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DLR GOME Product User Manual

1. Product Wavelength region nm O column 325 0 335 0 NO column 425 0 450 0 BrO column 336 0 351 5 SO column 315 0 326 0 H O column 611 0 700 0 HCHO column 328 5 346 0 OCIO column 365 0 389 0 CHOCHO column 435 0 460 0 Cloud fraction 300 800 PMD p Cloud top height pressure and 758 0 771 0 albedo cloud optical thickness 15 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 16 of 47 4 Processing The Universal Processor for UV VIS Atmospheric Spectrometers UPAS is the core GOME retrieval system at DLR A1 UPAS is a new generation Level 2 system for the processing of operational near real time and off line trace gas and cloud properties products UPAS takes as input the calibrated and geolocated Level 1 radiances from different sensors e g GOME ERS 2 and GOME 2 MetOp and produces total columns of trace gases e g O NO BrO H O SO HCHO and OCIO and cloud properties cloud fraction cloud top albedo and height The UPAS system is based on a scalable client server architecture which makes it possible to run the system with an unlimited number of processing nodes The average UPAS processing time for O NO and cloud retrieval includes 15 on pre processing tasks 15 on DOAS 60 on explicit calls to the radiative transfer model LIDORT for AMF calculations and the
2. Octet Description Allowed Values 1 4 BUFR coded according to the CCITT International Alphabet No 5 BUFR 5 7 Total length of BUFR message in octets including Section 0 0 15000 8 BUFR edition number currently 4 1 4 7 4 Section 1 Identification Section Octet Description RE Values 1 3 Length of section in octets int value BUFR master table zero if standard WMO FM 94 BUFR tables are used provides 0 for BUFR to be used to represent data from other disciplines and with their own versions of master tables and local tables 5 6 Originating centre code table 0 01 031 210 7 8 Originating sub centre 0 9 Update sequence number zero for original BUFR messages incremented for updates 1 10 Bit 1 0 No optional section 1 Optional section included Bits 2 8 set to zero reserved 0 11 Data Category type BUFR Table A 3 12 Data Category sub type defined by local ADP centres 255 13 Local data sub category 206 14 Version number of master tables used currently 2 for WMO FM 94 BUFR tables 11 15 Version number of local tables used to augment the master table in use 0 16 17 Year 2XXX 18 Month 1 12 19 Day 1 31 20 Hour 0 23 21 Minute 0 59 22 Second 0 59 7 5 Section 3 Indicator Section Octet Description allowed Used Values 1 3 Length of section in octets 4 Set to zero reserved 5 6 Number of data subsets 200 7 Bit 1 1 observed data 192 0 other data Bit 2 1 compressed data 0 non compressed data Bit 3 8 s
3. lt 10 Cloud albedo cloud optical thickness CTA COT lt 10 lt 10 NRT and OL products have the same accuracy and precision 20 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 21 0f 47 8 August 2012 5 6 Product Formats The format of the product file is either HDF5 or BUFR A detail description of the HDF5 product format is given in section 6 on page 24 and for the BUFR product in section 7 on page 40 5 7 File Name The file name of a product already contains important information about the dataset including trace gases and sensing time It is built according to the following structure SENSOR _GAS_LV_YYYYMMDDhhmmss_ddd_MISSION _PRO_RV TYPE where e SENSOR denotes the instrument i e GOME e GAS is a separated list of trace gases included in the product The acronyms from the above table are used e g O3 NO2 BrO is a products containing these three trace gases e LV is the product level i e L2 e YYYYMMDD are the year month and day of the first processed ground pixel e hhmmss are the hours minutes and seconds of the UTC time stamp of the first processed ground pixel e ddd is the three digit duration of the product in minutes e MISSION denotes the mission ERS2 METOPA METOPB METOPC e is the five digit orbit number e PRO is the processing
4. look at as all the numbers in a message whether data descriptors or the data themselves are binary integers And that of course leads to the machine independence with BUFR consisting entirely of binary integers any brand of machine can handle BUFR as well as any other Theoretically there is no upper limit to the size of a BUFR message but by convention BUFR messages are restricted to 15000 octets or 120000 bits This limit is to allow an entire BUFR message to be contained within memory of most computers for decoding It is also a limit set by the capabilities of the Global Telecommunications System GTS of the WMO In UPAS the length of a single BUFR message is limited to 200 ground pixels that gives approximately 10Kbytes for storing one message The file contains the information corresponding to a single orbit can contain unlimited number of consecutive BUFR messages 7 2 WMO GTS Bulletin Identifier The BUFR products from the O3M SAF can be accessed using the following identifier Region RTH Country TTAAii CCCC CodeForm 6 OFFENBACH GERMANY IUCX01 EDLR FM 94 XIII 40 DLR Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties Page 41 of 47 DLR GOME PUM 01 Iss Rev 2 E 8 August 2012 7 3 Section 0 Indicator Section
5. mol cm Total vertical column density background corrected VCDCorrected_Error float pixels heights Error on total vertical column density SO2_Flag integer pixels z Flag indexing SO2 calculations see 6 8 4 on page 38 for future use not yet implemented 6 6 4 DETAILED_RESULTS H2O Subgroup Dataset Name Data Type Unit Description ESC_O2 float pixels mol cm effective O2 slant column ESC_O4 float pixels mol cm effective O4 slant column RingCorrectionFactor float pixels RingCorrectionFactor H2O_Flag integer pixels Flag indexing H2O calculations see 6 8 5 on page 38 6 6 5 DETAILED_RESULTS HCHO Subgroup Dataset Name Data Type Unit Description ESCCorrected float pixels mol cm Slant column density background corrected ESCRefSector float pixels mol cm Slant column density for the Pacific Region 160 240 ESCRefSectorEquator float pixels mol cm Slant column density for the Pacific Equator Region VCDO float pixels mol cm A priori vertical column density for the Pacific Region 160 240 from IMAGES model VCDCorrected float pixels mol cm Total vertical column density background corrected HCHO_Flag integer pixels Flag indexing HCHO calculations see 6 8 6 on page 39 6 6 6 DETAILED_RESULTS CHOCHO Subgroup For future use not yet implemented Bee ae DLR GOME PUM 01 Product User Manual for GOME Total Col
6. 0 10028 15 6 NO Nitrogen dioxide 5 10102 44 0 BrO Bromine oxide 9 15656 19 6 SO Sulfur dioxide 8 7446 09 5 H O Water Vapour 1 7732 18 5 HCHO Formaldehyde 7 50 00 0 OCIO Chlorine dioxide 10 10049 04 4 CHOCHO Glyoxal TBD 107 22 2 43 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 44 of 47 8 Using the Products This section contains practical information on using the GOME products As a general advise it is strongly recommended to use only the forward scan pixels and discard the back scan pixels Back scan pixels are not only redundant but they are less accurate than the forward scan pixels due to their larger footprint size The IndexInScan attribute from the GEOLOCATION group in the HDF5 products has values of 0 1 2 for East Nadir West forward scan pixels back scan pixels can be easily filtered out checking that IndexInScan lt 3 Back scan pixels are not included in the BUFR products The H2O entry in the TOTAL_COLUMNS group of the HDF5 products is set to fill value for measurements under cloudy conditions The retrieval values are nevertheless available in the DETAILED_RESULTS group under the VCD entry The BUFR products contain all H O retrievals but it is recommended not to use measurements under cloudy conditions cloud_fraction cloud_top_albedo lt 0 6 The NO2 entry in the TO
7. 6 C 3 gt Wed 4 C gt Thu 4 C Figure 3 GOME 2 MetOp web page at DLR 18 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 19 of 47 8 August 2012 5 Total Column Trace Gases and Cloud Products The level 2 total column products generated with the UPAS system contain retrieved trace gas vertical columns and cloud properties as well as other geophysical parameters corresponding errors on these quantities and a number of additional diagnostics quality flags and intermediate results 5 1 Units Dataset Units Total ozone and SO column amount Dobson Units DU Total H2O column amount kg m Other trace gas column amounts molecules cm Cloud fraction and cloud top albedo optical thickness unitless Height km Pressure hPa Angles are given at Top of Atmosphere 70 km 0 to 360 degrees Geographical Coordinates longitude 0 to 360 degrees latitude 90 to 90 degrees Errors relative values 5 2 Geographical Coverage and Granularity GOME ERS 2 has a nominal global coverage at the equator after three days GOME 2 MetOp has a daily near global coverage at the equator Depending on the scanning mode used the measured ground pattern may be different The NRT operational OL and reprocessed products have by default a global coverage The
8. Longit of the sub satellite point at end of acquisition 0 360 SatellitePosition POS_VEC Position vectors X Y Z in km Vector in POS_VEC SatelliteVelocity POS_VEC Velocity vector dx dt dy dt dz dt in km s Vector in POS_VEC OrbitSemiMajorAxis float Semi major axis km float OrbitExcentricity float Excentricity float OrbitInclination float Inclination deg float OrbitRightAscOfAscNode float Right asc of asc node deg float OrbitArgumentOfPerigee float Argument of perigee deg float OrbitMeanAnomaly float Orbit mean anomaly deg float OrbitUTCDaysSince1950 integer UTC days since 1 1 1950 int OrbitMsSinceMidnight integer UTC ms since midnight int OrbitAscendingNodeCrossing CCSDS_ASCII Ascending node crossing UTC date and time CCSDS DateTime Date OrbitAscendingNodeLongitude float Ascending node longitude 180 180 UMARF notation OrbitActualDuration integer Orbit duration in minutes only counting valid pixels 0 60 SolarSpectraDate CCSDS_ASCII Date and time of the solar spectra CCSDS Date NumberOfGroundPixels integer Number of ground pixels in the product int DegradedRecordCount integer Number of records which could not be processed int DegradedRecordPercentage integer Percentage of records which could not be processed 0 100 MissingDataCount integer Number of missing data records int MissingDataPercentage integer Percentage of missing data records 0 100 27 DLR GOME PUM 01 Iss Rev 2 E Product U
