomposition to map the 4 bands to the R G and B channels in the output image In this decomposition the red channel represents the amount of double bounce contribution the green channel represents the rough surface contribution and the blue channel represents the volume scatterer contribution freeman durden 0 Quad pol SLC data HH HV VH and VV bands in both phase amp amplitude must be available in order to use Faraday rotation correction This functionality corrects for atmospheric conditions that rotate the polarity of the SAR beam A 0 value indicates that the correction is turned off A value of 1 uses a single rotation angle for the entire image the single angle is the average of all the per pixel angles A value of 2 uses a local average of the per pixel angles faraday correction 0 If the Faraday Rotation angle is small you can elect to not apply the correction even if you have selected to above If the correction angle is smaller than the threshold angle then the correction is not applied Use I for no threshold which means the correction is always applied farcorr threshold 1 00 Terrain correction This parameter defines the output size of the terrain corrected image If set to 99 this parameter will be ignored and the asf_terrcorr will deal with the issues that might occur when using different pixel spacings in the SAR image and
28. 0 ASF MapReady User Manual Stop Processing sor TE The Stop Processing button interrupts the processing of the list of data sets The image that is currently being processed will stop with a Processing Stopped By User error though any data files that have already completed are left in the Completed Files section lt may take a moment for the processing to stop Help ig PT The Help button opens the PDF file of this manual 3 4 2 Tool tips All parts of the GUI i e buttons check boxes etc have tool tips attached to them They provide a brief explanation about the functionality and the options available to the user Export Format GeoTIFF tif gt Output data in byte format finstead of Floating paint With GeoTIFF images the output can be either Floating point or byte Floating point is more accurate however not all software understands ik 41 ASF MapReady User Manual 3 5 Examples In this section some of the most common uses of the MapReady tool are demonstrated 3 5 1 Converting optical ALOS AVNIR data into GeoTIFF format Band 3 E Band 4 The AVNIR instrument on the ALOS satellite is a four band visible and near infrared radiometer with a resolution of 10 m designed for observing land and coastal zones 42 ASF MapReady User Manual This multi band imagery is provided in CEOS format with four individual files for the respective bands and a common leader file By importi
29. 83 spheroid GRS1980 First standard parallel 60 Second standard parallel 65 Central meridian 154 Latitude of origin 50 False easting 0 False northing 0 The use of map projection parameters outside their regular value range is limited to avoid extreme distortions in the output image The following tests are performed to detect whether parameters are outside their regular range latitudes need to be larger than 90 degrees and smaller than 90 degrees longitudes need to be larger than 180 degrees and smaller than 180 degrees UTM zones are only defined between 1 and 60 UTM zone needs to be covered in some part of the image Polar Stereographic coordinates are only well defined in polar regions hence limited to areas higher than 60 degrees latitude and lower than 60 degrees latitude e latitudes need to within 30 degrees of the latitude range defined by first and second parallel for Albers Equal Area Conic and Lambert Conformal Conic projection e datum selections that may result in large errors i e using a NAD 27 datum for a map projection in Africa would fail unless the Ignore projection errors check box is checked Even though these restrictions are highly recommended they can be overridden by selecting the Ignore projection errors option Doing so will change process terminating errors into warning messages instead and the requested processing will continue An average height can be specified for the ge
30. ASF MapReady User Manual Version 3 1 Alaska Satellite Facility Engineering Group ASF MapReady User Manual This page is intentionally blank ASF MapReady User Manual Table of Contents te MMTFOGUCTION sesncxdscvsie dae reor ee eei o oe e o eer renren 5 2a G 219 DA KO OUN a emer nen te ne nen E ner en ea ere 5 Zle Bch 180 482 eee ere eee ee tena RnR eee PERS RU MERCE EN ERE eR ENTREE on ene Ee ne Perea errr ese enent oe 5 Bee MAND LOMO Me genast sary 2ocguenotassenaatossianot RA 6 239 Terain Coreen iaeetidnit hatte scat cea ada ert rtcddnceade S 7 eae Map NOV GUO INS ee Se tees certs EEEE EEEE 12 it ONAN cree senses eae They eh EOE 12 2 6 AGOMMOUPAUOIN MEss EAA antares 13 27 Temporary GIRCCIONGS rsidsesinadivsussidanterssesvavssilndsveadauanseid usual waerawdaeeidiwaunddus 13 3 Using the MapReady Graphical User Interface ccccceeccsseeeeeeeeeeeeeeeeeeeeeeeseeees 14 P E oo 1 9 Rega en E nee nea eee ea eer Tae 14 gk Genea svauiosssansoravesgssncuennyeniseaaiaiseaeaioteipe AS 14 Sey ae Ore 11 6 f 1 0 9 nel Bc eee mene mee ne ere tn eerste Oe ee ee eee eee eee 16 R He US a MO aaa cetera E E EEEE E EE aeecantasencatee 17 Oe Ae Poanmely TaD errai a E E E E E E E 18 SO leo gt etal CONE ION Fa Daes 21 31O GEOCOdE TaD orenen indier i eneretten tenein 24 CON yeas EDON hole ere ree ere Sen ee mene ene ree tere Tee 27 SA MEUL IOS aso a a N 29 239 Completed Fie napsin nienssaneregenarasubedayensbada
31. Durden bands band 0 Amplitude HH band 1 Ps single bounce Freeman Durden blue band 2 Pd double bounce Freeman Durden red band 3 Pv volume scatterer Freeman Durden green 96 ASF MapReady User Manual asf_export The asf_export program converts an image in ASF Internal Format and converts it to the desired output format such as GeoTIFF or JPEG An important capability of asf_export not available through MapReady is the ability to apply a color look up table to grayscale data that is being exported to a color capable format The ut option applies a look up table to the image while exporting Some look up table files are in the look_up_tables subdirectory in the asf_tools share directory For the terrain correction mask there is a layover_mask ut defined that color codes the terrain correction mask for further analysis Layover mask of a terrain corrected image 97 ASF MapReady User Manual asf_geocode The program asf_geocode takes a map projected or more commonly an unprojected e g a ground range image and geocodes it i e maps it to a specified map projection such as UTM or Polar Stereographic The geocoding process works by first mapping the edges of the original image into the output coordinate system and from those finding the extents of the input image in the Output projection space Then each pixel in the output is reverse mapped to find its corresponding pixel in the input coordinate sys
32. ENVI The CSV format refers to comma separated value a text file that contains data values in columns suitable for loading in a spreadsheet If you are using this option you ll want the subset to be fairly small Directory and Filename Directory F datal Browse Filename E122590290G1U014_adi This is where the directory amp filename of the subset image is specified You may use the Browse button to select a different output directory By default the output filename is the same as the loaded image s filename with _aoi appended where aoi is an abbreviation for area of interest The extension of the file shouldn t be specified it will be determined by the selected format either img amp meta for ASF Internal or csv for CSV Data To Save Pixel values The Data To Save option species exactly what data should be l l i i Incidence Angle saved Pixel Values is the default which would just store the data as it is displayed Look Angle Slant Range A common trick used by users at ASF is to use this feature to Tine produce an incidence angle map of the entire image first select Deanie the entire image by clicking on the top left ctrl clicking on the bottom right clicking Save Subset and choosing the Incidence Scaled Pixel Values Angle option here Lat Lon Strict Boundary This option indicates whether only points within the selected polygon should actually be exported or if the en
33. Entropy Surface Scatterer Low Entropy Multiple Scatterers Low Entropy Dipole Scattering Low Entropy Surface Scatterer Zone 3 which would be below Zone 2 is nota feasible zone and so it is not listed 59 ASF MapReady User Manual 3 5 6 Correcting Palsar for Faraday Rotation In L band data the ionosphere is assumed to have considerable effects on the SAR imagery The anisotropy in the ionosphere due to charged particles in the presence of a persistent magnetic field causes the so called Faraday rotation The Faraday rotation needs to be corrected for in order to avoid range shifts internal image deformations range and azimuth blurring in SAR images It could cause azimuth streaking and phase error for SAR interferometry Palsar quad pol amplitude HH Faraday rotation For more information on Faraday rotation the user is referred to Meyer F J and Nicoll J B 2008 Prediction detection and correction of Faraday rotation in full polarimetric L band SAR data IEEE Transactions on Geoscience and Remote Sensing 46 10 3076 3086 60 ASF MapReady User Manual 3 5 7 Using Pauli decomposition with UAVSAR data UAVSAR PolSAR data are distributed in a variety of formats multilooked products MLC ground projected products GRD compressed Stokes matrices DAT and digital elevation models HGT The ground projected products are in geographic coordinate In this example the GRD product is used to generate a Pa
34. IMG 04 ALAV2A037283110 O1B2G_U Input data type level two data Output data type geocoded amplitude image LAput barnes U4 Processed 8480 of 8480 lines Import complete In this example we are just interested in band 4 of an ALOS AVNIR image and only import this particular band 106 ASF MapReady User Manual Appendix A Configuration File Example This is an example of a complete configuration with full descriptions of each individual parameter asf_mapready configuration file General This parameter looks for the basename of the input file input file This parameter looks for the basename of the ancillary file for PolSARpro or GAMMA ingest ancillary file This parameter looks for the basename of the output file output file Default directory to find files in If there is no directory in t the Input file value this dzurectory will be appended to It default input dir t Default directory to pul Liles any If there TS nO directory an the output file value this directory will be appended to it default output dir The project flag indicates whether a project needs to be defined The project allows the use of naming schemes for output files Running asf_mapready with the create option and the import flag Switched on will generate an Project section where you can define further parameters Se SF OSE H H project 0 The files flag indicates whether a file name list is to be
35. LOAT AirSAR UAVSAR VP JAXA LO ALOS mosaic TerraSAR X Radarsat 2 PolISARPro GAMMA ROI PAC SMAP ASF internal config file command line ENVI ENVI ESRI ESRI TIFF TIFF GeoTIFF GeoTIFF JPEG JPEG PNG regular Alpha GE PNG regular Alpha GE PGM PGM PolSARPro PolSARPro HDF5 HDF5 netCDF netCDF 117 ASF MapReady User Manual Import GUI input format multilook complex data default applies default look count range look count 1 ERS 2 gain correction color map for PoISARPro include precision state vectors add extra InSAR files define UAVSAR data type via settings file Polarimetry GUI Faraday rotation local global threshold Pauli decomposition Sinclair decomposition Cloude Pottier 8 16 categories entropy anisotropy alpha Freeman Durden config file input format apply calibration incl dB scaling multilook complex data keep complex data format set azimuth look count set range look count ERS 2 gain correction color map for PoISARPro look up table for range scaling latitude constraint for STF data define image data type for include precision state vectors add extra InSAR files define UAVSAR data type config file Faraday rotation local global threshold Pauli decomposition Sinclair decomposition Cloude Pottier 8 16 categories entropy anisotropy alpha Freeman Durden command line input format apply calibration incl dB scaling multilook comp
36. Mask so that file is Remove Queue For Reprocessing View Log view Intermediates A view Layover Shadow Mask view Entropy aloha Class Map available g __ The Clear button deletes the images from the completed files Clear Completed Files section ae E data alosiLED 4L4Ay24037283110 01826_U E datatalos4lLayv24037283110 01B26_LU tiF Kai Done ty A thumbnail for the each output image is generated once it is moved into the completed files section The information about input and output names remains available 39 ASF MapReady User Manual 3 4 Summary Section The user can find all file names and parameters that are used by the conversion tool in one compact list The list is divided into separate entries for each of the tabs The summary allows the user to verify which of the processing steps are selected and what input values are used for the Summary Import CEOS Level One Data type Amplitude Terrain Correction Yes DEM alaska _dem img Pixel Size 25 000000 m From geocode Interpolate Layover Yes Automatic Mask Save DEM amp Layover Mask Geocoding Albers Conical Equal Grea Center 50 000000 154 000000 Standard Parallels 55 000000 65 000000 Pixel Size 25 000000 m Datum VWisSe4 Resampling Method bilinear Export geaTIFF Byte Scaling Method Sigma individual processing steps It is updated each time make a change in the tab section of the GUI 3 4 1 Footer bu
37. P PAPH 3 1610000 0000000 Facility Related Data AVG TERRAIN HT oooo000 NG CTE LINE NUM 4096 000000 Image File Descriptor IMG CTR PIX NUM 4096 000000 IHMiAGE LENGTH Loz 4000000 TH4GE WIDTH loz 4000000 HUM SAE CHANNELS 1 HISSION ID ERS z SENSOR ID ERS 2 C OFEIT NUMBER SoS41 FLAT LAT NADIE B7 837 PLAT LONG NADIE 143 7595 PLAT HEADING 202 5929 SNSERE CLE ANGLE 30 000 INCIDENCE ANGLE fe_ 9fe RAaADAE FREQUENCY 5 304 PDE WAVELENGTH 0 0565600 HOTION COMF IND oo ENG PULSE CODE LINEAR FM CHIEFS Map Projection Data Radiometric Data Signal Data Histograms Data Quality Surimary Leader File Descriptor TIT OTTT T T 1 ri Nia a aa Ka Fo d e r b utto n Current Output Directory Oidata O pe ns sm al New Output Directory Edat Browse selection menu that lets the user Af Cancel Pox browse for an appropriate output directory where the results of the current processing run are to be stored This option applies to all files in the input file list The Add Output File Prefix or Output File Naming Schen O x Add Output File Prefix or Suffix ot Suffix button opens a menu for pet OO defining a naming scheme for the suff uml mm output images These schemes are particularly useful if the user wants to run the same batch of data sets with different X cancel oP ox processing options for a comparative analysis To all the files selected in the input file section a pref
38. PoISARPro the height values conveniently stored in the GRD files and the annotation file are needed For the majority of purposes the GRD files are the most viable data option In the example below we derived the Yamaguchi4 decomposition from a geometrically and a radiometrically terrain corrected and geocoded matrices The visual inspection shows that the radiometric correction not only corrects the geometric distortions but also flattens the decomposition values 64 ASF MapReady User Manual Geometrically terrain corrected Radiometrically terrain corrected Yamaguchi decomposition Yamaguchi decomposition The color representations of polarimetric results within PolSARPro generated as BMP files can differ from the MapReady results in some cases The reason for that is the use of different schemes of mapping floating point to byte values Data compression can play a role in the color difference as well While the visual color representation might vary the actual data values are not affected For more details on the processing strategies Gens R Pottier E and Atwood D K 2013 Geocoding of polarimetric processing results Alternative processing strategies Remote Sensing Letters 4 1 39 45 65 ASF MapReady User Manual 5 ASF View The ASF tool suite contains a basic viewer which can be used to view your CEOS GeoTIFF ASF Internal format and other image format files All image formats supported by MapReady are supporte
39. SAR satellites generally transmit in either a vertical perpendicular to the earth s surface or a horizontal parallel with the earth s surface polarization and then receive in either a vertical or horizontal orientation or both Other orientations such as at other vector angles and elliptical or circular polarizations are generally not available from remote sensing platforms The ALOS PALSAR satellite for example can transmit either horizontally H or vertically V polarized waves and receive either as well The two letter polarization field of the ASF metadata is always one of HH HV VH or VV the first ASF MapReady User Manual letter refers to which polarization was transmitted and the second is which was received For example if H is transmitted and V is received HV we re looking at how the scatterers on the ground changed the polarization of the wave from horizontal to vertical The RADARSAT 1 and ERS 1 2 satellites transmitted and received only a single polarization RADARSAT 1 always sent and received horizontally polarized waves HH ERS 1 and ERS 2 always sent and received vertically polarized waves VV ALOS PALSAR quad pol data contains all four combinations the satellite alternates between the four yielding more information about what is on the ground since various terrain features respond differently to each polarization Note that in trade for this additional information due to bandwidth and storage limitations
40. SF MapReady User Manual The interferometric GAMMA data consists of several data sets The interferogram is stored as complex floating point values interferogram The interferometric GAMMA data consists of several data sets The coherence image is stored in floating point values between 0 and 1 coherence The interferometric GAMMA data consists of several data sets The metadata of the SLC slave image is used to define the temporal baseline slave metadata The interferometric GAMMA data consists of several data sets This file contains the baseline components that describe the geometry of the interferometric pairs baseline The interferometric GAMMA data can be stored in complex form This flag is providing generic support for any complex GAMMA file regardless what nature the data is complex gamma 0 The UAVSAR ingest requires the definition of which product actually needs to be imported POolSAR products SLC MLC DAT GRD HGT InSAR products AMP INT UNW COR AMP_GRD INT_GRD UNW_GRD COR_GRD HGT_GRD Several products can be ingested at the same by listed them comma separated By setting this parameter to all all available products are imported uavsar Polarimetry If you have guad pol SLC data available you can use the standard Pauli decomposition to map the 4 bands to the R G and B channels in the output image In this decomposition t ed is HH