9. center i e DLR e RV is the two digit product revision e TYPE denotes the product format used HDF5 or BUFR For example the following identifier denotes a GOME ERS 2 off line product GOME_03 NO2 L2 20060723165752 023 ERS2 58855 DLR_05 HDF5 The following example is a valid name for a GOME 2 MetOp off line product GOME_O3 NO2 BrO_L2_20070302111155 047 METOPA_01900_DLR_01 HDF5 Note The GOME 2 MetOp NRT products disseminated via EUMETCast have a fixed prefix file name S O3M_ see the following example S O3M_GOME_O3_L2_20070302111155 003 METOPA_01900_DLR_01 BUFR 21 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 22 of 47 5 8 Product Dissemination 5 8 1 GOME ERS 2 GOME ERS 2 products are available at the D PAF FTP server eoa dp eo esa int The products are organized in directories as follows products level 2_HDF5 YYYY IMMIDD where YYYY is the year MM the month DD the day For requesting a FTP user account see 5 9 1 5 8 2 GOME 2 MetOp The primary dissemination mean of GOME 2 MetOp NRT products is EumetCast using the BUFR and HDF5 format The NRT products in BUFR format are additionally disseminated via WMO GTS The corresponding bulletin identifier for the O3M SAF Products is Region RTH Country TTAAii CCCC CodeForm 6 OFFENBACH GERMANY TUCX01 EDLR FM 94 XIII Additiona
10. float PMDpixels degrees Latitude Point F of forward scan PMD subpixel center PMDPixelMap integer pixels Mapping from ground pixel to PMD pixel 1 for backscan SolarZenithAngleE float pixels degrees Solar zenith angle at TOA Point E SolarZenithAngleCentre float pixels degrees Solar zenith angle at TOA Point F SolarZenithAngleG float pixels degrees Solar zenith angle at TOA Point G LineOfSightZenithAngleE float pixels degrees Line of sight zenith angle at TOA Point E LineOfSightZenithAngleCentre float pixels degrees Line of sight zenith angle at TOA Point F LineOfSightZenithAngleG float pixels degrees Line of sight zenith angle at TOA Point G RelativeAzimuthE float pixels degrees Relative azimuth at TOA Point E RelativeAzimuthCentre float pixels degrees Relative azimuth at TOA Point F RelativeAzimuthG float pixels degrees Relative azimuth at TOA Point G SolarZenithAngleSatE float pixels degrees Solar zenith angle at satellite Point E SolarZenithAngleSatCentre float pixels degrees Solar zenith angle at satellite Point F SolarZenithAngleSatG float pixels degrees Solar zenith angle at satellite Point G LineOfSightZenithAngleSatE float pixels degrees Line of sight zenith angle at satellite Point E LineOfSightZenithAngleSatCentre float pixels degrees Line of sight zenith angle at satellite Point F LineOfSightZenithAngleSatG float pixels degrees Line of sight zenith angle at satel
11. is empty for GOME ERS 2 products For more information on the NO2 parameters see section 8 34 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 35 of 47 8 August 2012 6 6 3 DETAILED_RESULTS SO2 Subgroup The SO2 algorithm internally calculates results for several assumed plume heights The number of plume heights is available in the field NumberOfPlumeHeights which also describes the cardinality of the subsequent datasets denoted as heights The different height values are available in the dataset PlumeHeights Attribute Name Data Type Unit Description NumberOfPlumeHeights integer Number of assumed plume heights Dataset Name Data Type Unit Description PlumeHeights float heights km Assumed plume heights for retrieval ESCCorrected float pixels heights mol cm Slant column density background corrected AMFToGround float pixels heights AME to ground AMFToGround_Error float pixels heights Error on AMF to ground AMFToCloudTop float pixels heights AME to cloud top 1 if clear sky AMFToCloudTop_Error float pixels heights Error on AMF to cloud top 1 if clear sky AMFTotal float pixels heights Total AMF AMFTotal_Error float pixels heights Total AMF error VCDCorrected float pixels heights
12. support the GOME HDFS5 products http www stcorp nl beat ECMWF provides software for decoding BUFR products see http www ecmwf int products data software bufr html 44 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 45 of 47 8 August 2012 A Appendixes A 1 HDF5 Data Types The following table shows the correspondence between Product data types and HDF5 data types Data type HDF5 predefined data type char H5T_STD_I8LE integer H5T_STD_I32LE float H5T_IEEE_F32LE double H5T_IEEE_F64LE string H5T_C_S1 UTC H5T_COMPOUND H5T_STD_B2LE Day H5T_STD_I32LE MillisecondOfDay where Day denotes number of days since 1st of January 1950 VIEW_MODES H5T_COMPOUND H5T_STD_I32LE NominalPixels H5T_STD_B2LE StaticPixels H5T_STD_B2LE NarrowPixels H5T_STD_B2LE PolarSouthPixels H5T_STD_I32LE PolarNorthPixels CCSDS_ASCII The format for ASCII Time Code is YYYY MM DDThh mm ss ddd where YYYY Year in four character subfield with values 0001 9999 MM Month in two character subfield with values 01 12 DD Day of month in two character subfield with values 01 28 29 30 or 31 T Calendar Time separator hh Hour in two character subfield with values 00 23 mm Minute in two character subfield with values 00 59 ss Second in two character subfield with values 00 59 ddd Dec
13. 043 Atmospheric chemical or physical constituent type see table below 0 08 044 CAS registry number see table below 015021 Integrated mass density kg m 2 24 000 First order statistics follow 2 36 000 Backward reference bitmap 0 31 001 Delayed descriptor replication factor 2 0 31 031 Data present indicator 01 0 01 031 Identification of originating generating centre 254 Eumetsat 0 01 032 Generating Application Defined by local Generating Centre 1 0 08 023 First order statistics 7 Mean absolute error 0 31 001 Delayed descriptor replication factor 2 0 15 021 Scaled Integrated mass density kg m 42 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 43 0f 47 8 August 2012 7 7 Section 4 Indicator section Octet Description Allowed Values 1 3 Length of section in octets 4 Set to zero reserved 5 Binary data as defined by descriptors which begin at octet 8 Section 3 7 8 Section 5 End Section Octet Description Allowed Values 1 4 7777 coded according to the CCITT International Alphabet No 5 7777 79 Trace Gas Table The following field values are used for the different trace gases Trace gas Trace gas name Atmospheric Chemical No CAS Registry Number 08 043 descriptor 08 044 descriptor O Ozone
14. 1 3 Abbreviations and Acronyms A list of abbreviations and acronyms used throughout this document is given below AAIA AMF BIRA IASB BUFR CCSDS DLR DOAS D PAF DU EPS ERS 2 ESA ESC EUMETSAT GDOAS GDP GOME HDF IMF MetOp NRT NT NTO O3M SAF OL OTO PDU PMD RP RMS SAF SZA TBD TOA UMARF UV UPAS UTC VCD VIS Absorbing Aerosol Indicator Algorithm Air Mass Factor Belgian Institute for Space Aeronomy Binary Universal Form for the Representation of meteorological data Consultative Committee for Space Data Systems Deutsches Zentrum fiir Luft und Raumfahrt e V German Aerospace Centre Differential Optical Absorption Spectroscopy German processing and archiving facility Dobson Unit EUMETSAT Polar System European Remote Sensing Satellite 2 European Space Agency Effective Slant Column European Organisation for the Exploitation of Meteorological Satellites GODFIT DOAS GOME Data Processor Global Ozone Monitoring Experiment Hierarchical Data Format Remote Sensing Technology Institute Operational Meteorological Satellite Near Real Time Nominal Time Identifier used for near real time total column and cloud products SAF on Ozone and Atmospheric Chemistry Monitoring Off Line Identifier used for off line total column and cloud products Product Dissemination Unit Polarisation Measurement Device Postfix identifier user for reprocessed total column and cloud products Root Mean Square Satel
15. 4 Issue 3 12 April 2006 A4 Product Requirements Document SAF O3M FMI RQ PRD 001 Rev 06 May 2008 1 2 1 Reference Documents R1 P Valks D Loyola N Hao M Rix S Slijkhuis Algorithm Theoretical Basis Document for GOME 2 Total Column Products of Ozone NO2 BrO SO2 H20 HCHO OCIO tropospheric NO2 and Cloud Properties GDP 4 5 for O3M SAF OTO and NTO DLR GOME 2 ATBD 01 Iss Rev 2 E 2011 R2 R Spurr M van Roozendael D Loyola C Lerot J van Geffen J van Gent C Fayt J C Lambert W Zimmer A Doicu S Otto D Balis M Koukouli C Zehner GDP 5 0 Upgrade of the GOME Data Processor for Improved Total Ozone Columns Algorithm Theoretical Basis Document DLR GOME ATBD GDP5 Iss Rev 1B August 2012 R3 Algorithm Theoretical Basis Document for GOME Total Column Densities of Ozone and Nitrogen Dioxide UPAS GDOAS GDP 4 0 ERSE DTEX EOPG TN 04 0007 Iss Rev 1 A December 2004 R4 J C Lambert M Koukouli D Balis J Granville C Lerot and M Van Roozendael GDP 5 0 Upgrade of the GOME Data Processor for Improved Total Ozone Columns Validation Report TN IASB GOME GDPS5 VR Iss Rev 1B August 2012 R5 D Balis M Koukouli D Loyola P Valks N Hao GOME 2 O total column validation report SAF O3M AUTH VR 03 3 November 2009 R6 J C Lambert G Pinardi J Granville K Clemer A Delcloo P Valks N Hao 9 DLR GOME PUM 01 Product User Manual for GOME Total C
16. DLR Product User Manual for GOME Total Columns of Ozone NO tropospheric NO BrO SO H 0 HCHO OCIO and Cloud Properties O3M SAF OTO and NTO Dobson Units 200 300 400 Doc No DLR GOME PUM 01 Iss Rev 2 E Date 8 August 2012 Deutsches Zentrum f r Luft und Raumfahrt e V DLR Oberpfaffenhofen Germany DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 2 of 47 Signatures Action Name Affiliation prepared by D Loyola R DLR MF W Zimmer DLR MF Function Date Signature GOME Project Manager GOME Project Engineer S Kiemle DLR DFD DIMS Project Manager usust 2012 P Valks DLR MF GOME Project Scientist M Pedergnana DLR MF GOME Project Engineer H20 HCHO by former S Emmadi DLR MF GOME Project Engineer gt March 2011 BUFR v3 by former L Butenko DLR MF GOME Project Engineer 14 June 2006 HDES by Former 1 November Y Livschitz DLR MF GOME Project Engineer 2004 released by D LoyolaR DLR MF GOME Project Manager August 2012 Distribution List Function Organization UPAS Team DLR MF DLR DFD GOME ERS 2 Team ESA BIRA RTS AUTH various O3M SAF Team EUMETSAT FMI AUTH BIRA KNMI various Product User Manual for GOME Total Columns of Ozone NO2 tropospheric N
17. DLR together with the partner organizations ESA and EUMETSAT will assure the continuity between GOME ERS 2 and GOME 2 MetOp total column products In this framework it is important to provide to the users a unified data format for accessing the GOME products The Hierarchical Data Format HDF and the Binary Universal Form for the Representation of meteorological data BUFR have been selected for the GOME total column products HDF and BUFR are self describing machine independent file formats commonly used for storage and transfer of scientific and meteorological data The present document is divided into the following sections e Overview of the GOME ERS 2 and GOME 2 MetOp instruments including instrument modes e Summary of the algorithms used for the retrieval of trace gases total columns and cloud properties e Summary of the processing steps e Product description including the used HDF5 and BUFR format e Appendixes Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 9 of 47 8 August 2012 1 2 References 1 2 1 Applicable Documents A1 Design Document for the GOME 2 Universal Processor for Atmospheric Spectrometers SAF O3M DLR DD 001 Issue 2 0 October 2003 A2 EECF to PAF Interface Specifications ER IS EPO GE 0102 Issue 3 0 January 1990 A3 UMARF to SAFs Interface Control Document EUM UMA ICD 00
18. Figure 5 Ground Pixel Geometry The term pixels denote the number of ground pixels whereas the term PMDpixels denote the total number of PMD subpixels JQ DLR GOME PUM 01 Iss Rev 2 E 8 August 2012 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO and Cloud Properties DLR Page 30 of 47 The data sets in the GEOLOCATION group are given in the following table Dataset Name Data Type Unit Description InternalPixelld integer pixels Internal ground pixel number Time UTCl pixels ms Time of the observation in UTC format LongitudeCentre float pixels degrees Longitude of the centre of the ground pixel Point F LatitudeCentre float pixels degrees Latitude of the centre of the ground pixel Point F LongitudeA float pixels degrees Longitude Point A LatitudeA float pixels degrees Latitude Point A LongitudeB float pixels degrees Longitude Point B LatitudeB float pixels degrees Latitude Point B LongitudeC float pixels degrees Longitude Point C LatitudeC float pixels degrees Latitude Point C LongitudeD float pixels degrees Longitude Point D LatitudeD float pixels degrees Latitude Point D PMDCenterLon float PMDpixels degrees Longitude Point F of forward scan PMD subpixel center PMDCenterLat
19. GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 38 of 47 6 8 3 NO2Tropo_Flags Flag Value Description 0 1 Polluted condition VCDTropo and VCDCorrected values are available e VCD contains the total column density based on an unpolluted AMF e VCDCorrected contains the pollution corrected total column density e VCDTropo contains the tropospheric column density Note IntensityWeightedCloudFraction lt 50 1 2 Unpolluted condition VCDTropo and VCDCorrected not available fill values e VCD contains the total column density based on an unpolluted AMF Note IntensityWeightedCloudFraction lt 50 2 4 Cloudy condition VCDTropo and VCDCorrected not available fill values e VCD contains the total column density based on an unpolluted AMF Note IntensityWeightedCloudFraction gt 50 3 8 Measurement in polar regions Lat gt 70 deg VCDTropo and VCDCorrected not available fill values e VCD contains the total column density based on an unpolluted AMF 4 16 NO2 column data not available e VCD VCDTropo and VCDCorrected contain fill values For more information on the NO2 parameters see Section 8 6 8 4 SO2_Flags Flag Value Description 0 1 Measurement in polar regions SZA gt 75 deg e reduced quality of SO2 total column 1 2 SO2 column
20. InstrumentID string Instrument which acquired the product GOME GOME InstrumentMode VIEW_MODES Specifies how many ground pixels were VIEW_MODES VIEW_MODES structure observed in the corresp view modes structure structure SensingStartTime CCSDS_ASCI UTC date and time at sensing start Date in CCSDS Date in CCSDS format ASCII format ASCII SensingEndTime CCSDS_ASCH UTC date and time at sensing end Date in CCSDS Date in CCSDS format ASCII format ASCII ReceivingCentre string Centre that received the data KS GS DP ES ECF for EECF MS FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV ProcessingCentre string Centre that generated the data D PAF DLR OP O3DLR ProcessingMode string Processing mode applied for generation N nominal N nominal of the product B backlogged B backlogged R reprocessed R reprocessed V validation V validation T near real time T near real time Revision string Global product revision required e g for string string reprocessing part of logical product identifier ProductType string Description of the product type ERSNTO O3MNTO ERSOTO O3MOTO Js Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 27 of 47 8 August 2012 Allowed Attr
21. O2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 3 of 47 8 August 2012 Document Change Log Issue Rev Date Section Description of Change 1 A 31 July 2004 all HDF5 and BUFR output product format to documents merged in this product user 20 July 2006 manual 1 B 5 October 2006 4 5 Content of chapters added 1 C 10 November 2006 all First official version of this document 1 D 6 March 2007 15 7 Fix file name convention 6 2 6 5 Added VCDQualityIndicator QualityFlags CloudMode CloudType AMFTotal AMFTotal_Error OrbitActualDuration new receiving stations 1 E 30 April 2008 jall Revised following ORR A 6 Added in HDF5 section IterativeVCDNumberOflterations a priori O3_Profile T_ Profile 7 BUFR product update to BUFR version 4 2 A 9 December 2008 all Revised following ORR B 28 January 2009 6 Finalized HDF5 product format Moved trace gas specific datasets into own groups inside DETAILED_RESULTS Moved cloud properties into own group 2 B 16 November 2009 6 Update H2O and HCHO format new sections 6 6 4 6 6 5 6 7 4 6 7 5 Minor corrections SurfaceAlbedoRW SurfaceAlbedo Total Columns and BrO cleanup 18 December 2009 6 PixelFlag under Geolocation section is renamed to SurfaceConditionFlag SurfaceConditionFlag definition added H2OFlag definition changed DLR GOME PUM 01 Product User Manual for GOME Total Columns of
22. Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 4 of 47 2 C 23 April2010 1 1 Add reference to reprocessed GOME 2 5 9 2 Add new O3M SAF logo and web page 6 4 Finalized NO2 HDES entries 6 2 Added PMD dataset descriptions 7 2 Add WMO GTS bulletin identifier 8 New section 6 8 4 New flag value added to SO2_Flag 6 8 6 New flag value added to HCHO_Flag 2 D 25 March 2011 6 8 1 Renamed SurfaceCondition_Flag to SurfaceConditionFlags 6 2 Removed obsolete FittingFlag AMFFlag and VCDFlag 6 8 5 New definitions for H2O_Flags 6 3 Converted ViewMode to integer and added DescendingFlag 2 E 8 August 2012 4 1 Added new chapter GDP 5 0 used for 6 7 GOME ERS 2 O products Added CHOCHO entries for future use globally 6 6 2 Added NO entries AMF Tropo Error field AMF Tropo To Ground Error field AMF Tropo To Cloud Error field VCD Corrected Error field VCD Strato Error field Averaging Kernel field Averaging Kernel Pressure field Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 5 of 47 8 August 2012 Table of Contents I Introducton ae seas sod daabdenasaniavddseteiaoeedeteseabianiuns 7 1 1 Purpose and Scope ns een sawn ny Rite sited a a E 7 TX Referene nennen 9 1 2 1 Applicable Doc
23. RESULTS_GODFIT Group 36 6 8 Detailed Flag Description ana aD 37 6 8 1 SurfaceConditionFlags sseeeeeeseeseeeseessesseeseessreseeseessreseessrssseesssreessreesereessee 37 6 8 2 CUA EVE LAGS nase eines 37 6 8 3 NO2Tropo Flags ee 38 LS ore VARS ot Fz er E E R ee 38 08 3 3 H20 Rlass ae sy oh oor besten irae va dons areas ane wee eas aE Raa E eaae aiias 38 6 8 6 HCHO Flaps aaee araia eaaa EA aaa E leu vadgneseiveandaraseavaneas 39 7 BUFR Product Format Description orssssssssssossesosssonsssnnsnssssnnnssnnssnnnssonsnnnsunsnnnnen 40 7 1 SUUCUUEC EE E T 40 7 2 WMO GTS Bulletin Identifier seen ee ea 40 7 3 Section 0 Indicator Section an au an 41 7 4 Section 1 Identification Section ur cnssssnreonneosnssoneesnnnsnnnennnnsnnnsnnnsnnnessnnnnessnnnn 41 7 5 Section 3 Indicator Section kennen 41 7 6 Section 3 UPAS Level 2 Specific List of Descriptors ee eeseeseeseeceeeeeeeeeees 42 7 7 Section 4 Indicator secti n chen 43 7 8 Section o End Sectoti ara 43 7 9 Trace Gas Table a seine 43 8 Using the Products ana aan duvdiuas sesssivestvusdivevieusnedenstens 44 8 1 Confidence Flags and Ancillary Fields ccccesscssseseseceseeeseeeeseeeceeeeeceeeeeeeeees 44 8 2 Software and Tools for reading the products ccsceseseeeseeeseceseeeseeeeeeeeeeeseeeees 44 AL Appendixes nee 45 A HDES Data Typs nen a a ee 45 A 2 Traceability Matrix of HDF5 Metadata to EECF Parameters
24. SECTION The values in all sections are either copied from the level 1 R11 R12 or other input data or calculated by the level 1 to 2 processor Each of the sections of a BUFR message is made up of a series of octets The term octet meaning 8 bits was coined to avoid having to continually qualify byte as an 8 bit byte The DATA DESCRIPTION section contains a list of descriptors defining the structure and the format of data following in DATA SECTION This is called self descriptive nature of BUFR The strength of this self descriptive feature is in accommodating change For example if new observations or observational platforms are developed there is no need to invent a new code form to represent and transmit the new data all that is necessary is the publication of additional data description tables Similarly for the deletion of possibly outdated observations instead of having to send missing indicators for a long period while awaiting a change to a fixed format code the missing data are simply not sent in the message and the data description section is adjusted accordingly The data description tables are not changed however so that archives of old data may be retrieved The data encoded in BUFR format is purely binary or bit oriented thus making it both machine dependent and at the same time machine independent The dependency comes in the construction or interpretation of BUFR messages there is not much for a human to