41. Terrain correction water height cutoff 1 0 user mask fill value 0 no resampling 1 use nearest neighbor 1 Geocoding backGround Q70 The most dominant parameters are related to import location of precision state vectors for ERS 1 2 used whenever possible to terrain correction standard parameters for optimum results and to geocoding how to treat the black fill in the imagery The ERS 1 2 precision state vectors can be downloaded from the following web site http www deos tudelft nl ers precorbs 93 ASF MapReady User Manual 7 9 Running asf_mapready in batch mode The ast_mapready tool can be used in a batch mode to run a large number of data sets through the processing flow with the same processing parameters This requires a much shorter configuration file that for the regular processing Most of the configuration options will be specified in a default values file as specified above and the settings found in the default values file are removed from the normal configuration file asf_mapready configuration file General default values cis defaults batch file cis batch prefix test SULT Ix Lee In this case there are only two parameters that need to be defined the default values file as described in the previous section and the batch file Optionally a prefix as well as a Suffix can be defined for the output names With these naming schemes the user can prevent the tool from overwriting results
42. The GAMMA ingest support is mostly for interferograms and ASF Internal coherence images generated with the GAMMA software This input file format also requires the original CEOS data file to have the complete SAR geometry information The support of TerraSAR X and Radarsat 2 is currently experimental It is limited to complex data formats that are required for polarimetric processing As part of the ALOS Kyoto and Carbon Initiative project the Japanese JAXA provides to types of mosaics e PalSAR orthorectified mosaics at 50 m resolution and e PalSAR browse mosaics at 500 m resolution MapReady supports both projections the equi rectangular and the Mercator projection that the data are distributed in It allows the re projection to any of the other supported map projection or the export to the more user friendly GeoTIFF format The file browsing menu with its standard functionality handles the selection of individual or groups of files to be processed Once selected the files are individually listed and thumbnails are generated for each input image __ Browse Most CEOS files have multiple files together which compose the data When selecting files for processing it doesnt matter which of the multiple files you actually select The Input Files will usually list the metadata file for a particular data set regardless of which file you actually selected 30 ASF MapReady User Manual amp Add File Add File to Proces
43. _mapready create lt name of configuration file gt again A fully initialized configuration file has the following parameters asf_mapready configuration file General input file R125419155G1S014 ancillary file 83 ASF MapReady User Manual output file R125419155G1S014 default input dir default output dir project 0 files 0 import 1 external 0 polarimetry 0 terrain correction 1 CaltpraLwon L geocoding 1 export 1 mosaic 0 default values intermediates 0 short configuration file 1 dump envi header 1 tmp dir Import format CEOS radiometry AMPLITUDE_IMAGE look up table lat begin 99 00 tat end 99 200 precise output db 0 complex SLC 0 MULT ELoOok SLG Q apply ers2 gain fix 1 polsarpro colormap image data type metadata file interferogram coherence slave metadata baseline complex gamma 0 uavsar Terrain correction pixel spacing 99 00 digital elevation model mask auto mask water 0 water height cutoff 1 000000 fill value 0 d radiometric 0 smooth dem holes no resampling 0 O 84 ASF MapReady User Manual refine geolocation only 0 interpolate 1 Save terrcorr dem 0 save terrcorr layover mask 0 no matching 0 range offset 0 000000 azimuth offset 0 000000 use gr dem 0 use zero offsets if match fails 0 Save incidence angles 0 Calibration ra
44. all into the general scheme of keeping intermediate products if selected More information about the layover shadow mask is available in the Examples section below 3 1 6 Geocode Tab The geocoding step is an essential step to establish the relation from the SAR image geometry to the real world By transforming the image from the SAR geometry into one 24 ASF MapReady User Manual of the standard map projections the user can use the data set outside the ASF software tools Nevertheless the geocoding of the data is optional The geocoding step is invoked by turning on the Geocode checkbox and selecting one of the available map projections By default a UTM projection is used and the zone number will be determined by looking at the center point of the scene In the summary section this is indicated by lt from metadata gt General Calibration External Polarimetry leram Gorecton Geocode Export Map Projection Albers Conical Equal Area alaska Latitude of Origin 50 000000 Specify Height Central Meridian 154 000000 Avg Height 200 meters First Standard Parallel A Specify Piel Size second Standard Parallel 65 000000 N 7 Pixel Size 125 meters Datum Resample Bilinear Ignore projection errors Eee The map projections that Te are supported by the tool Polar Stereagraphic alacka are listed on the right Albers Conical Equal 4rea AE Lambert Azimuthal Equal Area ee For the UTM projec
45. alues i e in dark or light regions or regions of similarly grey values Because this transform is nonlinear however very small changes in the geolocation of may occur The amount of change is not predictable and is completely dependent on the distribution of the data values in the image but should be quite small i e fractions of a pixel to a pixel in magnitude est 7 7 Default values file The default values file specified in the General block in the configuration file is used to define the user s preferred parameter settings In most cases you will work on a study where your area of interest is geographically well defined You want the data for the entire project in the same projection with the same pixel spacing and the same output format The default values file is essential part of the batch processing described in the next section Here is an example of a default values file that the Canadian Ice Service CIS is using for their automated processing system import 1 Sar processing 0 geocoding 1 export 1 terrain correction 0 background 0 intermediates 0 quiet 0 short CONLIQuULaltOn rile 0 input format CEOS radiometry AMPLITUDE_IMAGE Look p table Jexport cis cls lCeslurt projection export asf_tools share projections utm utm proj pixel spacing 100 height 0 0 datum WGS84 resampling BILINEAR force 0 output format GEOTIFF byte conversion SIGMA smooth dem ho
46. alues file is used to define the user s preferred parameter settings In most cases you will work on a study where your area of interest is geographically well defined You want the data for the entire project in the same projection with the same pixel spacing and the same output format Se SF OSE OSE A sample of a default values file can be located in home rudi tools fresh asf_tools share asf_tools mapready asf_mapready default values 108 ASF MapReady User Manual The intermediates flag indicates whether the intermediate processing results are kept 1 for keeping them 0 for deleting them at the end of the processing intermediates 0 The short configuration file flag allows the experienced user to generate configuration files without the verbose comments that explain all entries for the parameters in the configuration file 1 for a configuration without comments 0 for a configuration file with verbose comments se SF OSE OSE short configuration file 0 If you would like to view intermediate imagery you may wish to turn this option on it dumps an ENVI compatible hdi file that will allow ENVI to view ASF Internal format img files These files are not used by the ASF Tools dump envi header 1 The tmp dir is where temporary files used during processing will be kept until processing is completed Then the entire directory and its contents will be deleted tmp dir Import t T
47. ameters overwrites the results from this matching step 7 5 Geocoding The geocoding tool currently supports five different map projections Universal Transverse Mercator UTM Polar Stereographic Albers Equal Area Conical Lambert Conformal Conical and Lambert Azimuthal Equal Area For all these map projections a large number of projection parameter files have been predefined for various parts of the world The projection parameter in the geocoding block indicates the file name of the predefined projection parameter file Users can define their projection parameter file using the text editor of their choice On Unix systems the projection parameter files are located in the asf_tools share asf_tools projections lt projection gt directories while on Windows systems they are located in the projections lt projection gt directories in the ASF Tools installation folder by default this is c Program Files ASF_Tools The projection parameter file for the UTM projection is a special case It contains an empty zone parameter in which case asf_geocode determines the zone from the center longitude of the image It allows the use of any other zone for the geocoding as long as that zone is covered in the imagery For these cases the user can define the zone parameter in the generic UTM projection file The pixel spacing determines the pixel size used for the resulting geocoded image and therefore the size of the output image The default setting of 99 0
48. and determines any differences between the two metadata files farcorr This is the program that performs Faraday Rotation correction This correction must be applied to amplitude data attempting to apply it to data that has already been calibrated will not work If you want to have the data calibrated the calibration options normally given to asf_import can be given to farcorr fftMatch The fft_match program determines the offset between two images in the same geometry to a sub pixel precision The offset in x and y with the confidence level of the correlation can be stored in a file using the m option The correlation quality can be visually checked by saving a correlation image using the C option A correlation with a high confidence level should show up with a star shape pattern around the center of the correlation image fill holes 101 ASF MapReady User Manual This program is used to smooth over missing data values in DEMs SRTM DEMs frequently contain a number of missing data regions this program can be used to fill in those holes with bilinearly interpolated values The interpolation is done by taking a weighted average of the four nearest in each of the up down left and right directions DEM values to the missing point This is used by MapReady to implement the Fill DEM holes with interpolated values checkbox in the Terrain Correction tab flip The flip tool allows the user to flip an image in horizontal an
49. andeuentusdssenteadetealunauianlvadadintowteviattateventiedctnteades 100 aS VCW tits rds E E E T E E 100 DOADO eaa a EEE E E 100 COMODINO isi aioe EEEE EEEE 100 AG SKOW secs ces E E TTO TE oes eee 100 OUI AG Ce sesgaectasstecatacnsacssaeudoaafoadncadoeuauaatouncwaadecsneataentoatooa dace EEE EE OEE 101 ITN e EA EAA AN EE EE EEE EAE E AAE E EE 101 CO ena E teases tan senate saatstetoten 101 MAO eens ne ere ree ee eee eter ee tee 101 PUN NOIE Ssa a cresiertdb aie meee een andes Meyees Senne Ringe Gere eee 101 AIEA oe en oe eC ern SR I A Rr AN te ree ert eee ete eter or ere 102 SONG AOS e EAA E E acid aacawarceuesuasela 102 OLE 50212 LY meee es ste ee ne ee re O eee 102 metadades E T osceorniescsarsiancsarsiexccar sin adavoiaearsionciassiercusrsiasst 102 MOSAIC dinsswetiscnndionmemeiv ene 102 enne GC OlOC ATOM rae atest valtina senate e uals nack a tune memenesinaaeia ene 103 GEE ih 8 See PP ORYE TEV ECE PEE CRIT CEPT PLCC RIE TNT ETRY TRU O EE TPIC EIT RIT RET OPEC EEE 103 SHITE lt GCOlO CATON cira E E E 103 SMOOT 104 P Os E E T E E ES 104 O T E E ET E Geen eeeeaes 104 MMMM E EEEE EEE EEEE EAE ETE EE AE EEE EE EEE TE EE E 104 WCDI EAEE EEIE EE AE 104 9 Handling multi band files with the command line tOols ccccecseeeeseeeeeeeeeeeeeens 106 Appendix A Configuration File Example ccccccsecceceeeeseeeceeeeeeeeseeesaaeeeseaeeeseaes 107 Appendix B MapReady functionality cccccescccseeeceeeeseeeeceeee
50. arameters are entropy anisotropy and alpha ASF MapReady User Manual Entropy is an indication of the degree of randomness in the scattering process Low entropy means there is a single dominant scattering mechanism in that pixel high entropy means multiple scattering mechanisms are present in the pixel Anisotropy represents the relative importance of the non dominant scatterers When entropy is low the anisotropy parameter means very little but for high entropy it is a useful indication of the strength of the secondary scatters Alpha can be used to identify what type of scatterer is the dominant one When alpha is close to 0 single bounce scattering e g a rough surface is dominant For alpha near 90 the dominant scatterer is double bounce Alphas in between these extremes represent a combination of both at 45 we have equal amounts of both which usually corresponds to volume scattering The Cloude Pottier parameters can be obtained directly skipping the classification by selecting the Entropy Anisotropy Alpha option This is the only option where you may assign RGB channels yourself or choose to export three separate grayscale images one for each of entropy anisotropy and alpha with the other polarimetric decompositions the RGB channel assignment is determined by the decomposition some of the intermediate files generated for the Cloude Pottier Decomposition are useful and are described in the Examples below Fo
51. ata that serve as input to the processing flow It consists of a number of components describe here in more detail r Input Files WS r z p Add CEOS Level 1 _ Browse l Ee Output Settings Destination Folder Add Output File Prefix or Suffix Input File Bands Output File LED ALPSRPOGS3713510 H1 5_U4 HH HY ALPSRPOSSS71310 H1 5_U tiF The user can choose from a variety of data formats from a drop down list CEOS Level 1 AirSAR UAVSAR PolISARPro GAMMA ROL PAC TerraSAR X Radarsat 2 ALOS mosaic GeoTIFF and ASF Internal 29 ASF MapReady User Manual In the current implementation of the CEOS data ingest only the processing of CEOS level one data which includes SLC data which is the default value is fully supported additional tools are required to take full advantage of the CEOS level zero and STF data CEOS Level 1 AirSAR data was acquired in a number of modes MapReady ASAR supports the topographic data also referred to as TOPSAR data AA which contain interferometrically derived DEMs The other format is the polarimetric data that has been collected a number of caries wavelengths GAMMA ROLPAC UAVSAR data are acquired in two different modes the polarimetric TerraSAR X mode and using repeat pass interferometry RPI For both modes Radarcat there are a number of product types available that can be individually selected ALOS mosaic GeoTIFF
52. ate 06 Oct 06 orbit 3726 orbit direction D frame 3110 band count 4 hands O1 02 03 04 line count 8480 sample count 8574 start line oO start sample x pixel size 10 Yopixel size 10 center latitude 4 37832386 center longitude 7 7615061 re major 63781356 re Minor 6356751 bit Fror rate nan Imaging mode Hane and Version of Processor Type of samples fte g BREALE4 Image data type fe gq AMPLITUDE IMAGE System of samples e g big ieee Acquisition date of the data Orbit Mumber for this datatake Ascending A or descending D Frame for this image l if n a Mumber of bands in image Band of the sensor Mumber of lines in image Mumber of samples in image First line relative to original image First sample relative to original image Fange pixel size m Azimuth pixel size mw Approximate image center latitude Approximate image center longitude Major equator Axis of earth m Minor polar Axis of earth m Fraction of bits which are in error missing lines 999999999 Mumber of missing lines in data take mo data nan Value indicating no data for a pixel End general E HE H H H H H H H H H H HHRHH HHHH HHH p The View output button opens the output viewer that allows the user to inspect the output images See the section on ASF View below for information about the viewer application The Display in Google Earth button launches Google Earth zoom
53. ation file that has had similar entries removed i e define geocoding map projection parameters in the default settings file but delete the Geocoding block and its parameters found in the regular configuration file Note that if you take this approach that you would still for this example leave the geocoding flag in the General block of the normal configuration file set to 1 The difference is that the appropriate parameters will be found in the default settings file instead If you perchance ran asf_mapready with the create flag again however then the Geocoding block would be automatically added back to your configuration file Take a look ata configuration file and at the default settings file provided by the ASF and experiment a bit to clarify how things work You can find the default settings file provided by the ASF in the ast_mapready subfolder of your share directory located where previously mentioned in this document 92 ASF MapReady User Manual 7 8 MapReady settings file There are a number of settings that are more permanent than the parameters stored in the default values file As with the default settings file you can find the MapReady settings file mapready_settings cfg in the asf_mapready subfolder of your share directory General data directory lt enter directory name gt IMEOIE precise orbits ERS 1 precise orbits ERS 2 lt loca rOn Of eres TLIE lt locat Lom Of arclisr file gt
54. cs at a time but never all of them Selecting an appropriate map projection allows them to be suitable for certain applications and or geographical regions Cylindrical projections work best in equatorial areas The Universal Transverse Mercator UTM projection is the most commonly used one from this family of map projections The distortions within the UTM projection are manageable as long as the projected area is not very large Conic projections commonly defined with two standard parallels are often used in the mid latitude regions In this case the Albers Conic Equal Area projection preserves area while the Lambert Conformal Conic projection preserves angles Azimuthal projections are mosily used in the Polar Regions The Polar Stereographic projection and Lambert Azimuth Equal Area projection are well known representatives of this type of projection The ASF MapReady software currently supports five of the most commonly used map projections e Universal Transverse Mercator UTM Albers Conical Equal Area Polar Stereographic Lambert Conformal Conic Lambert Azimuthal Equal Area 2 5 Polarization ALOS PALSAR data can be obtained which uses multiple polarizations to image a scene including dual pol two different polarizations and quad pol four different polarizations The term polarization refers to the orientation of the electric E field vector in the electromagnetic wave signal emitted by conventional radar systems