25. SatellitePointStartLat 90 0000 to 89 9999 LLOE SubSatellitePointEndLon 180 0000 to 179 9999 LLOS SubSatellitePointStartLon 180 0000 to 179 9999 LONS StartOrbitNumber LSVL OrbitAscendingNodeLongitude 180 0000 to 179 9999 LSVT OrbitAscendingNodeCrossingDateTime CCSDS date PPRC ProcessingCentre possible values D PAF DLR OP ERS O3DLR METOP PPST Processing End Date and Time CCSDS date QDLC MissingDataCount QDLP MissingDataPercentage QDRC DegradedRecordCount QDRP DegradedRecordPercentage QQAI Applicable Associated Quality Information QQOV Applicable Overall quality flag OK NOK RRCC ReceivingCentre ECF FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV SMOD InstrumentMode e g NARROW NORMAL or STATIC SNIT Applicable CCSDS date SSBT SensingStartTime CCSDS date SSST SensingEndTime CCSDS date Parameter is not contained in the HDF5 product but will be provided by DIMS AT
26. TAL_COLUMNS group contains the same value as the VCD entry for the NO2 window in DETAILED_RESULTS These two entries contain the total NO column density based on an unpolluted AMF The VCDcorrected entry in DETAILED_RESULTS NO2 contains the pollution corrected total NO column density available only for measurements with an intensity weighted cloud fraction lt 50 and for latitudes lt 70 deg Note that VCDcorrected gt VCD The NO2Tropo entry in the TOTAL_COLUMNS group contains the same value as the VCDTropo entry in DETAILED_RESULTS NO2 These two entries contain the tropospheric NO column density available only for measurements with an intensity weighted cloud fraction lt 50 and for latitudes lt 70 deg The VCDStrato entry in DETAILED_RESULTS NO2 contains the stratospheric NO column density as derived with a spatial filtering approach and available only for latitudes lt 70 deg 8 1 Confidence Flags and Ancillary Fields The users should check the quality flags associated with each trace gas and cloud product Detailed information is given in the corresponding tables 8 2 Software and Tools for reading the products The HDF5 products can be read using the standard HDF software and tools available at http www hdfgroup org products hdf5_tools the above Web page contains HDF5 libraries for a number of programming languages The BEAT and VISAN tools for ingesting processing and analyzing atmospheric remote sensing data fully
27. al in each channel Figure 1 GOME optical layout courtesy of ESA ESTEC 12 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 13 of 47 8 August 2012 2 2 GOME ERS 2 In June 1990 the ESA Council approved the satellite project to follow the first European Remote Sensing Satellite ERS 1 The ERS 2 satellite was intended to provide data continuity between ERS 1 and the European polar platforms ERS 2 was launched on 21 April 1995 In addition to the ERS 1 mission objectives ERS 2 was scheduled to make a significant contribution to atmospheric chemistry To meet this need ERS 2 carried GOME an instrument designed to measure a range of atmospheric trace constituents in the troposphere and stratosphere GOME ERS 2 is a nadir viewing spectrometer which in its normal mode scans across track in three steps The field of view of each step may be varied in size from 40 km x 40 km to 320 km x 40 km with five options allowed The mode with the largest footprint three steps with a total coverage of 960 km x 40 km provides global coverage at the equator within 3 days DLR developed the GOME Data Processor GDP system the operational ground segment for GOME ERS 2 GDP incorporates a Level 0 to 1 processing chain the complete GOME ERS 2 data archive a DOAS based total column retrieval process Level 1 to 2 and processing
28. chain for the generation of value added products 2 3 GOME 2 MetOp On 30 January 1998 the ESA Earth Observation Programme Board gave its final go ahead for the MetOp Programme The instruments on the MetOp satellites are designed to produce high resolution images of the Earth s surface vertical temperature and humidity profiles and temperatures of the land and ocean surface on a global basis In addition there are instruments for monitoring trace gases and wind flow over the oceans This instrument payload is of significant value to meteorologists and other scientists particularly to those studying the global climate Given the need for global scale routine monitoring of the abundance and distribution of ozone and associated trace gas species a proposal was put forward for the inclusion of GOME 2 on the MetOp satellites MetOp A was launched on 19 October 2006 as part of the Initial Joint Polar System IJPS in co operation with NOAA in the USA The GOME 2 MetOp field of view of each step may be varied in size from 5 km x 40 km to 80 km x 40 km The mode with the largest footprint twenty four steps with a total coverage of 1920 km x 40 km provides daily near global coverage at the equator 10 Based on the successfully work with the GOME Data Processors the German Aerospace Centre DLR plays a major role in the design implementation and operation of the GOME 2 MetOp ground segment for total column products DLR is a partner in the Satelli
29. coverage of trace gases available only under special conditions may be reduced e g SO measured during volcanic eruption The NRT products have the same granularity as the downlink or PDU The OL and reprocessed products are consolidated orbits from ascending node to ascending node 5 3 Spatial Resolution GOME ERS 2 has three forward scan pixels with a nominal resolution of 40 km x 320 km and one back scan pixel with a nominal resolution of 40 km x 960 km GOME 2 MetOp has 24 forward scan pixels with a nominal resolution of 40 km x 80 km and 8 back scan pixels with a nominal resolution of 40 km x 240 km Both forward and back scan pixels are generally processed and written to the products 19 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 20 of 47 5 4 Delivery Time DLR generates near real time NRT off line OL and reprocessed products RP The NRT products are available for distribution in less than 15 minutes after the reception of the GOME level 0 or level 1 product Assuming that the input data is received at DLR 1 45 hours after sensing then the GOME total column products will be disseminated to the users in less than 2 hours after sensing The GOME 2 MetOp OL products are available two weeks after sensing The GOME ERS 2 OL products are available up to four weeks after sensing due to con
30. cts can be done via dedicated user services The GOME 2 MetOp level 1 products are delivered in NRT approx 1 45 hours after sensing in so called PDU files product dissemination unit containing 3 minutes of measurements via EUMETCast The ground segment at DLR needs less than 15 minutes for acquiring the input data retrieving the trace gas total columns and disseminating the resulting level 2 products Figure 2 that means the GOME 2 MetOp total column products are available to the users in less than 2 hours after sensing aff Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 17 of 47 8 August 2012 The GOME 2 MetOp operational processing is performed in a high availability virtualized environment on a blade center farm Broadcast Online and and ine Delivpry Internet T 7 Downloa d EumetCa st Receiving tT GOME L3 f St a ns Fr j 2 i 7 ssimilatio u GOMEL2 HB Figure 2 GOME 2 MetOp processing chain 4 3 Data Management The processing of GOME 2 MetOp data is embedded in DLR s multi mission facility ensuring high availability and sustainability The German National Remote Sensing Data Library stores the data for the long term enabling monitoring of global change and data reprocessing based on enhanced methodology Information and data of O3M SAF products generated at DLR are dissemi
31. data not available e VCD and VCDCorrected contain fill values 2 4 SO2 column data not available due to database e VCD and VCDCorrected contain fill values 6 8 5 H2O_Flags Flag Value Description 0 1 Measurement in cloudy conditions e reduced quality of H2O total column 1 2 Measurement in cloudy and or elevation conditions small O2 e reduced quality of H2O total column 38 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 39 of 47 8 August 2012 6 8 6 HCHO_Flags Flag Value Description 0 1 Measurement with high solar zenith angle SZA gt 70 deg e reduced quality of HCHO total column 1 2 Cloudy conditions e reduced quality of HCHO total column Note CloudFraction gt 40 2 4 HCHO column data not available e HCHO contains fill values 3 8 HCHO column data not available due to database issues e HCHO contain fill values 39 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 40 of 47 7 BUFR Product Format Description 7 1 Structure The data in the BUFR file is organized in six sections INDICATOR SECTION IDENTIFICATION OPTIONAL SECTION DATA DESCRIPTION DATA SECTION and END
32. dure fill in values are written to the arrays Also not all datasets defined here have to exists in every product Please note that this description is only valid for the actual version of the product format currently 2 E The version of a GOME HDFS5 level 2 product can reliably be read from the field META_DATA ProductFormatVersion therefore a reader can implement several versions in parallel Each array has five attributes Title Unit FillValue ValueRangeMin and ValueRangeMax Figure 4 These are used to describe the contents of the array Values in the META_DATA group are stored as attributes of the group META_DATAI GEOLOCATIONI Attributes present for i every dataset Time 0 12 IN Title Longitude 0 1 2 Unit Latitude ol l2l n FillValue ValueRangeMin TOT L_COLUMNSI ValueRangeMax 03 01 2 N ne ER EN E N nuber of ground pixels BrO 0 11 2 N M nuber of fitting windows CLOUD_PROPERTIES CloudFraction 0 1 2 iN DETAILED_RESULTS ESC 0 1 2 N 1 O3 03Temperature 0 1 2 N Figure 4 Organization of the GOME total column products in the HDF5 structure a5 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 Augus
33. e is organized in five groups META_DATA GEOLOCATION TOTAL_COLUMNS DETAILED_RESULTS CLOUD_PROPERTIES Figure 4 The values in all groups are either copied from the level 1 R11 R12 or other input data or calculated by the UPAS level 1 to 2 processor The META_DATA group contains parameters required by EECF A2 or UMARF A3 and general information about the product The data related to each ground pixel is divided into three groups GEOLOCATION TOTAL_COLUMNS and DETAILED_RESULTS The GEOLOCATION group contains all information related to geolocation of the pixel Pixel processing information is stored in the TOTAL_COLUMNS and DETAILED_RESULTS groups Cloud properties derived are stored in the CLOUD_PROPERTIES group The last three groups mentioned above contain all pixel information stored in arrays with length equal to the number of ground pixels in one granule orbit or PDU Data values may occur more than once for a given ground pixel and these will be separated by fitting windows The information for each entry is stored as a matrix Elements in these matrices aise Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 25 of 47 8 August 2012 are not always atomic they can contain variable length data structures When entries for a pixel or pixel window combination cannot be calculated using the normal processing proce
34. ee below AveragingKernels float pixels layers Averaging kernels for each atmosphere layer For the fitting parameters the general name scheme is FitParN_ lt name gt where N is the number of the fitting parameter and lt name gt the corresponding name With this approach the desired dataset can be retrieved from the product even if the position in the fitting vector should change in the future The Covariance dataset contains a square matrix with the dimensions of the fitting vector In the lower left triangle the covariance is available the diagonal contains the variance and the upper right triangle contains the correlation cory Cov sqrt covii cov for j gt i upper right triangle 36 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 37 of 47 8 August 2012 6 8 Detailed Flag Description 6 8 1 SurfaceConditionFlags Flag Value Description 0 1 Land Sea Set when at least 60 of the ground pixel s area is classified as sea 1 2 Sun glint Set when at least one of the PMD subpixels is affected by sunglint 2 4 Snow Ice These flags give additional information about the surface state during the retrieval 6 8 2 QualityFlags Fla Val Ah Specified Valid Conditions ie Description g 03 NO2 BrO S02 H20 HCHO OCIO 0 1 Invalid total column re
35. ervices are accessible through the websites given in section 5 9 and at the end of this section The interactive catalogue and ordering interface EOWEB from DLR allows individual product searches and ordering Catalogue information from the O3M SAF products generated at DLR are regularly made available to the central EUMETSAT facility UMARF The users can query the catalogue of the UMARF and submit their request the UMARF facility will then send to each SAFs orders requested by the end users about SAF products catalogued in UMARF DLR s data management system will then deliver the requested products to the user DLR operates additionally on line user services on remote sensing data in the framework of the World Data Center for Remote Sensing of the Atmosphere WDC RSAT http wdc dlr de left side of Figure 2 GOME 2 MetOp images and value added products produced at DLR and partner organizations are available at http atmos eoc dlr de gome2 see Figure 3 GOME 2 MetOp A at DLR Mozilla Firefox lt 2 gt File Edit View History Bookmarks Tools Help oo amp B http atmos caf dir de gome2 9 4 Startseite von Mozilla web Postkorb Mein LEO Ergebnisse f r 2 Microsoft Outlook we gt GOME 2 MetOp A at Department Atmospheric Processors Applied Remote Sensing Cluster GOME ERS 2 GOME 2 MetOp A Product Navigation DLR genera oi Chemistry ng 9 0 2735 zotero 9 gt 05 Now Snow
36. esesseeeeseeeees 46 A 3 Traceability Matrix of HDF5 Metadata to UMARF Parametes eseeseeeees 47 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 7 of 47 8 August 2012 1 Introduction 1 1 Purpose and Scope DLR has been producing on an operational basis a range of total column trace gases and cloud products for GOME ERS 2 in the framework of ESA s D PAF project In the same way DLR produces total column trace gases and cloud products for GOME 2 MetOp in the framework of EUMETSAT s O3M SAF DLR has a long experience in operational processing of GOME data and has developed a generic software for this purpose the Universal Processor for UV VIS Atmospheric Spectrometers UPAS 9 system This document is the user manual for the GOME ERS 2 and GOME 2 MetOp total column trace gases and cloud products available at DLR In this document the terms GOME ERS 2 and GOME 2 MetOp are used to reference the specific instruments The general term GOME applies to both sensors The trace gases total column products are e Ozone O total column e Nitrogen dioxide NO total column e Bromide monoxide BrO total column e Sulphur dioxide SO total column e Water vapour H O total column e Formaldehyde HCHO total column e Chlorine dioxide OCIO total column e Glyoxal CHOCHO total column The trace gases tropo
37. et to zero reserved 8 A collection of descriptors which define the form and content of individual data elements comprising one data subset in the data section 41 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 42 of 47 7 6 Section 3 UPAS Level 2 Specific List of Descriptors Descriptor Description Value 0 01 007 Satellite Identifier 5 Metop 2 0 02 019 Satellite Instruments 220 GOME 2 301011 Date in format YYYY MM DD 0 04 001 0 04 002 0 04 003 301013 Time in format HH MM SS 0 04 004 0 04 005 0 04 006 301021 Latitude Longitude Centre 0 05 001 0 06 001 102 004 Repeat next 2 fields 4 times for four corners of a pixel 0 27 001 Latitude High Accuracy 0 28 001 Longitude High Accuracy 0 10 001 Height of land surface 0 14 019 Surface Albedo 0 0 1 0 0 07 025 Solar zenith angle 0 10 080 Viewing Zenith Angle 0 05 023 Sun to satellite azimuth difference 0 20 010 Cloud Cover Total 0 08 003 Vertical significance 2 Cloud top 0 07 004 Pressure pa 0 14 026 Albedo at the top of clouds 0 0 1 0 0 20 014 Height of top of clouds km 0 13 093 Cloud optical thickness 0 31 001 Delayed descriptor replication factor 2 0 07 004 Pressure Top 0 07 004 Pressure Bottom 0 08
38. ground pixels denoted as pixels in the following tables and M the number of fitting windows denoted as windows in the following tables Dataset Name Data Type Unit Description AAI float pixels Absorbing aerosol indicator SurfaceHeight float pixels km Surface altitude SurfacePressure float pixels hPa Pressure at the surface level SurfaceConditionFlags integer pixels Flag for different pixel retrieval conditions e g land sea sun glint or snow ice see 6 8 1 SurfaceAlbedo float pixels windows Surface albedo for the associated retrieval window Quality_Flag integer pixels windows Quality flags for each pixel window see 6 8 2 VCD float pixels windows mol cm Vertical column density of main parameter value VCD_Error float pixels windows Error on vertical column density IntensityWeightedCloudFraction float pixels windows Weighting factor between clear sky and cloudy AMFs ESC float pixels windows mol cm Retrieved effective slant column ESC_Error float pixels windows Error on effective slant column FittingRMS float pixels windows RMS of the fit FittingChiSquare float pixels windows Square of Chi FittingGoodness float pixels windows Goodness of fit for the fitting window FittingNumberOflterations integer pixels windows Number of iterations of non linear fitting GhostColumn float p
39. he effective optical throughput is enhanced by approximately a factor of 2 and co adding as used for GOME ERS 2 is not required because of the higher data rate 10 times faster J Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 15 of 47 8 August 2012 3 Algorithm Description 3 1 Summary The GOME Data Processor GDP operational algorithm is the baseline algorithm for the trace gas column retrievals from GOME ERS 2 and GOME 2 MetOp The GDP 4 x uses an optimised DOAS Differential Optical Absorption Spectroscopy algorithm to determine the trace gas slant column The DOAS slant column fitting is followed by Air Mass Factor AMF conversions to generate vertical columns Cloud information used in the trace gas retrieval is obtained with the OCRA and ROCINN algorithms The latest development GDP 5 uses the GODFIT algorithm for the retrieval of total ozone from GOME ERS 2 A detailed description of the GDP algorithms are given in R1 R2 and R3 3 2 Trace Gas and Cloud Products The GOME ERS 2 and GOME 2 MetOp trace gas column densities and cloud properties level 2 product are retrieved from GOME ir radiance and PMD data level 1 product The following table lists the trace gas column and cloud products provided by DLR and the corresponding wavelength regions used for the retrieval
40. ibute Name Data Type Description JP P Values ProcessingLevel string Processing level applied for generation of the product 02 ProcessingTime CCSDS_ASCI UTC date and time at processing finish CCSDS Date BaseProductAlgorithmVersion string Version of the algorithm used to generate the L1B string parent product upon which the L2 product is based BaseProducts string Name of the base products string ProductAlgorithmVersion string Version of the algorithm that produced the product string InitializationFile Version string Version of the configuration file used for processing string InternalProcessorRevision string Version of the processor used to generate this product string ProductFormatType string Data format of the product HDF5 ProductFormatVersion string Version number of the product format string ProductContents string Trace gases included in the product comma separated string list SubsettingRegion string Description of the sub setting region full means no string subsisting was applied SubSatellitePointStartLat float Latitude of the sub satellite point at start of 90 90 acquisition For EPS products either the first measurement or first complete scan start point tbd at start of dataset SubSatellitePointStartLon float Longit of the sub satellite point at start of acquisition 0 360 SubSatellitePointEndLat float Latitude of the sub satellite point at end of acquisition 90 90 SubSatellitePointEndLon float