55. ction the first tab displayed is the metadata section containing information about the image being displayed The Help tab as discussed above lists the commonly used keyboard and mouse shortcuts Meta Meta Stats map Display GoTo Help The meta tab contains a subset of the Size 6192 x 8192 Lx5 relevant metadata This provides some basic Data Type Byte see eee information about the displayed data set Mode STZ Acquisition Date 07 Feb 2006 16 38 20 Orbit Frame 53567 1300 Direction Descending Bands Polarization HH Look Direction R Look Count 4 Deskewed Yes Range Time Pixel 5 415094e 008 5 Azimuth TimelPiel 0 001890 5 Slant to First Pixel 568918 8 m PRF 1254 2 Hz Earth Radius 6362150 m Meta Stats map Display GoTo Help Size 7614 x 5699 Lx5 Data Type Byte Sensor GEOTIFF Bands INTERFEROGRAM PHASE Satellite Height 7163059 m Above Earth 800909 mi Interferometry information Processor ROT Pac Master image 4LPSRPUG6311150 Master acquisition date 2007 09 71 Slave image ALPSRPO 4391 130 Slave acquisition date 2007 06 21 Center look angle 36 0583 degrees Doppler 60 6821 Hz Doppler Rate 0 00795467 Hzim Baseline Length 473 1 m Baseline Parallel 247 6 m Baseline Parallel Rate 0 00004630 mis Baseline Perpendicular 395 0 m Baseline Perpendicular Rate O 00009076 mis Baseline Temporal 90 days Baseline Critical 9469 9 m Colormap Embedded
56. d attempts to mask the regions of your scene that are water those regions which may result in a poor match Specifically all DEM height values of less than 1 meter are masked out You may instead force the automatically created mask to mask out all terrain below some other height by specifying a different water height cutoff in the terrain correction block of the configuration file When applying a mask during terrain correction you can choose how the regions covered by the mask are filled in in the final terrain corrected result If you would like the SAR data to be kept then use 1 as the fill value otherwise enter a value that you d like to use instead The terrain correction is applying a geometric correction to the data In addition to that the data can be radiometrically corrected for the effects of the local incidence angle For this the do radiometric flag needs to be set Digital elevation models acquired by the Shuttle Radar Topography Mission SRTM have holes in identified problem areas This can cause some streaking in the terrain corrected product Setting the smooth dem holes parameter replaces the DEM holes with interpolated values The terrain correction is down sampling the DEM if it is significantly larger than the SAR image This behavior can be overruled by setting the no resampling parameter When applying terrain correction to low topography flat regions the results may not be entirely accurate In these cases the r
57. d by ASF View 5 1 Running ASF View ASF View can be started from within MapReady using the View Input and View Output options in the files sections Select a file then click the appropriate button or use the right click menu ASF View will start up and display the selected file For Windows users there is a shortcut for ASF View in the ASF Tools start menu group After starting ASF View select the Open File button to and load in the file you wish to view For imagery with more than one file such as CEOS images you can choose any of the files For example to load a Radarsat CEOS file you can select either the D file the data file or the L file the leader file Finally ASF View can be started on the command line The file you wish to view can be given as the argument For example to run ASF View and load file1 D asf view filel D 5 2 Using ASF View The ASF View window contains 4 sections On the right there is the main viewing window Initially this is a 1 1 view of the center of the image On the left there are three vertically stacked sections the full image thumbnail an information section containing information about the currently selected point the crosshair and a tabbed section with more detailed image information Immediately below the full image thumbnail is a row of buttons The rightmost button is the Open File button the others are discussed below Under the tabbed section there is
58. d or vertical direction geoid_adjust Most digital elevation models such as SRTM are geoid based and require a correction before they can be used for terrain correction The geoid_adjust tool applies a geoid correction so that the resulting DEM relates to the ellipsoid meta2envi ENVI is capable of reading the flat binary img files used in the ASF Internal Format however the metadata file is different This program converts an ASF metadata file which has a meta extension to an ENVI metadata file which has a hdr extension At that point the hdr file can be paired with the img file which doesn t need to be changed and loaded into ENVI By default MapReady will produce hdr files for all intermediate files produced during the processing So if you have saved intermediate files these intermediate files may be loaded directly into ENVI using the generated hdr files together with their associated img files metadata This program is a command line implementation of the CEOS Metadata Viewer it retrieves and displays the CEOS information from the CEOS leader files mosaic 102 ASF MapReady User Manual The mosaic program mosaicks the given input files together producing an output image that is the union of all the given input images It also requires that you specify a map projection for the output images and all input images will be geocoded to that projection while being mosaicked The ast_geocode program i
59. d selection of bands for the R G and B channels in the output image By setting the truecolor flag band assignments will be R 3 G 2 and B 1 and each band will individually contrast expanded using a 2 Sigma remapping for improved visualization use rgb banding if you desire raw data assignments Se OSE H H H truecolor 0 If you have 4 bands available in your optical data you can create the exported file using a standard selection of bands for the R G and B channels in the output image By setting the falsecolor flag band assignments will be R 4 G 3 and B 2 and each band will individually contrast expanded using a 2 Ssigma remapping for improved visualization use rgb banding if you desire raw data assignments Se HHH HE SFE falsecolor 0 If you wish to export a single band from the list of avelilab he bands iG HH HV VA VV w center VV CO expore just the VV band alone band 116 ASF MapReady User Manual Appendix B MapReady functionality Input data formats GUI CEOS level 1 GeoTlFF AirSAR UAVSAR ALOS mosaic TerraSAR X Radarsat 2 PolISARPro GAMMA ROL PAC ASF internal config file CEOS STF Geo TIFF BIL GRIDFLOAT AirSAR UAVSAR VP ALOS mosaic TerraSAR X Radarsat 2 PolISARPro GAMMA ROL PAC ASF internal Output data formats GUI TIFF Geo TIFF JPEG PNG regular PGM PoISARPro command line CEOS STF Geo TIFF BIL GRIDF
60. default method uses a statistical approach that eliminates any outliers that are outside of two standard deviations around the mean This approach produces satisfactory results in most cases Alternatively the original dynamic range of the image with its minimum and maximum value can be mapped into the byte value range of O to 255 When exporting mask images the values can most often simply be truncated without any loss of information Histogram equalization is a nonlinear rescaling method designed for maximizing visibility of the details in the image Histogram equalization will help expose detail in regions where the local dynamic range is low i e extra dark or extra light regions that Statistical 2 Sigma MinMax Truncate Histogram Equalize General Import Settings External Palarimett Jerman aane caa Geocode Export Export Format JPEG f jpq z I Output data in byte format finstead of Floating point Sample mapping method Statistical Sigma gt Export All Bands as Separate Images C Export RGE Image according ta Polarimetric selection Export Multiple Bands in a Single RGE Image User Defined 1 True Color 1 False Color Red Band Green Band 7 Blue Band 28 ASF MapReady User Manual tend to hide fine detail will have the local contrast expanded over a broader range of values which highlights detail previously difficult to see For images containing multiple bands the u
61. diometry AMPLITUDE woods hole scale 0 Geocoding projection asf_tools share asf_tools mapready projections utm utm proj pixel spacing 99 00 height 0 0 resampling BILINEAR background 0 s 00 force 0 Export format GEOTIFF byte conversion SIGMA rgb look up table rgb banding truecolor 0 falsecolor 0 band In this case all four processing steps will be performed i e importing terrain correction geocoding and exporting of the data set in a new format Since we don t have SLC data the polarimetry option is not turned on The values for each option are given here in all capital letters however the processing is not case sensitive you may use lower case values for options if you prefer The MapReady GUI generates configuration files in order to process each image If you have turned on the Keep Intermediate Files option the directory where the intermediate files are stored will contain a configuration file based on the settings selected from the GUI 85 ASF MapReady User Manual 7 2 Import CEOS STF GEOTIFF ASF AIRSAR UAVSAR ALOS MOSAIC TERRASAR RADARSAT2 GAMMA AND POLSARPRO are the most supported import formats selecting the ASF Internal format is just another way of actually skipping the import step rather than having to have the original format file The only CEOS format that currently makes sense to include in the processing flow is the CEOS level one data The process
62. e Keep no intermediate files option the intermediate files are deleted as soon as processing completes This was the default behavior in earlier versions of MapReady This means the View Intermediates menu in the Completed Files will not be available This option should be used if you are going to process a number of files and are concerned about disk space since the intermediate files can take up quite a bit of space The Keep intermediates option means that the intermediates will never be deleted The Show full path name checkbox at the bottom of the general tab determines whether the input file names displayed in the input and completed file sections include the full path name or are limited just to the file name itself By default the path names are hidden The Generate and show thumbnails checkbox determines whether thumbnails are generated for all input and output images By default these are generated Show full path names Generate and show thumbnails The About MapReady button on this tab opens the About dialog which contains contact information for the Alaska Satellite Facility and the version number of the software ASF MapReady User Manual 3 1 2 Calibration Tab Note that all processing other than the import step requires the data to be in the ASF Internal Format file format This is in fact what the import step accomplishes additionally applying the selected radiometric calibration The result
63. eady checks the Wishart_H_Alpha_6 selected file In case no map projection information is found the tishar H_A Alpha_1 Original data file needs to be selected to provide the necessary information about the SAR geometry This extra information is required to perform the terrain correction or the geocoding of the data If the data is already geocoded it can only be re projected and or exported to a different format After the files and color map are selected the input files will show up in the input file section Input Files P m F F Add FPolSARPro Lo Browse Ey Output Settings C Destination Folder Add Output File Prefix or Suffix Input File Ancillary Files Bands Output File wishart H 4 alpha class 3 bin LED ALPSRPO41726820 P1 1 4 9 4 wishart_H_4 alpha class 3 tif The import of files generated by the GAMMA software requires some additional information as well Therefore a GAMMA specific file selection pop up window needs to be filled out In the input file section the additional ancillary files show up in a separate column 32 ASF MapReady User Manual af Add File Add File to Process Data Format GAMMA Amplitude Data F data 235170660 mli GAMMA Amplitude Metadata F data 2351 0660 milipar GAMMA Interferogram F data 12 810660_ 194910660 int GAMMA Coherence F data l27810660 194910660 cc GAMMA Slave Metadata GAMMA Baseline FO Parameters in bold are required All ot
64. eference DEM might still be used to improve the geolocation of the SAR image without performing the actual terrain correction This can be achieved by setting the refine geolocation only flag With this option the image data is not changed at all only the geolocation information in the metadata is affected Layover and shadow regions are problem areas in images that are in the original SAR geometry since the backscatter information is either heavily condensed or missing In the terrain correction process they can either be left black resulting in better image Statistics in the remainder of the image or they may be interpolated over resulting in a 88 ASF MapReady User Manual nicer looking image Setting the interpolate parameter to 1 indicates that these regions should be interpolated over For a more detailed analysis of the terrain correction results a couple of files used in the process can be saved Setting the save terrcorr dem parameter keeps the clipped to the SAR image extents reference DEM in slant range geometry Setting the save terrcorr layover mask parameter keeps the layover and shadow mask There are few parameters that can be set to overwrite the standard matching procedure that is carried out during the terrain correction The no matching parameter eliminates the processing step that applies the offsets that the program determined between the real and a simulated SAR image Using the range offset and azimuth offset par
65. egions save layover shadow mask save clipped DEM define water mask cut off define fill value no resampling define azimuth and range offsets use of nearest neighbor interpolation use of ground range DEM command line amplitude sigma beta gamma db scaling command line DEM file fill DEM holes terrain correction refine geolocation different tools apply water mask apply mask file use FFT matching specify pixel size apply radiometric terrain correction save incidence angle interpolate layover shadow regions save layover shadow mask save clipped DEM define water mask cut off define fill value no resampling define azimuth and range offsets use of nearest neighbor interpolation use of bilinear interpolation use of ground range DEM use of slant range DEM generate simulated image without speckle keep intermediate results update original metadata apply offsets to other file Woods Hole scaling to byte Woods Hole scaling to byte 119 ASF MapReady User Manual Map projections GUI Universal Transverse Mercator Polar Stereographic Albers Conic Equal Area Lambert Azimuth Equal Area Lambert Conformal Conic config file Universal Transverse Mercator Polar Stereographic Albers Conic Equal Area Lambert Azimuth Equal Area Lambert Conformal Conic Equidistant Equi rectangular Google Earth Geographic Mercator Sinusoidal Geocoding GUI config file map projection parameters specifi
66. elp cloude16 clouded dem Fuzzy Means_6 H_ Alpha Lambda H_4 Alpha 9 interferogram layover_mask polarimetry Supervised Wishart_16 unwrapping mask Waker mask Wishart H_ Alpha 6 Wishart Ho Alpha 16 Table option can be used to convert a grey scale image to color using a look up table which maps each grayscale value to RGB values Multi Band Image Bands 01 07 03 04 0 Display Single Band as Greyscale Band 01 ia Combine Bands into RGB Red 03 Green DZ Blue oO Multilook Appl a Look Up Table Hone 17 ASF MapReady User Manual GoTo The GoTo tab simplifies the cursor navigation within the image The location can be selected as e lat lon coordinate e line sample position e map projected coordinates The Plus button adds the location to the current path This allows the user to define polygons for generating subsets Help The Help tab summarizes the mouse and short key functionality Meta Stats map Display oto Help Move Crosshair To Lat Lon O T jel Line Sample 1000 1000 i dh Projected X Y O T lel Meta Stats map Display GoTo Help Left Click Place crosshair Left Click amp Drag Pan image Ctrl Left Click Place secondary crosshair s Right click Re center view Scroll wheel Zoom infouk Arrow Keys Move crosshair 1x Ctrl 4rrows Move crosshair 10x ShiFt 4rrow Move crosshair 25x Ctrl Sh
67. ement of the restituted State vectors that are provided from the European Space Agency The parameter 109 ASF MapReady User Manual required here defines the location of the precision state vectors precise When the output db flag is non zero the calibrated image is output in decibels It only applies when the radiometry is sigma gamma or beta output db 0 When the complex SLC flag in non zero single look complex data is stored in I Q values Otherwise SLC data will be stored as amplitude phase complex SLC 0 When the multilook SLC flag in non zero single look complex data that is stored as amplitude phase is being multilooked multilook SLC 0 The ERS2 satellite has a known gain loss problem that this program will attempt to correct if this option is turned on by applying a scale correction factor uniformly to all pixels in the image The correction is dependent on the date and is only applied to calibrated data 1 e everything but amplitude For more information see section 4 of lt http www asf alaska edu reference dq Envisat_symp_ers2_performance pdf gt Se OSE OSE SHE H H H apply ers2 gain fix I If any input files are PolSARpro files then it will be a single band greyscale image containing a PolSARpro classification In order for the Classi rica t on to be properly colored a PolSARpro look up table should be specified here For a full list of available PolSARpro
68. emporary files one will have been created and placed in the temporary directory Also 99 ASF MapReady User Manual the predefined projections used by MapReady and the Projection Coordinate Converter located in the projections folder in the MapReady installation directory can be used asf_terrcorr The asf_terrcorr program terrain corrects or orthorectifies the SAR data from its original side looking time based geometry radar to an orthogonal nadir view so that it aligns nicely with photographic images It takes a SAR image and a digital elevation model DEM as input A simulated SAR image is created based on the DEM using the satellite s oribit information state vectors The SAR and simulated SAR are then corregistered matched Based on that coregistration the values of each of the SAR pixels are painted in the location of the corresponding pixel of the original DEM This utility performs the functionality availabe in the Terrain Correction tab of MapReady and the Terrain correction section of asf_mapready asf view This tool is described in more detail in a previous section brs2jpg The brs2jpg tool converts ALOS Palsar browse images BRS located in the BROWSE directory of the respective data product into JPEG format The information about the browse image dimensions is stored in the workreport file that is required as an input file combine This program mosaics the input files together producing a
69. eparated columns lf you have selected only one additional point i e your polygon is nothing but a line segment then the Save Subset dialog will assume you wish to save the rectangle which has a diagonal of the selected line segment In this case the Strict Boundary button discussed below is disabled After selecting Save Subset the portion of the image that is going to be saved is shown with a purple boundary 71 ASF MapReady User Manual In this example the defined polygon has four points and the purple subset to be saved is the smallest rectangle that contains the four points lt is possible to use the tab amp arrow keys as described above to fine tune the polygon while the Save Subset dialog is open before the subset is saved Once you are satisfied with the polygon there are a few more options available in the Save Subset dialog Format The format for the saved subset can be Format ASF Internal C CS either ASF Internal or CSV 12 ASF MapReady User Manual The ASF Internal format is an image format used by ASF to store files during conversion from CEOS to GeoTIFF or whatever output format It is a generic binary format the file extension will be img with a separate metadata meta file You may view these files with ASF View Alternatively you can use the command line tool meta2envi to generate a hdr file from the meta file and view the img hadr file combination with
70. ermissions within URSA in order to apply the newly generated processing parameter file OBJECT PROCESSING_PARAMETERS OBJECT COMMON_HEADER MSG_TYPE PROCESSING_PARAMTERS LIME 1990 001TO0 00201 SOURCE WRITE_PPF DESTINATION SPS NUMBER_OF_RECORDS 1 104 ASF MapReady User Manual BND OBJECT COMMON_HEADER PLATFORM RADARSAT 1 REVOLUTION 61820 FRAME ID 193 PRODUCT_TYPE UNKNOWN IMAGE TYPE U NO_BEAMS 4 BEAM WD1 BEAM2 WD2 BEAM3 ST5 BEAM4 ST6 PRF1 1 287789e 03 PRF2 1 325829e 03 PRF3 1 287020e 03 PRF4 1 329921e 03 ALT_DOPCEN 1 7984526703 12030459Ee 01 0 000000EF00 ALT DOPCEN DELTA 0 0000006700 0 000000E700 CRI DORGAN 2 2046156702 9 050636e 01 CRT_DOPCEN_DELTA 1 287789e 03 Q 000000e 00 ALT_RATE 1 6234226703 4 5000006 06 BEND OBJECT PROCESSING PARAMETERS 0 0000006700 1 181000e 04 0 000000e 00 Le VUOVOUGE 0 7 CRT_RATE 2 106838e 03 1 014572e 01 2 000000e 06 105 ASF MapReady User Manual 9 Handling multi band files with the command line tools The asf_import asf_geocode and asf_export tools all have a band option that allows the user to apply their respective functionality to a single band if the passed band identifier can be found in the multi band image Command line asf_import band 4 ALAV2A037283110 01B2G_U bahamas Importing ALAV2AQO 7283 1L0 0LB2G U Data format CEOS File
71. f keeping intermediate results for further analysis e g errors warnings and results of each processing step During each run these intermediate files are kept in separate subdirectories for each data set In order to ensure that intermediate results are not accidentally overwritten by consecutive processing of the same input files the names of the subdirectories are created with a new date and time stamp The intermediate files themselves have descriptive names that should make it easy to identify the files for further analysis ASF MapReady User Manual 3 Using the MapReady Graphical User Interface The graphical user interface GUI of the MapReady package provides the user with a convenient and interactive way to convert SAR data from their specific CEOS or STF format explained in detail in the background section into more user friendly formats that the majority of software packages dealing with images and their processing and analysis are able to handle As part of the conversion process the user can perform a number of modifications that make SAR data more powerful to use These modifications include e Converting the digital numbers of an image into radiometrically calibrated values e Converting the image from its SAR geometry into a map projection i e geocoding it e Correcting the SAR image for its geometric distortions using a digital elevation model i e terrain correcting it e Extracting polarimetric classifications from i
72. f the SAR image is good enough for terrain correction This often produces good results especially if the terrain is fairly flat When this option if turned off i e set to zero the default terrain correction will abort with an error if the coregistration fails Se SE H H H H H use zero offsets if match fails 0 Turning this on saves an intermediate product with the 114 ASF MapReady User Manual incidence angles and correction factors determined during radiometric terrain correction Use this option only when radiometric correction is turned on Save incidence angles 0 Calibration The radiometry can be one of the following AMPLITUDE_IMAGE POWER_IMAGE SIGMA IMAGE GAMMA IMAGE and BETA IMAGE The amplitude image is the regularly processed SAR image The power image represents the magnitude Square of the amplitude of the SAR image The sigma gamma and beta image are different representations of calibrated SAR images Their values are in power scale radiometry AMPLITUDE_IMAGE This parameter indicates whether the data is scaled back to byte using a formula developed by Woods Hole woods hole scale 0 Geocoding The geocoding tool currently supports five different map projections Universal Transverse Mercator UTM Polar Stereographic Albers Equal Area Conic Lambert Conformal Conic and Lambert Azimuthal Equal Area For all these map projections a large number of pro
73. gories Cloude Pottier classification with 16 categories C Entropy Anisotropy Alpha C P without classification C Freeman Durden canopy layer rough surface In this example we will not apply Terrain Correction or Geocoding though both of these do work on SLC data including SLC data to which youve applied a polarimetric decomposition The results of the processing are shown below 57 ASF MapReady User Manual The interpretation of the result is aided by some of the intermediate files that MapReady makes available When performing the Cloude Pottier decomposition one intermediate is the Classification Map available through the right click context menu of the completed files section Data File F polarimetry washington LEC ALPSRPI Remove metryiwashington4LPsRPOSOFO2830 P1 1_ D jpg Done Queue For Reprocessing View Log View Intermediates Display ASF Metadata view Output view With Google Earthitrn a View Layover Shadow Mask view Clipped DEM View Simulated S4R Image View Faraday Rotations View Entropy alpha Histogram View Entropy alpha Class Map The classification map for this data set is shown to the right This image has entropy values ranging from 0 on the left up to 1 on the right on the horizontal axis and alpha values ranging from 0 on the bottom up to 90 on the top on the vertical axis Low entropy corresponds to a single dominant scattering mechanism
74. he recognized import formats ares ASF CEOS STF ALRGAR GHOTIFE ALOS_MOSAIC TERRASAR RADARSAT2 GAMMA or POLSARPRO Defining ASF being the internal format as the import format is Just another way of actually skipping the import step For AirSAR you can configure which products are processed with the AirSAR block format CEOS The radiometry can be one of the following AMPLITUDE_IMAGE POWER_IMAGE SIGMA_IMAGE GAMMA IMAGE and BETA_IMAGE The amplitude image is the regularly processed SAR image The power image represents the magnitude square of the amplitude of the SAR image The sigma gamma and beta image are different representations of calibrated SAR images Their values are in power scale Se HHH H H radiometry AMPLITUDE_IMAGE The look up table option is primarily used by the Canadian Ice Service CIS and scales the amplitude values in range direction The file parsed in to the import tool is expected to have two columns the first one indicating the look angle with the corresponding scale factor as the second column Se SF OSE OE H look up table The latitude constraints lat begin and lat end can only be used when importing level zero swath data STF This is the most convenient way to cut a subset out of a long image swath lat begin 99 00 lat end 99 00 The precise option currently under development will allow the use Of ERS precision state vector from DLR as a replac
75. her parameters are optional All files are assumed to have the same dimensions If the interferogram or coherence image ts multilooked the multilooked version of the amplitude is expected as required input The metadata of the slave image and the baseline file are needed to pass along InSAR metadata when exporting an InSAR stack to the Geo TIFF format X Cancel ox ROI PAC is another SAR interferometric software whose data can be ingested in MapReady As the ROI PAC scripts follow predefined naming conventions the ingest function only requires a metadata file rsc Immediately to the right of the Browse button is a toolbar containing buttons to help to get the data sets organized for the processing g The Remove button deletes a file from the processing list This becomes necessary for example when the input thumbnails even though they are small reveal that the selected image does not contain a certain feature or the area of interest All selected files are removed The Process button starts the processing of the selected data set rather than processing the entire list of files see Execute button for details This feature is particularly useful when a few data sets out of a long list did not successfully process with the current sets of options and parameters After selecting the appropriate values the data sets can be individually re run using this feature The Rename button lets the user indiv
76. ibration Eterna Polarimetry Terrain Correction Geocode Export Perform a Polarimetric Decomposition Pauli Decomposition HH VV HV VH HH VV Sinclair Decomposition HH HV VH 2 VV Cloude Pottier classification with amp categories B B C Cloude Pottier classification with 16 categories C Entropy Anisotropy Alpha C P without classification B Freeman Durden double bounce canopy layer rough surface When the Polarimetry tab is active the Export tab s RGB options changes to Export RGB Image according to Polarimetric selection This means that the RGB channels in 18 ASF MapReady User Manual the final result are determined by the polarimetric decomposition The channels and how they are calculated from the input quad pol data are listed next to the radio button on the Polarimetry tab For example for Pauli the red channel is calculated by subtracting the complex VV band value from the complex HH band value and then determining the magnitude of the resulting complex value All of the polarimetric decompositions require SLC data except Sinclair The polarimetric calculations will multilook the data since many of the calculations require that the data be ensemble averaged MapReady performs the ensemble averaging using the multilooking window For ALOS PALSAR this means we are using an 8x1 ensemble average but no smoothing occurs each pixel is only used once and the output has 1 8 the number of li
77. idually rename the output images of a run This feature is mostly used when the same input data set is run with different options and parameters without overwriting any of the previous results For renaming a large number of files see the details on naming schemes 33 ASF MapReady User Manual a The View log button allows the user to display the log file once a data set has been processed The log file contains the feedback from the individual functions called as part of the processing flow The log file is the single most useful piece of information for troubleshooting problems as it contains the error messages that the tool issues in case the processing needs to be aborted The Display CEOS metadata button launches the ASF metadata viewer The viewer reads the CEOS leader file a partially binary and partially ASCII file that contains the metadata associated with the binary data see Viewing the Leader Data below l The View Input button launches the ASF viewer asf _view to view the selected input file The Display in Google Earth button launches Google Earth zooms to the image location on the Google Earth globe and displays a blue box which illustrates the image boundaries ry a oF ska geet Ss T fainbanks ala a ae S oa The functionality of the toolbar menu buttons is also available as Remove a right mouse click context menu as shown on the left if you pices right click on a se
78. ies but can easily be as large as a few gigabytes The level zero swaths are then subdivided in frames For ERS imagery these frames have a size of 100 by 100 kilometers which is equivalent to about 26000 lines of radar data The accompanying leader file is defined in CEOS standard format This is why these data sets are referred to as CEOS frames The CEOS data come in three different flavors The CEOS level zero data is raw signal data that needs to run through a SAR processor before it can be visualized The result of the SAR processing CEOS single look complex SLC level one L1 data is primarily used for SAR interferometry as it contains both amplitude and the required phase information Furthermore the data has not been multilooked at this point i e the pixels are not yet square with the exception of RADARSAT 1 fine beam data To be useful for SAR interferometry the data generally needs to be deskewed during the SAR processing The resulting so called zero Doppler geometry ensures that two interferometric data sets can be combined without introducing any further distortions In order to be visualized the data needs to be first converted from its complex form into an amplitude image CEOS level one data L1 is the most commonly used format It does not require any further processing to be useful for regular use ASF MapReady User Manual After ingesting the data all files are stored in an Alaska Satellite Facility ASF Internal for
79. ift Arrow Move crosshair 250x Cer ShiFe Alk 4rrow Move center Tab Toggle which crosshair is moved Esc Clear ctrl clicked path Backspace Remove last ctrl clicked point c Center image on crosshair l Move crosshair bo local maxima 30 30 search area ctri l 300x300 n Toggle north arrow PageUp Down Zoom infouk Home zoom to 1 1 End Fit Image To Window Subset Image Define polygon click Save Subset button 18 ASF MapReady User Manual 6 The Projection Coordinate Converter l ASF Projection Coordinate Converter Select Source Projection Projection Lat Lon User Defined Enter Coordinate Pairs x y height or lat long height Select Target Projection Projection UTM User Defined Enter Coordinate Pairs x y height or lat long height mi Read Coordinates File eh Save to Coordinates File Read Coordinates File we Save to Coordinates File 30 5091 77 0955 a1 7264 44 4264304 62 0 00 30 5697 77 4095 2803111 89 427185521 0 00 af 9277 FF 2500 302249 60 4200160 57 0 00 37 9872 77 6402 260137 13 420 7604 16 0 00 K FC Convert Coordinates fim Convert Coordinates This program is a small utility for converting coordinate values between different map projections To use the program select the coordinate systems you wish to convert between the source and target projections Then the actual coordinate values are entered in the source projecti
80. ing of level zero data CEOS and SIF alike has not been implemented yet Without SAR processing being part of the processing flow any of the other steps are obsolete at this point Supported radiometry parameters are AMPLITUDE_IMAGE POWER_IMAGE SIGMA_IMAGE GAMMA_IMAGE BETA_IMAGE The look up table parameter is primarily used by the Canadian Ice Service CIS and scales the amplitude values in range direction The file parsed in to the import tool is expected to have two columns the first one indicating the look angle with the corresponding scale factor as the second column Here is an example of part of the ice look up table that the CIS is using 0 Sal A e ea 702 22 2442 2 087184476 LI pA DO 8 Corel WOST 6134 D860 DA Ze l 33445 Zso oA A NIOAVOOIF 2S0 AG Zoek IZA 54 Ho Zc OS CeO ERTS d LOLOL AALA TIAN Aoa VOLE Leet OOZaZ 7 L3 I9RO AZ seZ O94 3A0CS Ds MOE 0 Zoi DOO OL LO Sie Zs SLO O 1 9 6 LO EQOA Ayo SIO DOO ZA PISS too d SOW ZOGO00C 2 Dori 7 Subsets can be extracted from swath data STF using the latitude constraints at begin and lat end The precise parameter defines the location of the ERS precision state vector provided by the Delft University of Technology 86 ASF MapReady User Manual When the calibration parameters are applied to the data during the import the resulting values are in power scale The outout db parameter changes this behavior and the values in the output image are stored in GB
81. ion force 0 Export The following format are considered valid format ASF TIFF GEOTIFF JPEG PNG PGM and POLSARPRO In the same way as for the import block ASF as an export option results in Skipping the export step entirely All other formats with the exception of GeoTIFF require the scaling of the internal ASF format from floating point to byte The GeoTIFF supports byte as well as floating point data format GEOTIFF The byte conversion options are SIGMA MINMAX TRUNCATE or HISTOGRAM _EQUALIZE They scale the floating point values to byte values byte conversion SIGMA Applies a look up table to the greyscale values to convert them to RGB using the table in with the given filename Only allowed for single band images Some look up table files are in the look_up_tables subdirectory in the ASF tools share directory The tool will look in the share directory if the given look up table file is not found Se OSE OSE SE H rgb look up table If you have more than one band available in your data you can create the exported file using the different bands for the R G and B channels in the output image List the R G and B channels in that order separated by commas E g HH HV VV Note that no contrast expansion or other modification of the data will be applied Se SF OSE OE SHE rgb banding Tf you have 3 bands available in your optical data you can create the exported file using a standar
82. ious objects is superimposed which leads to a brighter appearance on the image as well Sensor Image plane Shadow The time difference of two signals backscattered at the bottom and the top of a steep slope B A is shorter than from the top to the back side flat area C B Therefore the first two points are mapped to a shorter difference in slant range in the image This geometric effect called foreshortening compresses the backscattered signal energy coming from the foreshortened areas i e the affected areas in the image appear brighter Sensor Image plane Layover The shadow effect in radar imagery is different from optical imagery In the case of radar no information is received from the back slope shown as a black region in the figure to the left The length of the shadow depends on its position in range direction Therefore the shadows in far range are longer than those in near range ASF MapReady User Manual Terrain correction removes these geometry induced distortions by making use of the height information from a digital elevation model DEM The process of terrain correction can be split up in two separate parts geometric terrain correction and radiometric terrain correction Geometric terrain correction adjusts the individual pixels of an amplitude image to be in their proper location i e it places the ridgelines and valleys were they actually geometrically belong MapReady