41. imal fraction of second where each d has values 0 9 POS_VEC H5T_COMPOUND HST_IEEE F64LE X HST_IEEE F64LE Y H5T_IEEE_F64LE Z 45 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 46 of 47 A 2 Traceability Matrix of HDF5 Metadata to EECF Parameters The EECF metadata parameters A2 which are applicable to the D PAF products are stored in the HDF5 file as attributes in the META_DATA group The tracing of EECF parameters to the attributes in the product file is indicated in the following table Attributes can only take values which are allowed by EECF EECF Short Name Attribute Name Notes SATELLITE_ID SatelliteID possible values ERS M01 M02 for METOP SENSOR_ID InstrumentID GOME ORBIT_NO StartOrbitNumber ACQUISITION_FACILITY_ID ReceivingCentre ECF FBK FUC GCA PGS RUS SOC SVL UBI WAL WEC WIV PROCESSING_FACILITY_ID ProcessingCentre D PAF DLR OP ERS O3DLR ArchiveFacility METOP PROCESSING_DATE_TIME ProcessingTime TEMPORAL_COVERAGE_START SensingStartTime TEMPORAL_COVERAGE_STOP SensingEndTime SOFTWARE_VERSION ProductAlgorithmVersion AUX_DATA InitializationFileVersion PRODUCT_TYPE ProcessingLevel 02 or 03 REVISION Revision SOURCE_ITEM BaseProducts AG Product User Manual for GOME Tota
42. iveVCDNumberOf integer pixels Iterations Number of iterations for the iterative VCD algorithm 6 6 2 DETAILED_RESULTS NO2 Subgroup Dataset Name Data Type Unit Description AMFTropoToGround float pixels l Tropospheric AMF for cloud free part AMFTropoToGround_Error float pixels Error on Tropospheric AMF for cloud free part AMFTropoToCloudTop float pixels l AMF for cloudy part 1 if clear sky AMFTropoToCloudTop_Error float pixels Error on AMF for cloudy part 1 if clear sky AMFTropo float pixels l Tropospheric AMF AMFTropo_Error float pixels Error on tropospheric AMF VCDStrato float pixels mol cm Stratospheric vertical column density VCDStrato_Error float pixels Error on stratospheric vertical column density VCDTropo float pixels mol cm Tropospheric vertical column density VCDTropo_Error float pixels Error on tropospheric vertical column density VCDCorrected float pixels mol cm Total vertical column density corrected for tropospheric contribution VCDCorrected_Error float pixels Error on corrected total vertical column density NO2Tropo_Flag integer pixels Flag indexing tropospheric NO2 calculations see 6 8 3 on page 38 AveragingKernel float pixels Total Cloudy Average Kernel layers 24 layers AveragingKernelPressure oo Total Cloudy Average Kernel Pressure layers 24 ayers Please note that this section
43. ixels windows mol cm Ghost column used in VCD AMFToGround float pixels windows AMF to ground for species AMFToGround_Error float pixels windows Error on AMF to ground AMFToCloudTop float pixels windows AMF to cloud top for species 1 if clear sky AMFToCloudTop_Error float pixels windows Error on AMF to cloud top 1 if clear sky AMFTotal float pixels windows Total AMF AMFTotal_Error float pixels windows Total AMF error The following subsections contain sub groups of the DETAILED_RESULTS group which contain trace gas specific data Bar DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 34 of 47 6 6 1 DETAILED_RESULTS O3 Subgroup In the following table the number of atmospheric layers is denoted as layers in profile datasets Dataset Name Data Type Unit Description ESCRingCorrected float pixels mol cm Retrieved effective slant column ring corrected for ozone O3Temperature float pixels K Fitted ozone temperature RingCorrection float pixels Applied ring correction factor O3Profile float pixels layers DU A priori O profile used in the retrieval of O layers 13 optional parameter TemperatureProfile float pixels layers K A priori temperature profile used in the retrieval of O layers 13 optional parameter Iterat
44. l Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 47 of 47 8 August 2012 A 3 Traceability Matrix of HDF5 Metadata to UMARF Parameters The UMARF metadata parameters A3 applicable to the O3M SAF products are stored in the HDF5 file as attributes in the META_DATA group The mapping of UMARF parameters to product file attributes is shown below again attributes can only take values allowed by UMARF a P Attribute Name Notes AARF ArchiveFacility possible values D PAF DLR OP ERS O3DLR METOP ABID ProductContents Spectral Band Ids AIID InstrumentID GOME APAS Applicable Product Size APNA Applicable Product Name APNM ProductType e g O3MOTO O3MNTO APPN BaseProducts Parent Product Name ASTI SatelliteID possible values ERS M01 M02 M03 for METOP AVBA BaseProductAlgorithmVersion AVPA ProductAlgorithmVersion Concatenation of the HDF5 attributes ProductAlgorithmVersion InitializationFileVersion InternalProcessorRevision and Revision GDMD Applicable Disposition Mode T O or P GGTP Applicable GranuleType DP GNFV ProductFormatVersion GORT Applicable OrbitType LEO GPLV ProcessingLevel 02 or 03 GPMD ProcessingMode N B R V LLAE SubSatellitePointEndLat 90 0000 to 89 9999 LLAS Sub
45. lite Point G RelativeAzimuthSatE float pixels degrees Relative azimuth at satellite Point E RelativeAzimuthSatCentre float pixels degrees Relative azimuth at satellite Point F RelativeAzimuthSatG float pixels degrees Relative azimuth at satellite Point G SubSatellitePointLongitude float pixels degrees Geodetic longitude of subsatellite point SubSatellitePointLatitude float pixels degrees Geodetic latitude of subsatellite point SatelliteAltitude float pixels km Geodetic altitude of satellite EarthRadius float pixels km Radius of the Earth 30 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 31 0f 47 8 August 2012 Dataset Name Data Type Unit Description IndexInScan integer pixels Index of the pixel within the scan 0 2 forward scan 3 backward scan SubPixellnScan integer pixels Subpixel within the scan 0 3 for GOME ERS 2 0 to 3 7 or 31 for GOME 2 MetOp ViewMode integer pixels Scanning mode of the instrument at the time of acquisition bits 0 7 geolocation flags bit 8 31 Allowed values Nominal 0 Narrow 1 Static 2 SouthPolar 3 NorthPolar 4 DescendingFlag bit 8 set if the pixel is located in the descending part of the orbit 6 4 TOTAL_COLUMNS Group The data sets in the TOTAL_COLUMNS group are given in the following table
46. lite Application Facility Solar Zenith Angle To be Defined Top of Atmosphere Unified Meteorological Archiving and Retrieval Facility Ultra Violet Universal Processor for UV VIS Atmospheric Spectrometers Universal Time Coordinate Vertical Column Density Visible 11 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 12 of 47 2 GOME Instruments 2 1 Introduction The Global Ozone Monitoring Experiment GOME is a scanning spectrometer that captures light reflected from the Earth s surface and atmosphere The spectrometer splits the light into its spectral components covering the UV VIS region from 240 nm to 790 nm at a resolution of 0 2 nm to 0 4 nm The measured spectra are mainly used to derive ozone total column and vertical profile nitrogen dioxide bromine oxide water vapour oxygen sulphur oxide and other trace gases as well as cloud properties and aerosols The next figure shows a schematic representation of GOME optical layout A scan mirror 26 directs the light emitted from the Earth s atmosphere or the Sun diffuser 24 into the instrument The spectrometer splits incoming light into four channels 11 12 18 19 using a complex array of telescopes 5 25 prisms 4 6 and gratings 8 9 20 21 Detectors at the end of each optical path 13 to 16 collect information about the sign
47. lly the GOME 2 MetOp NRT and OL including reprocessed products in HDFS5 format are available at the DLR atmos FTP server ftp atmos eoc dlr de gome2nrt ftp atmos eoc dlr de gome2nt ftp atmos eoc dlr de gome2ol The products are organized in directories YYYY MM DD where YYYY is the year MM the month DD the day For requesting a FTP user account see 5 9 2 Additionally the NRT and OL products can be directly pushed to dedicated FTP servers located at the user s premises Following the O3M SAF strategy reprocessed products replace off line products in the local archive and FTP server The reasoning behind is that the reprocessed products are the best possible products and their quality is at least as good as the off line products 22 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 23 of 47 8 August 2012 5 9 Product Ordering 5 9 1 GOME ERS 2 GOME ERS 2 total column products are generated at DLR s D PAF on behalf of ESA cesa For ordering registration please contact ESA ESRIN EO Help Desk eohelp esa int Current and historical quicklook images as well as value added products generated by DLR are available at http atmos eoc dlr de gome 5 9 2 GOME 2 MetOp The GOME 2 MetOp total column products are generated at DLR in the framework of EUMETSAT s O3M SAF 03M SAF For inf
48. nated through different channels through direct FTP push to authorized users and through the EUMETCast broadcast system for near real time users through the EUMETSAT user services and by individual ordering and delivery through DLR s on line user services EOWEB Figure 2 4 4 Quality Control and Monitoring The quality of the OL products is controlled before they are archived and disseminated to the users A dedicated quality control tool integrated into DLR s data management system displays a set of parameters generated automatically by UPAS for each processed orbit The quality control tool performs limit checks and computes some statistics to show the confidence levels of the product and its evolution within time s17 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 18 of 47 4 5 Geophysical Validation The geophysical validation of the official GOME products is performed by independent partner organizations AUTH BIRA and FMI The validation is accomplished using ground based measurements available through the World Ozone and Ultraviolet radiation Data Centre ground based measurements from the NDACC network other satellite data as well as data assimilation techniques The validation results are publicly available on the Internet see section 5 9 4 6 User Services Information about data and s