83. is the active one the red crosshair isn t shown Successive ctrl clicking along the outside edge of the field leads to the TaN PE re AR he Lj Lis Ft ik i a a yee a T h a a rfp m a oe nF il fe i As _ z if L ae ly 4 anol ie Mth ohn a peo Tad Fl ge as i s z py t UE La ite ee closes the polygon To get the circumference the final edge of the field needs to be added to the polygon Information Line 2809 0 Sample 6174 8 Pixel Value 2732 000000 gt 68 Lat 64 1539 Lon 145 8088 deg Incid inf Look 41 6318 deg Slant 987761 1 m Time 3 379 5 Total distance 2137 1 m 6 points Area of closure 300664 2 m 2 The area and circumference of the field are now displayed in the Information section Of course the circumference and area values are only available in meters or square meters if the image being viewed has geolocation information available A JPEG image for example has no geolocation information and so the circumference and area values will be displayed in units of pixels or square pixels 69 ASF MapReady User Manual 5 2 3 Other Useful Keyboard Commands c Center Image On Crosshair Moves the main window so that the green crosshair is in the center Move crosshair to local maxima Features of interest are often at the pixel of highest intensity For example a corner reflector or when viewing a DEM the peak of a mountain Using I note tha
84. ix and or suffix can be added i e to indicate that all files have been geocoded into the UTM projection The Destination 0 x ___ Destination Folder 35 ASF MapReady User Manual A thumbnail is created for the input image In case of multi band imagery the thumbnail is generated for the first band only For multi band images all available bands are displayed in the bands field This simplifies the selection of an appropriate band combination in case the output images are going to be exported as an RGB composite Note that each band in an input file can be viewed separately or as a color composite with the asf_view data viewing tool by clicking the View Input button The user can also monitor the progress of processing the individual data sets as they are processing The status is updated constantly and indicates what processing step is currently being performed In case of an error occurring during processing a short error message is displayed in the status field to indicate what went wrong Once the image is successfully processed it is removed from the input file list and added to the list of files in the Completed Files section 3 3 Completed Files gt Completed Files iw Clear Completed Files Data File Output File Status LED ALPSRP085371310 H1 5_U4 ALPSRPO85371310 H1 5_U4 tiF f up ie Done A number of buttons are available to help analyze the results The Remove butt
85. jection parameter files have been predefined for various parts of the world The projection parameter files are located in home rudi tools fresh asf_tools share asf_tools mapready projections projection nhome rudi tools fresh asf_tools share asf_tools mapready projections utm utm proj The pixel spacing determines the pixel size used for the resulting geocoded image and therefore the size of the output image pixel spacing 99 00 An average height can be defined for the image that is taken into account and adjusted for during the geocoding process height 0 0 Three different resampling methods have been implemented as part of the geocoding NEAREST NEIGHBOR BILINEAR and BICUBIC The bilinear resampling method is the default resampling BILINEAR After geocoding a fill value is required for the regions outside of the geocoded image By default this value is 0 but may be set toa different value here background 0 00 In order to ensure the proper use of projection parameter files we have implemented a number of checks that verify whether the map projection parameters are reasonable for the area that is covered by the data For example applying a projection parameter file that is defined for Se SF OSE OSE 115 ASF MapReady User Manual South America for a data set that is covering Alaska would lead to huge t distortions These checks can be overwritten by setting the force opt
86. l and 2 the image content specifically the amount of topography in the SAR image Without enough topographic features that are accurately represented in the simulated SAR image the ASF MapReady User Manual results of the matching are poor Erroneous offsets from bad matches are more difficult to notice than actual matching failures Radiometric terrain correction without offsets between SAR image and DEM left look homogeneous around ridge lines while residual offsets right show up very bright The size of the residuals give an indication about the amount of offset still remaining For the radiometric terrain correction we follow the approach of radiometric slope correction outlined by Ulander 1996 Surface normal n Image plane normal x x R 10 ASF MapReady User Manual Three dimensional geometry of ground surface and its projection into the SAR image x and R are azimuth and slant range coordinates n is the surface normal is the projection angle and 9 is the local incidence angle after Ulander 1996 The Ulander approach uses the surface normal and therefore the image plane normal is rotationally symmetric This leads to a complete independence from the aspect of the slope for any given pixel The equation for this radiometric correction applied to sigma values in power scale is the following i 2 Torr Oa RTC ot sin a with the projection angle between surface normal and image p
87. lane normal and 8 the local incidence angle The radiometric terrain correction is entirely done using amplitude images to avoid any special cases in the processing flow with respect to radiometry This requires the conversion of the radiometric correction factor from Oo to amplitude For the ALOS Palsar calibration scheme for example this works as follows The calibration equation to generate power scale in sigma radiometry is cf power scale 10 DN with the calibration factor cf and the amplitude digital numbers DN The resulting equation for the radiometrically corrected amplitude DNrag values is power scale radiometic correction factor DN roa 10 10 This approach ensures that values in any radiometry can be calculated by simply applying the respective calibration equation Ulander L M H 1996 Radiometric slope correction of synthetic aperture radar images IEEE Transactions on Geoscience and Remote Sensing 34 5 1115 1122 ASF MapReady User Manual 2 4 Map projections Maps are a two dimensional representation of the three dimensional real world Projecting three dimensional coordinates into a two dimensional space is not possible without distortions in feature shape area distance or direction A very practical illustration of this problem is to lay a carefully peeled orange onto a flat table surface without fracturing it Map projections can preserve some of the above mentioned characteristi
88. lected input file C View Log Display CEOS Metadata View Input View With Google Earthttrn Viewing the Leader Data As mentioned above clicking the Display CEOS metadata toolbar button or selecting that option from the right click context menu will launch the metadata viewer for viewing the CEOS leader file contents The leader file is defined by a number of data records The data set summary record provides general information about the image such as orbit and frame number acquisition date image size and sensor characteristics The platform position data record contains orbital information in form of state vectors that describe the position of the satellite at a given time 34 ASF MapReady User Manual Metadata File F idataitestiE 50541277615002 L Data Set Summar Y e r e e Ae A E e T E T begir O Dataset Summary record e r e T e e e e e a e tres Scene Header Record DSS SEQ NUM 1 SALE CHHL INDTE 1 Platan Poston Data SCENE INDICATOR E250541277G1L8002 SCENE DESIGNATOR Attitude Data INPT SCN CTE TIME 20041Z19712959479 ASC YDESCENDING DESCENDING s LAT OG SCH CTE 62 5063890 Radiometric Compensation Data LONG SCN CTE 150 5311900 CN CTE HEADING z0 0z 9291400 Processed Data Histograms ELLIE DESIGN amp aTOR GENMOS ELLIF SEMIMAIOR B378 1440000 ELLIP SEMIMINGBR B356 7549000 Range Spectra EARTH Mass 298600 5000000 GRAVITATIONAL CNST 8000002 Processing Parameters ELLIF PARM 1 0010826 ELLIF FAFM O 00000z5 ELLI
89. les 1 Note that it is not necessary in a default settings file to group the settings into blocks as in the normal configuration file The block names are there to categorize the settings for reasons of clarity All of the individual settings themselves are unique in their 91 ASF MapReady User Manual naming to prevent ambiguity The easiest way to create a default settings file which is nothing but a simple text file and can use any naming that you desire is to use asf_mapready with the create flag to create a configuration file first Then edit that file and use it as a default settings file It is important to understand the order of events that occur as asf_mapready reads and uses both the configuration file created with the create flag as well as the default settings file that default values field refers to Here is how asf_mapready utilizes the settings in these two files 1 asf_mapready reads the normal configuration file to determine the path and name of the default settings file 2 asf _mapready then reads the default settings file as though it were a normal configuration file 3 asf_mapready then re reads the normal configuration file and allows settings from that file to override the defaults found in the default settings file 4 Processing then continues according to the final combination of settings Perhaps the best way to utilize the default settings file is to use one or more together with a standard configur
90. lex data keep complex data format set azimuth look count set range look count ERS 2 gain correction color map for PoISARPro look up table for range scaling latitude constraint for STF data define image data type for include precision state vectors add extra InSAR files define UAVSAR data type define geographic subset SMAP scaling of input data command line Faraday rotation local global threshold define kernel size keep intermediate results apply calibration after correction Pauli decomposition Sinclair decomposition Cloude Pottier 8 16 categories entropy anisotropy alpha Freeman Durden 118 ASF MapReady User Manual Terrain correction GUI DEM file fill DEM holes terrain correction refine geolocation apply water mask apply mask file use FFT matching specify pixel size apply radiometric terrain correction save incidence angle interpolate layover shadow regions save layover shadow mask save clipped DEM define water mask cut off define fill value no resampling use of nearest neighbor interpolation via settings file Calibration GUI config file amplitude amplitude sigma sigma beta beta gamma gamma db scaling db scaling config file DEM file fill DEM holes terrain correction refine geolocation apply water mask apply mask file use FFT matching specify pixel size apply radiometric terrain correction save incidence angle interpolate layover shadow r
91. leys roads will be incorrect Terrain correcting an image moves features to where they belong using an appropriate digital elevation map DEM as a reference d Me st i k ian ee la eg a Pi Wa E ee P r iF i 7 P Mg r aii y i i A Aa oe 222 p f m ie 1 7 hy i r i E 5 ee Ed oot ea 5 id ptt a m GL e r LA J 45 v ig i ei ave j T 1 yD fea ers b fi re ia k j we T r r i tf te aes ee J z f T F i ri s k Ea eee se a fant lg a a r J A Sa a E Ha i ap 3 oe i it ve Feit EPI yg w a i k a i ai farts Cii sae Le ae A i i r UDE j a E 7 i F i ATT n a E i i i 4 Fa me x KAN e a r gt F Si ey eee i E id F i Radarsat Standard Beam image of Cook Inlet 5 Ma ee i i a E 51 ASF MapReady User Manual This Radarsat image of the Cook Inlet Alaska contains some fairly steep topography that requires terrain correction A considerable part of the image is covered with water that we want to mask out in the process General Calibration External Polarimetry Terrain Correction Geocode Export DEM File E data alos cook_inlet_dem img Browse p Fill DEM holes with interpolated values Refine Geolocation Only Apply Terrain Correction v Apply a user mask Automatically Mask Mask from File Mask File Browse Perform co registration FFT Matching Specify Pixel Size meters Also apply radiometric Terrain Correction
92. like the SAR data to be kept then use 1 as the fill value Se SF SF OSE fill value 0 Normally during terrain correction only geometric terrain is t applied This option will also turn on radiometric terrain corrections This option is still experimental The correction adjusts the values to account for the actual incidence angle using the DEM instead of the estimated incidence angle using the Earth as ellipsoid used during processing do radiometric 0 If your DEM has a number of holes in it this can cause streaking t im thse terrain Corrected produce THiS optzon will attempt to replace DEM holes with interpolated values smooth dem holes OQ If the DEM has a pixel size that is significantly larger a factor of 2 than the SAR image by default the SAR image is downsampled to a pixel size half that of the DEM With this option set to 1 no resampling of this type will be done However the quality of the terrain corrected product is still limited by the resolution of the DEM By default this option is off 0 Se OSE OSE SHE H H no resampling 0 Even if you don t want to change the image via terrain correction you may still wish to use the DEM to refine the geolocation of the SAR image If this flag is set terrain correction is NOT performed refine geolocation only 0 Layover shadow regions can either be left black resulting in better image statistics in the remainder of
93. ll generate an Terrain correction section where you can define further parameters terrain correction 1 The calibration flag indicates whether the calibration parameters are t applied to the data through ast calibrace qL for running it 0 Lor leaving out the calibration step Running asf_mapready with the create option and the geocoding flag Switched on will generate a Calibration section where you can define further parameters Calibration 1 The geocoding flag indicates whether the data needs to be run through asf_geocode 1 for running it 0 for leaving out the geocoding step Running asf_mapready with the create option and the geocoding flag switched on will generate an Geocoding section where you can define further parameters geocoding 1 The export flag indicates whether the data needs to be run through T Aer texport 1 for ru unning ity 0 for leaving Out the export step Running asf_mapready with the create option and the export flag Switched on will generate an Export section where you can define further parameters export 1 The mosaic flag indicates whether the data needs to be run through asf_mosaic 1 for running it O for leaving out the export step Running asf_convert with the create option and the mosaic flag Switched on will generate a Mosaic section where you can define further parameters Se SF OSE H H mosaic 0 The default v
94. mat In this format the image files are flat generic binary files without any headers and have the extension img Associated with each img file is a human readable text metadata file The metadata files have a meta file extension 2 2 Calibration A SAR processor is calibrated when the coefficients required for accurate radiometry have been determined for it An image is calibrated when those coefficients have been applied to it Calibrating a SAR image is the process of converting a linear amplitude image into a radiometrically calibrated power image The input image is in units of digital numbers DNs whereas the output image is in units of Bo yo Or So which is the ratio of the power that comes back from a By patch of ground to the power sent to the patch of ground The application requirements will help determine which of these calibration units to choose Scientists are generally interested in quantitative measures that are reference to the ground i e they would work with oo values For calibration purposes yo values are preferred because they are equally spaced Finally system design engineers would choose By values because these values are independent from the terrain covered g o a DN a N Ya gt cos 8 Ba 07 o sin The radar backscatter coefficients oo yo and Bo are calculated using the equations above The digital numbers DN are the original pixel values The noise
95. mat can be handled by the majority of image processing software packages 3 5 3 Converting ALOS PALSAR data into GeoTIFF format PALSAR is the L band SAR instrument on board the ALOS satellite It operates in a variety of modes with different polarizations single dual and quad pol and look angles For this example we demonstrate the conversion of a quad pol image into GeoTlFF format 47 ASF MapReady User Manual General Calibration External Polarimetry Terrain Correction Geocode Export Export Format GeoTIFF tif gt Y Output data in byte format instead of floating point Sample mapping method Statistical 2 Sigma C Export All Bands as Separate Images C Export RGB Image according to Polarimetric selection Export Multiple Bands in a Single RGB Image f User Defined C True Color False Color Red Band HH Green Band HV Blue Band VV In this case we chose both horizontal and vertical polarizations as well as one of the cross polarizations for the RGB composite VH band 48 ASF MapReady User Manual lt is apparent that in this image the HH band provides much more contrast than the VV band With this kind of difference in the opposite polarizations it is to be expected that the cross polarized bands would show up very dark When compared with each other both cross polarized bands look very similar Interpreting polarimetric data is not straight forward There are a few
96. mplitude derived from the DEM is NOT used for matching with the slant range SAR image The offset is specified in meters range offset 0 000000 This parameter sets the offset in azimuth direction in case the simulated amplitude derived from the DEM is NOT used for matching with the slant range SAR image The offset is specified in meters azimuth offset 0 000000 The DEM that is provided to asf_terrcorr is generally in ground range and is converted to slant range as part of the coregistration procedure After coregistration you can use either the original ground range DEM or the slant range DEM to do the actual terrain correction By default the slant range DEM is used specifying use gr dem 1 will use the ground range DEM The choice only makes a Significant difference in regions of layover both produce similar results in areas without layover Using the slant range DEM results in more aggressive interpolations which sometimes results in streaky looking layover regions whereas using the ground range DEM preserves more structure within the layover regions but can look worse if the coregistration is off in those areas H HHHH H H H H H H G u D Q Bb Q D 3 Il This option causes terrain correction to try to use the DEM to refine the geolocation of the SAR image before terrain correcting but if this fails then proceed with terrain correction anyway using offsets of zero I e assume the geolocation o
97. n output image that is the union of all listed input images Where the input images overlap the pixel in the image listed earlier on the command line is chosen At least two input files are required You may list as many input files as desired however extremely large output files will take some time to process All input files must be geocoded to the same projection with the same projection parameters and the same pixel size deskew Deskew is used by terrain correction to square up an image for co registration once it has been converted to slant range It uses the squint angle of an image along with the 100 ASF MapReady User Manual look angle to determine the amount of parallelogram shift skew that has been introduced in an image due to the Doppler centroid chosen during image processing It then remaps the image using bilinear interpolation to remove this diffimage Diffimage is an image analysis tool for comparing two images The tool calculates image statistics within each input image and calculates the peak signal to noise PSNR between the two images It also verifies any shifts between the two images The image Statistics and shifts are the basis for determining whether the images are different or not diffmeta Diffmeta is analysis tool for comparing the metadata of two data sets The tool verifies that the individual metadata files have valid entries for parameters that are required for the processing of the data
98. ndesirable effect the ground scatterers are the only contributions of interest Turning this option on will attempt to correct the data for Faraday rotation The method used to apply the correction requires quad pol SLC data Perform Faraday Rotation Correction The correction is done by estimating the rotation angle at each pixel and then applying the correction using a smoothed rotation angle or the average of all the Faraday Correction Threshold degrees rotation e Use local average rotation angles Use global average rotation angle Using the global average rotation angle for correcting the Faraday rotation is the default The calculation of the local average rotation angle requires running a smoothing filter for the averaging This operation needs considerable processing time The user can define a threshold so that Faraday rotation is only corrected for when it exceeds this user defined threshold 3 1 5 Terrain Correction Tab The use of digital elevation models DEMs is optional However a DEM can be used to improve the SAR data in two different ways The most important improvement is the correction of distortions caused by the SAR geometry also referred to as terrain correction Note that in very flat areas the regular terrain correction procedures may not work very well In this case the user may want to consider only refining the geolocation of the image The second improvement is in the radiometry of slopes
99. nditions or to terrain which is more difficult to match such as very low topographical detail especially when combined with speckle This approach works well for water bodies at sea level Alternatively a user defined mask file assumed to be in ASF internal format can be used The description for how to generate a mask file within a GIS environment can be found in the How to guide Generating a mask for terrain correction 23 ASF MapReady User Manual The accuracy of the data geolocation mainly depends on the quality of the orbit information Some legacy data have issues in case of JERS data pretty severe issues with that while confidence in the geolocation for data from more recently launched satellites such ALOS Palsar is generally high In order to improve the geolocation of the processed data we can use a matching technique based on Fast Fourier Transforms FFTs For this step a simulated SAR image is derived from the DEM and matched with the real image used in the processed The FFI matching is used to determine the offsets in azimuth and range These offsets are then iteratively applied until the solution converges to offsets within one pixel in both directions Currently the FFT matching for ALOS Palsar level 1 1 data is entirely switched off Furthermore the results for low relief areas should be taken with caution With limited topography around the simulated SAR image lacks features that the algorithm is able to match The numbe
100. nerubedaneabecuyecsbeiunerebecasuessetsesed 36 34 OMNI SS CU ON ce ace cae EE 40 OA FOOTE OUNONS wecesed se tetede E sere asad ace dasie a 40 SA2 ole ola ee ee E eee ee Teo en ete en irs 41 29 HEXAIMPIC Si ttacsintntaind nensaiadesicotetstnaedosaiareissicaei si aiaaleniainte ccaiat de niainter orn aiack 42 3 5 1 Converting optical ALOS AVNIR data into GeoTIFF format 42 3 5 2 Converting optical ALOS PRISM data into GeoTIFF format 46 3 5 3 Converting ALOS PALSAR data into GeoTIFF format 008 47 3 5 4 Terrain correcting standard beam RADARSAT imagery 00008 51 3 5 5 Using the Cloude Pottier Polarimetric decomposition ccc cceeees 56 3 5 6 Correcting Palsar for Faraday Rotation cccccccccssecesseeeeeeeeseeeeeees 60 3 5 7 Using Pauli decomposition with UAVSAR data ccceccseeeeeeeeeeeees 61 4 The interface between MapReady and PoISARPYLO scccccseeeeeeeeeeeeeeeesaeeeenaaes 63 De AS WICW osaa 66 Silt MeV Coir WON eae ceeee eee cecaue eect eaecae aa autent cee eens densities eeetenee auc 66 92 AG Ac FE VIOW eee en ec ete eee ee eee te Pern ret Pen one MORE Te O ROe VRE INT EOP PUT ee NER onary 66 O21 IBASIG MOUSSE USAGE isan nsen diosa djeny Mein sc ines 67 922 UNIAN OU ONNS tte sects enptbelnph htwg hsehd nddhatemanaghdes 68 5 2 3 Other Useful Keyboard COMMANGAG cccceeceeseeeeeseeeeseeeeesseeeesaaeees 70
101. nes as the input and the same number of samples The Pauli Decomposition The Pauli Decomposition is calculated from the input data using the following formulas e Red HH VV even bounce e Green HV VH rotated dihedral e Blue HH VV odd bounce Using the Pauli decomposition to visualize the data allows one to see the dominant scattering mechanisms in different areas of the scene For example areas with buildings where the even bounce return will dominate will look reddish The Sinclair Decomposition The Sinclair Decomposition is a simple decomposition that combines all four polarizations into a single RGB image in a simple way that doesn t require complex data The green channel is the average of the cross polarization terms which theoretically are equal but may not be due to noise etc This means that the Sinclair decomposition doesn t require SLC data it can be done with Level 1 5 quad pol data whereas the other decompositions require SLC data Level 1 1 Polarimetric decompositions added to MapReady in future versions will likely require SLC data as well Cloude Pottier Classification The Cloude Pottier classification scheme produces output with the data categorized into either 8 or 16 classes The classification is based on three parameters which can be calculated from the 4 band complex data at each pixel These parameters are calculated from the coherence matrix which is calculated for each pixel These p
102. ng the individual image files the bands in the ASF internal format in a band sequential form in a single file In this example the image in the Bahamas was ordered in the 1B2G format i e geocoded in this case to UTM True color RGB composite 43 ASF MapReady User Manual General Calibration External Polarimetry Terain Correction Geocode Export Export Format GeoTIFF tif Output data in byte format instead of floating point Sample mapping method Statistical Sigma C Export All Bands as Separate Images O Export RGB Image according to Polarimetric selection Export Multiple Bands in a Single RGB Image C User Defined True Color C False Color Red Band 3B 0 T Green Band 2 Blue Band ao o kil When exporting the data the data to GeoTIFF there are two standard options to consider The true color option will combine the three visible bands 3 2 and 1 into a true color RGB composite General Calibration External Polanmetny teram Corecton Geocode Export Export Format GeoTIFF tif Output data in byte format instead of floating point Sample mapping method Statistical 2 Sigma Export All Bands as Separate Images 0 Export RGB Image according to Polarimetric selection Export Multiple Bands in a Single RGB Image C User Defined C True Color False Color Red Band p Green Band E y Blue Band 2 44 ASF MapReady User Manual Alternatively the data
103. nmetyy leram Gorecton Geocode Export External Program Slant To Ground gt Convert the image to ground range The pixel size is in the range direction General Calibration External Palannmetny Teram Corectan f Geocode Export External Program Smooth Performs kernel averaging The kernel size should be an odd integer Kernel Size 17 ASF MapReady User Manual General Calibration External Polarimetry Verein arectan Geocode Export External Program Trim Cuts out a portion of the image with the specified width and height in pixels and the given top left corner If the specified region extends outside the image zeros are added Height P Width Fs Start Line 2 Start Sample General Calibration External Polanmety Teram Gorecton Geocode Export External Program Map Grid r Replaces the satellite image with a mapping grid to study distortions Grid count 3 1 4 Polarimetry Tab When processing complex quad pol data PALSAR Level 1 1 several different visualizations are available These polarimetric Decompositions take the four different bands of complex data HH HV VH and VV and mathematically combine them to produce three bands of real valued data which can be directly mapped to RGB and displayed The mappings attempt to highlight the ways in which the various terrain features respond to the polarized signal data from the satellite General Cal
104. ocoding All pixels at this particular height will have no geometric distortions in the resulting geocoded image This assumes that no terrain correction is applied to the data if terrain correction has been applied the average height value is ignored since the DEM provides all height information Another 26 ASF MapReady User Manual option that may be selected is the definition of a pixel size for the geocoded output image Six datums and one reference spheroid Hughes shown on the left can NAD27 be selected from the Datum drop down list as the reference frame The NAD83 most commonly used one is WGS84 which is the default Note that if you HUGHES select Hughes that exporting to a GeoTIFF will result in a spatial ITRF97 reference with an undetermined datum Although this is correct EDSO according to the European Petroleum Survey Group EPSG database SAD69 not all GIS software packages will recognize this type of definition and may have trouble recognizing the map projection definition Also note that the Hughes datum is generally not commonly utilized except in certain polar stereographic SSM I datasets North and South Pole data by the National Snow amp Ice Data Center NSIDC None of the projections defined by MapReady use the Hughes datum You can get a Polar Stereo North projection that uses the Hughes datum instead of the usual WGS84 by selecting the predefined projection Polar Stereo North and then changing to U
105. offset N is a function of range The noise scale factor a and linear conversion factor a are ASF MapReady User Manual determined during the calibration of the processor The values resulting from the equations above are in power scale In order to convert them into dB values the following relationship is utilized dB 10 log power scale Calibrated images generally use the logarithmic dB scale When image statistics are calculated for calibrated imagery special attention needs to be given to the logarithmic nature of the values In order to correctly determine the mean value of any part of the image for example the calculation has to be based on power scale values The mean power scale value can then be converted back into the logarithmic scale to correctly represent dB values 2 3 Terrain correction SAR images are acquired in a side looking geometry This leads to a number of distortions in the imagery Example Note how the oun mT AK 3 appear to lean left towards the satellite path This is known as foreshortening in SAR images see below This image also contains layover and shadowing as well ASF MapReady User Manual Sensor Image plane A C Foreshortening The layover effect represents the extreme case of foreshortening The signal backscattered from the top of the mountain is actually received earlier than the signal from the bottom i e the fore slope is reversed The pixel information from var
106. on s text area and finally the Convert Coordinates button performs the projection Each line should contain a single coordinate pair to be converted The coordinate pair can contain two or three values the third is the height value and if it is omitted the projection is calculated with a height of 0 The source and target projections are specified as on the Geocode Tab in MapReady You may either select a predefined projection and you may define your own projections as discussed in the MapReady section on geocoding or enter your own projection parameters When using the UTM projection if the Zone value is left blank the first coordinate that is projected will determine which zone is used for the remainder of the coordinates This value is then placed into the Zone textbox The Read Coordinates File and Save Coordinates File buttons load and save ASCII text files of coordinates This might be used if you wish to take the projected coordinates and load them into a spreadsheet application such as Excel 19 ASF MapReady User Manual 7 Using MapReady from the command line asf_mapready This program can ingest ASF and other formats of data terrain correct it geocode it and export it to a variety of imagery formats The user is able to control how asf_mapready dictates the processing flow by creating and or editing a configuration file which is fed into asf_mapready when it is called It provides all of the functionalit
107. on deletes a file from the list of processed files This is handy for example when the output files are not going to be reprocessed and you dont need to view the log metadata output or the output in Google Earth All selected files are removed a The View log button allows the user to display the log file once a data set has been processed The log file contains the feedback from the individual functions called as part of the processing flow The log file is the single most useful piece The Prepare to Re Process button moves the image back into the processing queue This feature is useful when image had apparently not been processed with the intended processing parameters 36 ASF MapReady User Manual of information for troubleshooting problems as it contains the error messages that the tool issues in case the processing needs to be aborted Log ioj x Processing Log For E datal alos LED 4layv2a0372683110 01626_U Running convert with configuration file E datalalos ALAVZa0s 2S3110 Ol1B2G U 6 Feb z z007 _11 07 397ALAVZA037283 Importing E datayalos ALAVZ4037293110 01B26 U Data format CEOS File E idatayalos ING Ol ALAVEADS7EZS3110 O1B26 U Input data type level two data Qutput data type geoacoded amplitude image Input band O1 Processed S480 of 8480 lines File E i data yalos IMNG O2 ALAVeans72s3110 O1BeG U Input data type level two data Output data type geacoded amplitude image Inpu
108. on the platform satellite that dual pol and quad pol products generally have lower resolution than single pol products 2 6 Configuration file The MapReady tool has a large number of options and parameters that define the exact processing flow to be run In order to keep track of the parameters in an organized fashion they are stored in a configuration file The graphical user interface version of the tool produces this configuration file from user selected settings on the fly and then executes all of the selected processing steps based on that file For simplicity s sake the configuration file produced by the graphical user interface is of the same type as the one required to run the command line tool For throughput reasons a batch mode is available that allows users to run large quantities of data files through the system with minimal user input All essential options can be stored in a default values file that is used to process all files in the batch file list using the same set of parameters other than the input and output file names The defaults settings file is in addition to the configuration file Setting these files up for use with the command line tool is described later in the Running ast_mapready in batch mode section and this section should be understood clearly before using the default settings file so you understand which overrides the other 2 7 Temporary directories MapReady provides the user with the capability o
109. parameters to an amplitude image The radiometric sigma gamma or beta values are either in linear power scale or logarithmic dB The tool has a wh_scale option that scales the resulting image to byte values using a formula developed at Woods Hole Research Center cal DN byte cal DN 31 0 15 1 95 ASF MapReady User Manual asf_calpol The asf_calpol program decomposes SLC quad pol data into data required to build some common polarimetric decompositions It has a number of options Without the c pauli or sinclair options the output is a nine band image band 0 Amplitude HH band 1 HH VV even bounce Pauli red band 2 2 HV rotated dihedral Pauli green band 3 HH VV odd bounce Pauli blue band 4 Entropy band 5 Anisotropy band 6 Alpha band 7 HH Sinclair red band 8 HV VH 2 Sinclair green band 9 VV Sinclair blue When used with the c option the output is a two band image band 0 Amplitude HH band 1 Classification band When used with the pauli option the output is a four band image band 0 Amplitude HH band 1 HH VV even bounce Pauli red band 2 2 HV rotated dihedral Pauli green band 3 HH VV odd bounce Pauli blue When used with the sinclair option the output is a three band image band 0 HH Sinclair red band 1 HV VH 2 Sinclair green band 2 VV Sinclair blue When used with the freeman option the output is a three band image with the three Freeman