49. olumns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 10 of 47 GOME 2 N O total column validation report SAF O3M IASB VR NO2 095 February 2011 R7 J van Geffen M Van Roozendael M Rix P Valks GOME 2 SO total column initial validation TN IASB GOME2 O3MSAF S02 01 1 November 2008 R8 M Van Roozendael N Theys N Hao P Valks GOME 2 BrO total column validation report SAF O3M BIRA VR BRO 091 January 2009 R9 N Kalakoski T Wagner K Mies S Beirle S Slijkhuis D Loyola GOME 2 H20 total column validation report SAF O3M FMV VR H2O 111 April 2011 R10 Delta Validation Report for ERS 2 GOME Data Processor upgrade to version 4 0 ERSE CLVL EOPG TN 04 0001 Iss Rev 1 0 December 2004 R11 Product Specification Document of the GOME Data Processor ER PS DLR GO 0016 Iss Rev 4 B December 2004 R12 GOME 2 Level 1 Product Format Specification EPS MIS SPE 97232 2008 R13 GOME 2 Products Guide EUM OPS EPS MAN 05 0005 Issue 1 0 February 2005 R14 HDF5 File Format Specification http www hdfgroup org HDF5 R15 BUFR Format Specification http www wmo int pages prog www WDM Guides Guide binary 1A html 10 DLR Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E Page 11 of 47 8 August 2012
50. ormation and access to all O3M SAF products please refer to the O3M SAF web page and help desk O3M SAF Web page http o3msaf fmi fi O3M SAF Helpdesk o3msaf fmi fi Additional information can be found in EUMETSAT s product Navigator accessible through the following link http navigator eumetsat int Current and historical quicklook images as well as value added products generated by DLR are available at http atmos eoc dlr de gome2 te DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 24 of 47 6 HDF5 Product Format Description The product content comprises the following groups e META_DATA e Product Metadata e GEOLOCATION e Date amp Time all retrievals e 4 Corner Coordinates amp Centre of Ground Pixel e Solar Line of Sight Zenith and relative Azimuth angles at TOA e Orbit information e TOTAL_COLUMNS e Total and tropospheric column amounts of the various trace gases with corresponding relative errors e CLOUD_PROPERTIES e Retrieved cloud properties e DETAILED_RESULTS e Geophysical parameters surface cloud and aerosol values e Vertical column slant column ghost column and AMF values with corresponding errors e Fitting diagnostics chi square RMS etc e Various subgroups for trace gas specific data e g O3 NO2Tropo SO2 6 1 Structure The data in the HDF5 fil
51. orssesseesorssoeessseeesseessseesse 22 5 8 L GOME ERS use nee RR 22 5 8 2 GOME 2 MetO Dieese aee ne aee ERE E Ee 22 5 9 Product Ordering er E E R i sa les a i a 23 59 L GOM FE ES a2 are Seca tet ot cok a satan en en she tacts ET 23 5 9 2 COME 2 MEIOD ee el 23 6 HDF5 Product Format Description usssssssosssossssnnssosssnnsssnnssnnsnsnssnsnsnssnsnnsssnsnnnene 24 6 1 Structure aA Re 24 6 1 1 Description of Common Items cccsccsssccsersesscssncsesccsncecssencesssenceessanes 26 6 2 META DATA Groups 2 20 ek 26 DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 6 of 47 6 3 GEQLOGATION Gro p u ustsehe I E EES PEENE EENE EEEN 29 6 4 TOTATECOLUMNS Gropius 31 6 5 CLOUD PROPERTIES Groups 2 04 leusckaklEnlegkalsikn 32 6 6 DETAILED RESULTS Group isseire reres a rnei raie e Ee aE ek 33 6 6 1 DETAILED_RESULTS O3 Subgroup esseesessessssessrsersssessrssresrersrsseessssesse 34 6 6 2 DETAILED_RESULTS NO2 Subgroip usiedsnike aachen 34 6 6 3 DETAILED_RESULTS SO2 Subgroup eeesersseessnessnnssnnesnnensnesnnnennnennnennnn 35 6 6 4 DETAILED_RESULTS H2O Subgroup eseeseoreseessnsssnnesnssonnesnnesnnnnnensnnne 35 6 6 5 DETAILED_RESULTS HCHO Subgroup eessseesssssessenssennenesnnnenennnnn 35 6 6 6 DETAILED_RESULTS CHOCHO Subgroup eeeeseesseesssessseessneesenennnnnn 35 6 7 DETAILED_
52. r on tropospheric vertical column density of BrO so2 float pixels Dobson Units Vertical column density of SO2 SO2_Error float pixels Error on vertical column density of SO2 H20 float pixels kg m Vertical column density of H2O H2O_Error float pixels Error on vertical column density of H2O HCHO float pixels molecules cm Vertical column density of HCHO HCHO_Error float pixels Error on vertical column density of HCHO OCIO float pixels molecules cm Slant column density of OC1O OCIO_Error float pixels Error on slant column density of OCIO CHOCHO float pixels molecules cm Slant column density of CHOCHO CHOCHO_Error float pixels Error on slant column density of CHOCHO for future use not yet implemented lt 3j DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 32 of 47 6 5 CLOUD_PROPERTIES Group In this group the main cloud properties of each pixel are stored Dataset Name Data Type Unit Description CloudFraction float pixels Cloud fraction CloudFraction_Error float pixels Error on cloud fraction CloudTopAlbedo float pixels Cloud top albedo 1 if clear sky CloudTopAlbedo_Error float pixels Error on cloud top albedo 1 if clear sky CloudTopHeight float pixels km Cloud top height 1 if clear sk
53. rest on Level 1 loading and other tasks The reprocessing of one year of GOME ERS 2 data can be done in just one day using 10 processing cores 4 1 GOME ERS 2 DLR has a processing chain for GOME ERS 2 NRT and OL total column products that is being used operationally since 1995 It includes data ingestion from level 1 to level 4 product generation quality control product archiving data dissemination and ordering The operational products from GOME are total ozone and NO using GDP 5 0 In GDP 5 0 the new GODFIT algorithm for total ozone developed by BIRA RTS DLR and the DOAS algorithm for NO are used See R2 and R3 GOME ERS 2 images and value added products produced at DLR are available at http atmos eoc dlr de gome 4 2 GOME 2 MetOp DLR has developed the operational processing chain for GOME 2 MetOp total column products The level 1b products are generated at the EPS ground segment in EUMETSAT R13 and received at DLR via EUMETCast DLR generates GOME 2 MetOp level 2 total column and cloud products using UPAS There are different modules for quality control and monitoring production control archiving and order handling The level 2 products generated at DLR are validated on a regular basis by the O3M SAF partner institutes AUTH BIRA and FMI The GOME 2 MetOp level 2 NRT products are disseminated primary with EUMETCast WMO GTS and internet The off line products are disseminated via Internet and media The ordering of produ
54. s Attributes attached to all data sets in this group are the same as those for the GEOLOCATION group This group contains the key trace gas total column information Data sets are arrays of size N where N is the number of ground pixels in the product granule All entries starting with the name of the trace gas are only included if the trace gas total column has been retrieved in which case it is included in the META_DATA MainSpecies attribute Dataset Name Data Type Unit Description 03 float pixels Dobson Units Total vertical column density of O3 O3_Error float pixels Error on total vertical column density of O3 O3Tropo float pixels Dobson Units Tropospheric vertical column density of O3 O3Tropo_Error float pixels Error on tropospheric vertical column density of O3 NO2 float pixels molecules cm Total vertical column density of NO2 NO2_Error float pixels Error on corrected total vertical column density of NO2 NO2Tropo float pixels molecules cm Tropospheric vertical column density of NO2 NO2Tropo_Error float pixels Error on tropospheric vertical column density of NO2 BrO float pixels molecules cm Vertical column density of BrO BrO_Error float pixels Error on vertical column density of BrO BrOTropo float pixels molecules cm Tropospheric vertical column density of BrO BrOTropo_Error float pixels Erro
55. ser Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 28 of 47 The next table contains metadata specific to the total column products Allowed Attribute Name Data Type Description a YP ipa Values NumberOfFittingWindows integer Number of fitting windows used in processing 1 M This table describes data sets containing information about the fitting windows a Allowed Dataset Name Data Type Description Wahine FWName string windows Names of fitting windows string FWLowerBound float windows Lower wavelength bound of a fitting window in nm 240 780 FWUpperBound float windows Upper wavelength bound of a fitting window in nm 240 780 MainSpecies string windows Name of the main reference species retrieved in this fitting string window VCDQualityIndicator float windows Percentage of flagged pixels see QualityFlags 0 2 in 6 8 2 for 0 100 this window 28 Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 29 of 47 8 August 2012 6 3 GEOLOCATION Group The GEOLOCATION group contains information for seven different points for the ground pixel denoted by letters A to G in Figure 5 MetOp GOME _ flight directio na m ae q P Yo So 9 at ground at Toa
56. spheric column products are e Nitrogen dioxide tropospheric column e Ozone tropospheric column e Bromide monoxide tropospheric column Additionally DLR provides the following cloud properties derived from GOME measurements e Cloud fraction CF e Cloud top albedo CTA and cloud optical thickness COT e Cloud top height CTH and cloud top pressure CTP DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 8 of 47 DLR provides near real time NRT off line OL and reprocessed products The NRT products have the same granularity as the input GOME data i e downlink or PDU and are made available and disseminated to the users within 2 hours 30 minutes of sensing The OL products are consolidated orbits from ascending node crossing to ascending node crossing and are available and disseminated to the users two weeks up to four weeks in case of GOME ERS 2 after sensing Additionally DLR provides reprocessed products for climate applications The complete GOME ERS 2 data record starting in 1995 has been reprocessed and validated on a regular basis using improved algorithms In the same way the complete GOME 2 MetOp data record starting in 2007 was already reprocessed and validated GOME ERS 2 and GOME 2 MetOp provide a unique data record of atmospheric measurements covering a time frame of around 25 years
57. straints on the current level 0 data dissemination Reprocessed GOME ERS 2 and GOME 2 MetOp level 2 products using the latest level 1 data and improved retrieval algorithms are available on a regular basis 5 5 Expected Accuracy The following table lists the GOME total column trace gases and cloud products provided by DLR together with estimated uncertainties Product Acronym Expected Accuracy Expected Precision Total ozone column 03 3 6 4 3 SZA lt 80 2 4 3 3 SZA lt 80 6 4 7 2 80 lt SZA lt 90 4 9 5 9 80 lt SZA lt 90 see R4 and R5 Tropospheric ozone column O3Tropo 20 40 20 40 Total NO column NO2 5 15 unpolluted 3 15 unpolluted conditions see R6 conditions Tropospheric NO column NO2Tropo 40 80 polluted conditions 40 80 polluted conditions gt 100 unpolluted gt 100 unpolluted see R6 Total BrO column BrO 20 50 see R8 10 50 Total SO column so2 50 100 SZA lt 70 20 50 SZA lt 70 gt 100 SZA gt 70 see R7 gt 50 SZA gt 70 Total H O column H20 10 25 see R9 5 20 Total HCHO column HCHO 50 100 polluted 20 50 polluted conditions conditions gt 100 unpolluted gt 100 unpolluted Total OCIO column OCIO 50 100 SZA gt 75 20 50 SZA gt 75 Total CHOCHO column CHOCHO TBD TBD Cloud fraction CF lt 10 lt 10 Cloud top height cloud top pressure CTH CTP lt 10
58. t 2012 and Cloud Properties DLR Page 26 of 47 6 1 1 Description of Common Items In the GEOLOCATION and TOTAL_COLUMN groups all datasets have a set of attached attributes These are shown in the table below Attribute Name Data Type Description Title string Description of the dataset e g Ozone total column Unit string Unit of the values in the array e g DU FillValue same as dataset Value in the array if actual data value is missing ValueRangeMin same as dataset Minimum value in this dataset present only when applicable ValueRangeMax same as dataset Maximum value in this dataset present only when applicable 6 2 META_DATA Group The content of the META_DATA group is shown in the following tables Allowed values for parameters required by EECF and UMARF are consistent with requirements given in A2 and A3 Allowed values specified in italics indicate any value of the given type e g string means that the attribute can contain any string within the UMARF size limit Allowed Values Allowed Values Attribute Name Data Type Description Typ P GOME ERS 2 GOME 2 Metop ArchiveFacility string Centre where the data is archived D PAF DLR OP O3DLR SatelliteID string Platform identifier mission and ERS 2 Mnn spacecraft StartOrbitNumber integer Orbit number at the start of sensing i e integer integer at the beginning of a dump
59. te Application Facility on Ozone and Atmospheric Chemistry Monitoring O3M SAF which is part of the Eumetsat Polar System EPS ground segment and is responsible in this project for the generation of total column amounts of the various trace gases and cloud properties which may be retrieved from GOME 2 MetOp level 1b products 3s DLR GOME PUM 01 Product User Manual for GOME Total Columns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 14 of 47 2 4 Measurement Scenarios Timelines and Instrument Modes GOME ERS 2 and GOME 2 MetOp follow in general the same operational scenarios see http gome eumetsat int http www eumetsat int EPSCalValExtranet Main GOMECalVal index htm for more details e Earth Observation Mode This mode includes nadir narrow static north polar south polar scanning measurements with various integration times depending on solar zenith angle This is the default mode for the day side Only the data acquired in this mode are used for geophysical retrievals e Calibration Modes This mode includes Sun Moon dark spectral light LED white light measurements Most of this calibrations are performed on the night side The effective optical throughput and the potential data rate for GOME 2 MetOp are much higher than those for GOME ERS 2 The default integration times for GOME 2 MetOp is 4 to 8 times smaller than those for GOME ERS 2 1 T
60. trieval retrieval retrieval retrieval retrieval retrieval retrieval If the retrieved total possible possible possible possible possible possible possible column is invalid it is and result replaced with the fill gt 0 value and this flag is set together with flags 1 and 2 1 2 Total column out of 75 700 0 5 10 0 1 5 10 10 0 100 lt 1 0 10 0 3 range DU mol cm mol cm 1000 DU kg m mol cm 100 10 Set if the total column mol cm retrieved for this ground pixel is outside the specified range 2 4 Large error in ESC lt 2 lt 50 lt 100 Not lt 50 Not Not Set if the ESC_Error applicable applicable applicable value of this ground pixel exceeds the specified threshold These flags give additional information about the quality of the total column retrieval If for example the fitting of the slant column does not succeed or in case of ozone the fitting results produce negative values flag 0 and also flag 1 and 2 is set to indicate this condition and the total column field will contain the fill value If the total column has been retrieved but is out of the specified range flag 1 is set If the associated slant column error exceeds a specific threshold flag 2 is set See VCDQualityIndicator in 6 2 on page 26 for the percentage of pixels which have been flagged as an overall quality indicator for the whole orbit 37 DLR
61. ument anni 9 1 2 1 Reference Documents essessesseesoessesseesorssreseesorssresoersrsseesoessrsseessessesseesserseeso 9 1 3 Abbreviations and ACTONYVINS ae een 11 2 GOME hstrumen east 12 2 1 Hoden on a ENT Na ae 12 PPA TON HA H o I nn be a enter 13 2 3IGOME 2 MelOp nennen 13 2 4 Measurement Scenarios Timelines and Instrument Modes uueee 14 3 Algor thm Descripti n sssss ssssssssesssssssrssssossossscssossssscosessss ssossssssessssrossasssssssessssssesosssesoi 15 3 1 SUMMATy a aha aa eie aa aA eaea AA Eha rE TOES Sra SASE ES 15 3 2 Trace Gas and Cloud Producer 15 A A OLET E T aaa E AEO E OAOA 16 A T GOME ERS 2 un een a a a a 16 BD GOME 2 MetOD ee a iE ee aare e tie eas EARE SARSA 16 4 3 Data Management en ie a en aan 17 4 4 Quality Control and Monitoring eeresonsssnssnnnessnnennnessnesnnnnssnnnsnnessnssnnnnssnnssnnensnnnne 17 4 5 Geophysical Validation en eseieneeseen en nl 18 2 6 LIS BE SEIVIC Eee ee era 18 5 Total Column Trace Gases and Cloud Products 20000000000000020000000222000000000000000 19 SEINE ie eier en a T 19 5 2 Geographical Coverage and Granularity eeeseesssesssensssesssnssnensnnnnnennnennenneennnnnenn 19 5 3 SpallallR esohit on ee seinen 19 5 4 Delivery Time 22 202882 eu 20 5 5 Expe ted Ackuracy rest enges Ea a Ea E EES 20 56 Product Formats ee e elle ia 21 5 7 Fil Names a 21 5 8 Product Dissemination seesseseeesorsseeseessrssesssessrssesssessees
62. umns of Ozone Iss Rev 2 E NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO 8 August 2012 and Cloud Properties DLR Page 36 of 47 6 7 DETAILED_RESULTS_GODFIT Group As the GDP 5 algorithm is different to GDP 4 an additional output section was introduced for each trace gas processed with GDP 5 For O3 DETAILED_RESULTS_GODFIT O3 it contains the following datasets layers 13 Dataset Name Data Type Unit Description O3Profile float pixels layers DU A priori O profile used in the retrieval of O TemperatureProfile float pixels layers K A priori temperature profile used in the retrieval of O FitPar1_O3 float pixels DU O3 column FitPar2_TemperatureShift float pixels K Temperature shift FitPar3_Albedol float pixels Internal closure parameter 1 FitPar4_Albedo2 float pixels Internal closure parameter 2 FitPar5_Albedo3 float pixels Internal closure parameter 3 FitPar6_Ring float pixels Fitted ring spectrum FitPar7_Undersampling float pixels Fitted undersampling FitPar8_WavelengthShift float pixels nm Fitted earthshine spectrum shift NumberOflterations float pixels Number of fitting iterations FittingRMS float pixels Final RMS of the fit O3Temperature float pixels K Fitted ozone temperature including T Shift GhostColumn float pixels DU Associated ghost column Covariance Matrix float pixels 8 8 Covariance and Correlation results matrix s
63. y CloudTopHeight_Error float pixels Error on cloud top height 1 if clear sky CloudOpticalThickness float pixels Cloud optical thickness 1 if clear sky CloudOpticalThickness_Error float pixels Error on cloud optical thickness 1 if clear sky CloudTopPressure float pixels hPa Cloud top pressure 1 if clear sky CloudTopPressure_Error float pixels Error on cloud top pressure 1 if clear sky CloudType integer pixels ISCCP cloud type classification 1 if clear sky 1 cirrus 2 cirrostratus 3 deep convection 4 altocumulus 5 altostratus 6 nimbostratus 7 cumulus 8 stratocumulus 9 stratus CloudMode integer pixels Mode in which cloud parameters have been calculated 0 normal mode 1 snow ice mode SurfaceAlbedo float pixels Surface albedo used for cloud retrieval PMDCloudFraction float PMDpixels Cloud fraction for forward scan PMD subpixels BI Product User Manual for GOME Total Columns of Ozone NO2 tropospheric NO2 BrO SO2 H20 HCHO OCIO DLR GOME PUM 01 and Cloud Properties Iss Rev 2 E DLR Page 33 of 47 8 August 2012 6 6 DETAILED_RESULTS Group The following table lists ancillary surface aerosol data and detailed processing results as stored in the DETAILED_RESULTS group Data sets see Figure 4 on page 25 are represented either as arrays of size N where N is the number of ground pixels in the product or as matrices of dimensions NxM for N the number of

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