110. r more information on the Cloude Pottier decomposition Cloude S R and Pottier E 1997 An Entropy Based Classification Scheme for Land Applications of Polarimetric SAR EEE Transactions on Geoscience and Remote Sensing 35 1 68 78 Freeman Durden The Freeman Durden decomposition is a model based approach it attempts to fit the combination of three simple scattering mechanisms to the polarimetric data These mechanisms are i even or double bounce scatter from a pair of orthogonal surfaces with different dielectric constants ii canopy scatter from a cloud of randomly oriented dipoles and iii Bragg scatter from a moderately rough surface These three components are assigned to the three color channels during export the double bounce component i is assigned to the Red channel the canopy component ii is assigned to the Green channel and the rough surface component lil is assigned to the Blue channel The results look similar to the Pauli decomposition For more information on the Freeman Durden decomposition 20 ASF MapReady User Manual Freeman A and Durden S 1998 A Three Component Scattering Model for Polarimetric SAR Data EEE Transactions on Geoscience and Remote Sensing 36 3 963 973 Faraday Rotation Atmospheric conditions are another condition which can affect the backscatter values in addition to the scatterers on the ground This effect is called Faraday rotation and usually this is an u
111. r of matches with low confidence levels that even decrease the geolocation accuracy significantly increases in flat areas The selection of FFT matching should be carefully evaluated and done on a case by case basis The terrain correction itself is always a function of the quality of the DEM used for the correction The terrain correction corrects the distortions in the SAR image using the height information in the DEM The terrain correction is performed using the original pixel of the input data This behavior can be overridden by specifying the otherwise optional pixel size The pixel size option in the Geocoding tab described below is more appropriate if you are attempting to size the final image product the pixel size value specified here should be selected based on the pixel size of the DEM Apart from the geometric correction performed by the terrain correction the image can be also corrected for its radiometry The correction adjusts the brightness of the slopes facing the sensor during the acquisition For more details refer to the terrain correction section By default layover and shadow regions in the terrain corrected image are filled with interpolated values By deselecting this option the algorithm fills these data holes with Zeros The layover shadow masks as well as the clipped DEM both generated in the terrain correction process can be saved for further analysis These products are very specific to this process and do not f
112. r scale into dB see checkmark above 7 Apply ERS2 Gain Correction ta ERSZ data Also on the import tab is the Apply ERS2 Gain Correction checkbox greyed out until radiometric calibration other than Amplitude is selected The ERS2 satellite has a known gain loss problem that MapReady will attempt to correct by applying a scale correction factor uniformly to all pixels in the image The correction is dependent on the date and is only applied to calibrated data i e everything but amplitude If you are not processing ERS2 data checking or unchecking this option has no effect Contact the European Space Agency hito www esa int for more information on the ERS missions ASF MapReady User Manual 3 1 3 External Tab The external tab contains a number of external programs that canbe uns 1e gt ant plugged into the regular processing flow This plug in architecture is 2 Ground open so users can generate their own plug ins and use them within ne MapReady More details on how to create a plug in can be found in nr How to guide Creating plug ins for the External tab Trim Map Grid The following plug ins have been defined with their respective parameters General Calibration External Polarirnetny Teeth Gorrection Geocode Export External Program Ground To Slant gt Convert the image to slant range The pixel size is in the range direction Pixel Size General Calibration External Pola
113. r that step s processing Note that if you are importing data that is already in ASF Internal Format that while the import conversion step is not necessary the import checkmark will still stay set and greyed out so you cannot change it The general tab also contains the Keep E E tle Intermediate Files options The processing flow creates a number of intermediate results for the various processing steps For troubleshooting purposes or further analysis those intermediate results can be kept Examples include the imported data layover and shadow masks automatically generated imported versions of your DEM clipped DEMs etc By saving the intermediate products you can often troubleshoot your processing if you did not achieve your desired results Temporarily keep intermediate files Keep intermediates The Temporarily keep intermediate files option the default means that these intermediates are kept until you exit MapReady or remove the processed product from the Completed Files section Keeping these intermediates around after processing is done allows you to look at these files with the View Intermediates option in the Completed Files section More information is available in the description of the Right click context menu of the completed files list Not all intermediate products are available in this menu those that aren t can be viewed with ASF View by selecting the file within ASF View If you select th
114. reduction_factor and transparency The reduction factor is multiplied by the pixel size to reduce the size of the image default value 8 The transparency value defines the level of transparency of the overlay value range of 0 to 100 with default value of 0 There are two ways of generating color overlays For single band images a color look up table LUT can be applied with the co ormap option For this purpose the user can provide his own LUTs or take advantage of the predefined LUTs in the share directory For multi band imagery the rgb option allows the user to refine bands for the red green and blue channels There are three types of KML overlays that are specifically generated for PolSARPro files segmentation decomposition and parameter They are defined with po sarpro option asf_mapready The asf_mapready program is command line version of what is behind the MapReady GUI It allows the user to run larger amounts of data without any manual interaction The only input the tool needs is a configuration file that defines all the processing parameters It is described in more detail in a previous section asf_proj2proj This is a command line interface to the ASF Projection Coordinate Converter To use it you must have the source and target projections defined in projection files though one of them may be the latlon pseudo projection Projection files are generated by MapReady during geocoding if you ve saved your t
115. rt the parameter blocks specified in the General block and will remove those that are not In the example above re running asf_mapready will add Import Geocoding and Export blocks to the configuration file and will remove the Terrain correction block if it existed asf_mapready create R153253303G63S007 cfg 5 Edit the parameters within each processing block 6 Iterate the steps above if you wish to make changes i e edit the configuration file and re execute asf_mapready with the create flag until everything in the configuration file is correct 7 Execute asf_mapready with your finished configuration file asf_mapready R153253303G3S007 cfg 8 Correct any issues which occur during the execution of asf_mapready i e errors in settings or data locations incorrect or whatever may occur Warnings that appear are informational and may or may not require action on your part while errors that occur require you to correct something before the processing can complete As mentioned in the above sequence more experienced users can switch the explanatory comments part of the configuration file output off by setting the short configuration file parameter to 1 File Basenames lt is obvious that the input and output files need to be known To specify an input file name to asf_mapready you just enter the basename as the following examples show Note that the basename is either the file name without a file extension or as in the case
116. s Data Format UAVSAR Annotation File E data uavsar Bigls _05901_12003 004 120108_L090_Cx O1 ann UAVSAR POLSAR Product Types All Types T MLC PUAVSAR InSAR Product Types All Types AMP UNW COR AMP GRD 7 INT GRD 7 UNW_GRD COR_GRD HGT_GRD X Cancel OK For UAVSAR data the annotation file contains the information what kind of data is theoretically available for processing The interface determines which files actually in the directory where the annotation file is stored Based on this information the user can select which data is processed a Add File to Process Data Format PolSARPro Image Data Type Polarimetric segmentation PolSARPro Data File Select Colormap None The import of files generated by PolISARPro software requires additional information that the user to define in the PolISARPro specific file selection window MapReady defines four different image data type for PoISARPro generated data sets 31 ASF MapReady User Manual Polarimetric segmentation Polarimetric decomposition Polarimetric parameter Polarimetric matrix There are a number of predefined colormaps that can be attached None to PolSARPro segmentations These colormaps do not apply to ern wo Means any of the other image data types H Alpha Lambda_27 H_4 Alpha 9 After selecting the PolISARPro Data File or a PolSARPro Matrix Supervised_Wishart_16 file in case of polarimetric matrices MapR
117. s a wrapper for this program for the special case where only one image is being mosaicked refine_geolocation Part of the terrain correction process Is to eliminate any offsets between the SAR image and a SAR image that is simulated from a DEM by adjusting the SAR image s metadata With an accurate DEM this can improve the geolocation of the SAR image to sub pixel accuracy The refine_geolocation program performs only this part of the terrain correction process improving the geolocation of the image but not actually applying the terrain correction This is used by MapReady and asf_mapready to do the refine geolocation only option of terrain correction resample This program provides simple resampling functionality allowing one to convert an image with one pixel size to another This gets used by MapReady and asf_mapready a number of different times primarily in the terrain correction processing when getting the SAR image and simulated SAR images to the same pixel size shift_geolocation This program enables users to adjust the geolocation of an image manually It adjusts the time_shift and slant_shift values in the metadata to produce geolocations shifted by the given amounts The x shift and y shift values are in units of pixels or meters If the image is already geocoded then the startX and startY values are adjusted by the specified amounts instead of the time and slant shift values This program could be used
118. s also been geocoded to our chosen projection and exported to our chosen format During export the look up table layover_mask lut is applied which maps each of the above to a different color User masked values e g water when applying automatic masking are coded in blue Layover regions are depicted in green regions of shadow are red Invalid data which include areas of no data during the terrain correction as well 54 ASF MapReady User Manual as background fill resulting from geocoding the mask are displayed in dark grey All other valid data is indicated in black In this case we have overlaid the mask on top of the terrain corrected image Layover mask overlaid on the terrain corrected image 55 ASF MapReady User Manual 3 5 5 Using the Cloude Pottier Polarimetric decomposition The Cloude Pottier polarimetric decomposition is a classification scheme where pixels are classified according to the values of three calculated parameters In this example we will process a PALSAR Level 1 1 quad pol dataset with the 8 classes Cloude Pottier Decomposition The dataset is of the Washington DC area and the HH channel is shown above 56 ASF MapReady User Manual General Calibra tion Externe Polarimetry Teram Corection Geocode Export ff Perform a Polarimetric Decomposition Pauli Decomposition AV VH HH VV Sinclair Decomposition HV VHi 2 WW Cloude Pottier classification with amp cate
119. s to the image location on the Google Earth globe and for most UTM projected images displays an overlay which illustrates the image boundaries 38 ASF MapReady User Manual Right click context menu Remove Queue for Reprocessing The functionality of the completed files section menu buttons is ee also available as a right mouse click context menu as shown ee a een re on the right The menu can only be invoked when a file is Display ASF Metadata selected from the file list though if only one file is there it will be view Output selected automatically view With Google Earth tm In addition to the menu options which duplicate the functionality of the toolbar buttons there is also a View Intermediates menu If you have chosen to Temporarily keep intermediate files or Keep intermediate files selected in the General Tab of the settings then a few selected intermediates files can be loaded in to ASF View using this menu Intermediate files which are not available or do not apply to the selected dataset are grayed out In the example shown to the right only terrain correction was performed so only products pertaining to Display ASF Metadata view Clipped DEM terrain correction were produced In this e Sutput Wan Siit leal Sai lets case the clipped DEM was not View With Google Earthitm et Faraday Potation generated since we did not select Save ee Ua el Clipped DEM We did select Save Layover Shadow
120. seeeeseeeeseeeeseeeseeeeaaes 117 ASF MapReady User Manual 1 Introduction This manual provides a complete overview of the conversion from operationally produced synthetic aperture radar SAR and optical data to a variety of user friendly formats ready for additional processing viewing or being utilized in GIS software It presents the theoretical background for the formats corrections and processing steps in the processing flow This manual describes the functionality of the graphical user interface GUI and command line interface tools provided in the MapReady remote sensing software package Examples of completed runs are provided A number of exercises are provided explain how the MapReady software can be utilized for a variety of different applications This software and documentation was produced by the Engineering group at the Alaska Satellite Facility part of the Geophysical Institute at the University of Alaska Fairbanks 2 General background This section provides some background information to allow the user to make the most effective use of the MapReady software 2 1 Data formats After processing the analog SAR signal to binary SAR signal data the data is called level zero LO data in SKY telemetry format STF The level zero data covers a certain area on the ground in the form of a swath The length of the swath depends on the amount of data originally collected during the actual acquisition The size of the files var
121. ser Defined This will leave the projection parameters for the Polar Stereo North projection central meridian 150 and first standard parallel 70 and you may then change the datum to Hughes As part of the transformation from the SAR geometry into the map Nearest neighbor projected space pixels need to be resampled using an Bilinear interpolation approach The list on the right offers three different Bicubic methods The nearest neighbor approach is the fastest of these techniques but also regularly introduces unwanted artifacts The bilinear interpolation scheme considers four neighboring pixel values and typically leads to satisfactory results and is therefore the default setting Bicubic interpolation is even more accurate but is also computationally the most intensive of the three 3 1 7 Export Tab In order to use the data in external software packages the user might want to convert the images to a more common format This processing is optional however selected by default lf export processing is unselected on the General Tab then no export will occur and any data that has been processed will remain in ASF Internal Format see Import Tab section above Also if export to a graphics file format is selected then the metadata meta file that applied to the ASF Internal Format file set will remain after the export but the image data img file will be gone unless you elected to save intermediate files see General Tab section
122. ser may select exporting each band or channel to a separate file i e each color optical or polarization SAR channel or to a color file if Supported by the selected graphics file type In addition to being able to manually select which color band individual channels are mapped to for polarimetric data several predefined settings are available as selected on the Polarimetry tab lf you have selected a polarimetric decomposition you will not be able to select RGB channel assignments the only option available is Export Image According to Polarimetric Selection The exception to this is the Entropy Anisotropy Alpha decomposition Cloude Pottier without classification when you may assign each of the classification parameters to an RGB channel or export each as a separate grayscale image For optical images you may also select True Color or False Color output types If True Color is selected band 03 will be assigned to the red band 02 to the green band and 01 to the blue band If False Color is selected then band 04 near IR will be assigned to the red band 03 to the green band and 02 to the blue band Additionally whenever True Color or False Color is selected each color band is individually contrast expanded using a 2 sigma contrast expansion derived from each band s individual statistics 3 2 Input Files While the tabs section defines the steps parameters and options of the processing flow the files section control the d
123. t e Converting it into various graphical file formats The GUI consists of six areas tabs that allow the user to set up monitor and execute the conversion processing flow The functionality of these six areas is described in this section of the manual in more detail The Settings section and the two Files sections contain expand collapse O buttons which hide and show each section 3 1 Settings This area consists of one general and six processing tabs that define all the parameters used in the conversion process seven tabs in all generally clicked and options set in left to right order 3 1 1 General The General tab controls which of the six Select Processing Steps processing steps take place Importing Polarimetry Terrain Correction Geocoding I Import Data required 4 and Exporting There is one additional tab Run External Program located between Import Settings and Polarimetry to allow running a plug in tool after import but before other processing Polarimetry Conky For quad pol SLE data Terrain Correct with Digital Elevation Model Geocode to a Map Projection The Import processing step is required and F Export to a Graphics File Format therefore cannot be deselected however the other steps are optional By default only Import and Export are turned on Checking unchecking each step s checkbox will turn on or off the tab that contains the ASF MapReady User Manual settings fo
124. t added and Escape clears the entire path Arrow Keys Move crosshair 1x To fine tune the positioning of selected points use the arrow keys By default the most recently positioned point is moved Using ctrl and or shift with the arrow key will move the crosshair by a larger amount ctrl arrow 10 pixels shift arrow 25 pixels ctrl shift arrow 250 pixels Tab Toggle which crosshair is moved The tab key will change the point that is moved when the arrow keys are used To illustrate how defining polygons works we will measure the circumference of the field in the image to the right We start by left clicking on the top left corner If we miss the point we can use the arrow keys to fine tune the location lf necessary we could zoom in to ensure that weve got the actual corner 68 ASF MapReady User Manual image shown to the right Now tab will move the red crosshair along the selected points marking which is going to be affected when the arrow keys are used lf Backspace is used the most recently added point is removed We dont need to add the final edge of the polygon if we are only interested in the area since the area calculation always implicitly Next ctrl left click on the top right corner of the field After this the arrow keys will move the red crosshair Using tab we can switch between which crosshair is affected by the arrow keys Note that when the green crosshair
125. t band O02 Processed S460 of 8480 lines File E i data yalos IMNG O3 ALAVeans72o3110 O1Be6G U Input data type level two data Qubpub data type geacoded amplitude image Input band OF Processed 5450 of 6450 lines File E datayalos ING O4 ALAVEA0S7e2S3110 O1B26 U Input data type level two data Qubpuk data type geocoded amplitude image Input band oO4 Processed 2450 of 684580 lines Import complete The Display ASF metadata button opens a text window with the internal ASF metadata The metadata contains a number of structures that provide the essential information to identify describe and process the data It is a very small subset of parameters that are extracted out of the CEOS metadata 37 ASF MapReady User Manual i ASF Metadata Meta Data File E datajalos 4lLav2q037285110 01626 U0 utm meta This file contains the metadata for satellite capture file of the same base name T is likely an unknowm single character value 777 is likely an unknowm string of characters 999999999 is likely an unknown integer value nan is likely an unknotm Beal value HHH amp H meta version lt 00 general Begin parameters generally used in remote sensing name E dataialos ING O4 ALAVea0sressllo OlBeG U File name sensor ALOS Imaging satellite sensor name AVNIR Imaging sensor mode LBZC processor 1777 data type BYTE image data type GEOCODED IMAGE system lil ieee acquisition d
126. t corner Left Click and Drag panning Panning is accomplished by left clicking on the image and holding the mouse button down while dragging the image to the new location scroll Wheel Zoom in out Zooming in out is accomplished using the scroll wheel on the mouse The page up down keys will do the same thing Zooming in to zoom factors smaller than 1 i e when 1 pixel in the image will cover multiple screen pixels is possible though the image will begin to look pixilated No smoothing or filtering is done for zoom levels greater or smaller than one Home Zoom to 1 1 End Fit Image To Window The End key will Zoom out to a zoom level such that the entire image is visible in the main viewing window Home will return to the default 1 1 view 67 ASF MapReady User Manual 5 2 2 Defining Polygons Ctrl Left Click Place secondary crosshair s Holding ctrl while left clicking will place a red crosshair This secondary crosshair can be used to measure distances After placing the secondary crosshair the distance between the two points is displayed in the information section More than one secondary crosshair can be placed This will define a polygon and the total length and the enclosed area of the polygon is displayed in the information section Backspace Remove last citrl clicked point Esc Clear ctrl clicked path Erroneous or badly placed ctrl clicked points can be cleared using Backspace clears the last poin
127. t this is a small L ell not a capital I eye will move the crosshair to the brightest pixel in a 30x30 region centered on the current position of the crosshair Using ctrl l will search in a larger region 800x300 pixels again centered on the crosshair This applies to the active crosshair For example to measure the distance between two corner reflectors we can use this procedure 1 Click near the first corner reflector and press I to move to it 2 Ctrl Click near the second corner reflector and press I again This moves the secondary red crosshair Now the information section displays the distance between the two reflectors 70 ASF MapReady User Manual 5 3 Saving Image Subsets When a polygon has been defined using ctrl click to define a path as described above the Save Subset button in the button toolbar below the full image thumbnail becomes active Clicking this button brings up the Save Subset dialog iol x Subset Information Extent Line 43235 4841 Sample 6795 7375 Qutpuk will be 519x581 Lx5 Format fe ASF Internal C coy Directory F data Browse Filename le 2259029060 1U0l4_aji Data To Save Pixel Values ve Strict Boundary Load Saved Subset A cancel bel Save This allows us to save the selected portion of the image as a separate file in either ASF Internal format an image format or as a CSV file a text file containing the data values in comma s
128. te an output image with square pixel size That can significantly reduce the data volume and the result can be interpreted in a more straightforward way A more refined multilooking can be achieved by using the azimuth look count and range look count options These options allow the definition of any ratio to applied to the data instead the default one For multiband images there is a band option to ingest individual bands GeoTlFF files do not provide any information about the type of data they contain The image_data_type option allows the user to specify the type of data The most useful image data types are amplitude_image phase _image coherence_image 98 ASF MapReady User Manual lut_image elevation dem polarimetric_image image image_layer_stack and mask asf_kml_overlay The asf_kml_overlay tool generates KML overlays from a large variety of ASF internal and PoISARPro files The tool verifies that the data is actually geocoded to one of the map projections supported by the ASF tools In order to ensure a better alignment within Google Earth it is advisable to use a digital elevation model to terrain correct or to refine the geolocation of the input image As a first processing the input image is re projected into the equi rectangular map projection that is internally used by Google Earth The properties of the resulting PNG file are mostly defined by two options
129. tem which is then placed in the output image Since the output pixel will not typically correspond exactly with a single pixel in the input image resampling or interpolating must be performed This utility performs the functionality available on the Geocode tab of MapReady and the Geocode section of asf_mapready asf_import The asf_import tool is used to import data from its original format to the internal format used by the ASF tools MapReady package the SAR Training Processor etc This program must be used on any data before any of the other command line tools can be used with that data The antenna pattern can be applied to SAR data by using the sigma beta or gamma options the antenna calibration coefficients are included in the CEOS metadata Doing so will apply the antenna pattern to the data in the given Bo yo Or oo projection The product will be in the power scale If it is preferred to have the data in the decibel scale the db flag can be used Complex SLC data are can be processed in a variety of ways By default asf_import will generate two bands an amplitude band and a phase band out of every SLC input that it encounters This allows the user to visualize those data sets at any time The complex option leaves the SLC in its original complex form storing it in its real and imaginary part In case the user is not interested in polarimetric processing it is advisable to use the multilook option to genera
130. the image or they may be interpolated over resulting in a nicer looking image Setting this parameter to 1 indicates that these regions should be interpolated over interpolate 1 113 ASF MapReady User Manual The DEM that is provided is clipped to match the scene Normally this clipped DEM is removed along with the other temporary files however if you are interested you can turn this option on set it to 1 which will keep the clipped DEM as well as geocode if you ve elected to geocode and export it if you ve elected to export though the DEM is always exported as floating point data even when you exporting your SAR data as bytes The clipped DEM will be slightly larger than the SAR image usually since a larger region must be clipped to allow for the height variations Se OSE OSE SHE H H SE H save terrcorr dem Q This option determines if a file marking the regions of layover and Shadow should be created along with the output image It is geocoded using the the same parameters as your SAR image and exported as byte data Save terrcorr layover mask 0 This option determines if the simulated image derived from the DEM is used for matching with the SAR image in slant range If you don t trust the quality of the orbital information or want to determine your own offset you want to switch this flag to T no matching 0 This parameter sets the offset in range direction in case the simulated a
131. tion default only Lambert Conformal Conic ene requires the zone number to define the Sure other map projection parameters If the user does not specify a zone hawaii the program automatically determines the zone from the center longitude of the respective image The user can define a different zone as long as the zone is valid for some part of the image north america south america Usa _ contiguous For all other map projections the user can choose from a list of geographical regions for which the required map projection parameters are predefined For the Polar Stereographic projection the choices are limited to the northern or southern hemisphere The remaining map projection offers definitions for a larger 25 ASF MapReady User Manual number of areas as indicated on the left Alternatively a user defined map projection may be defined by selecting the type of map projection and manually entering the appropriate map projection parameters for that type In order to permanently add a user defined map projection a projection file may be created and stored in the projections subdirectory The easiest way to do this is to copy one of the existing map projection definition files proj to a new name and then edit the parameters in the file When doing so it is important to only edit the values to the right of the symbols found within the file else the value parsing may fail Albers Equal Area Conic Area Custom Datum NAD
132. tire rectangular area should be saved When checked the areas outside the selected polygon are left black These two images are examples of saving with Strict Boundary selected left and without Strict Boundary selected right for the region selected above 13 ASF MapReady User Manual Load Saved Subset When this option is checked the newly created file will be immediately loaded by ASF View When unchecked the file is created but you will still have the original data file in ASF View When exporting to CSV if you are on Windows and have Excel installed Excel will be started with the created CSV file loaded 5 4 Toolbar Buttons Google Earth zooms to the image location on the Google Earth globe and displays an overlay for images in the UTM projection which illustrates the image boundaries The Google Earth button functions as it does in MapReady launches The overlay is only available if the data is projected data The Display CEOS metadata button launches the ASF metadata viewer The viewer reads the CEOS leader file a partially binary and partially ASCII file that contains the metadata associated with the binary data More details on the CEOS metadata viewer are available in the MapReady section of this manual The Overlay button allows you to select a shape file or a CSV file to overlay p on top of the image 74 ASF MapReady User Manual 5 5 Information Tabs In the tabbed se
133. ttons The footer consists of three buttons that allow the user to manage the processing of all the files loaded in the files section Process All The Process All button starts the processing of all the files listed in the files section The files are processed are processed with the output directories and naming schemes defined for the individual data sets The list of data sets is processed in the order that they were loaded into the files section ad Process All During processing the terminal window that opens along with MapReady will contain the messages generated during the processing These messages can also be viewed with the View Log option after the file has finished processing lf an image is successfully processed it is moved to the Completed Files section If one or more errors occurred during the processing then it remains in the upper Files section and the Status is set to Error along with a small portion of the actual error message To get the full error information use the View Log option Warning messages generated during processing are also kept in the log if your image result isn t satisfactory check the log to see if any warning messages were generated that might explain why the image didn t produce the result you were expecting Note that when the Process All button is clicked the Settings section is automatically collapsed and the Completed Files section is automatically expanded 4
134. uli decomposition The UAVSAR file ingest interface asks for the UAVSAR annotation file to determine what type of data needs to be ingested polarimetric or interferometric Based on the existence of the individual files in the directory where the annotation file is located the user can select the available product types for the data import C11 element of the UAVSAR covariance matrix The selections for the polarimetric decompositions are identical with any other PolISAR data The only difference is that the decomposition calculation is based on the C3 covariance matrix which is the native format UAVSAR data is stored internally 61 ASF MapReady User Manual Pauli decomposition of UAVSAR data of the Big Island Hawaii The Pauli decomposition allows an initial interpretation of odd bounce blue even bounce red and dihedral rotated 45 green components of the backscatter behavior 62 ASF MapReady User Manual 4 The interface between MapReady and PoISARPro PolISARPro is the most comprehensive open source software for processing PolISAR and PollnSAR data It supports a large variety of space borne and airborne data sources However PolISARPro does not have capabilities to terrain correct and or geocode its results For mitigating this shortcoming we have developed an interface that uses MapReady functionality for this task SS a ee ee i j f l l l l l l l l
135. y height specify pixel size define datum define spheroid via projection file define resampling method define background value force flag via settings file Export GUI output format byte scaling sample mapping method RGB combination predefined list true color false color color look up table indirect map projection parameters specifiy height specify pixel size define datum define spheroid define resampling method define background value force flag config file output format byte scaling sample mapping method RGB combination true color false color color look up table explicit command line Universal Transverse Mercator Polar Stereographic Albers Conic Equal Area Lambert Azimuth Equal Area Lambert Conformal Conic Equidistant Equi rectangular Google Earth Geographic Mercator Sinusoidal EASE grid global SMAP GeoTIFF EASE grid north SMAP GeoTIFF EASE grid south SMAP GeoTIFF command line map projection parameters specifiy height specify pixel size define datum define spheroid define resampling method define background value force flag save mapping function define band ID write projection file with projection parameters command line output format byte scaling sample mapping method RGB combination true color false color color look up table explicit define band ID 120
136. y of the MapReady GUI application from the command line 7 1 Generating a configuration file This basic configuration file contains all general parameters with a detailed explanation about the respective parameter for the novice user In general the process of creating a configuration file and setting it up is as follows 1 Run asf_mapready with the create flag to create a configuration file asf_mapready create R153253303G63S007 cfg 2 Advanced users Edit the configuration file and turn on the short configuration file flag a Find the following line in the configuration file and change the flag s value from 0 to 1 General shee Configuration 116 1 b Re execute asf_mapready with the create flag to recreate the configuration file again but without the extra commenting this time asf_mapready create R153253303G3S007 cfg 3 All users Edit all of the settings in the General block then save the configuration file General input file R125419155G1S014 ancillary file output file R125419155G61S014 derault anput dir default output dir project 0 files 0 import 1 80 ASF MapReady User Manual external 0O polarimetry 0 terrain COrr eccion 0 calibration 0 geocoding 1 export 1 mosaic 0 default values intermediates 0 short configuration file 1 dump envi header 1 tmp dir 4 Re execute asf_mapready with the create flag so asf_mapready will inse
137. zoom 1 0 Lat 59 953 Lon 151 769 general information about the zoom level of the image in the main viewing window and the current geolocation of the mouse cursor whenever available 66 ASF MapReady User Manual 5 2 1 Basic Mouse Usage Left Click Place crosshair The crosshair is the currently selected Information point shown with a small green crosshair Line 4096 0 Sample 4096 0 y Pixel Value 38 000000 gt 1 3 By default it is the center of the image bee Pouecei Gone sits qe Incid 7 7459 Look 24 4273 deg The Information section on the left Slant 891387 6 m Time 7 742 s displays information for the currently E Cle eee epee ree selected point Not all of the information shown is present for all images for example when viewing unprojected images no projection coordinates are displayed images with no geolocation information wont have any latitude longitude values and for non Radar images the incidence look slant range and times values won t be displayed For geocoded data sets additional information about map distortion parameters meridian parallel and areal scale factors as well as angular distortion is provided Right Click Re center view Right clicking in the image will change the view so that the clicked on point becomes the new center point The crosshair is not moved The other way to navigate around in the image is to click on the full image thumbnail in the upper lef

ASF MapReady User Manual - University of Alaska System

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