Arcon User`s Guide
Contents
1. Sometimes a failure occurs during the transfer of the data from the controller to the Sun In this case a partial spool file results and there is no way to resurrect the data Recover will give you the option of deleting any such files and you should do so to avoid filling tmp with debris Appendix D Changing Image Directories You can change where your image data is stored on the fly with the command cl gt reset imdir data1 whatever Note that the trailing character is necessary This variable will be restored to its original default value when you log out of IRAF Also the values in the acquisition and reduction windows are independent and must be set separately To change imdir permanently and insure the two windows use the same value you must edit your login file as follows cl gt edit home login PEARL IMAGE LOGIN DEFAULT FILE Image pixel directory definition This is the ONLY place where this variable should be defined and changed setenv imdir data1 whatever lt Change this line as required You must then log out of Arcon and log back in for the change to take effect It is common practice at KPNO to set the IRAF image pixel directory to HDR pixels i e cl gt reset imdir data1 whatever This option assures that your pixels files will appear in a sub directory named pixels below the directory where the IRAF header files are created We urge the observer to adopt th2. G FSA Motor this client receives commands from the arClient and executes them The commands are sent to the Filter Shutter Assembly over a serial line The state of the FSA is also made available through the router All the commands needed to manipulate the FSA are available in the IRAF Data Acquisition window See section 4 0 for more information concerning the FSA A further word about image directories is in order at this point Your data acquisition machines has roughly 9 Gb bulk data storage On each of these there will be a directory data1 where this space is mounted At the start of your run all these disks will be cleared However you may have no trouble filling the available space in a few nights of typical observing From time to time you should use the command disks to see how much space is free on each disk Arcon uses the value of the IRAF environment variable imdir in order to decide where to write the pixel files for newly created images B 3 Shutting Down and Logging Out Before you log out for whatever reason you must first stop the Arcon related processes To do this bring up the background menu and follow the Arcon submenu Release the mouse button on Arcon Exit The processes that will be removed are all transputer arcon iraf and router executables and their corresponding windows IRAF Acquisition is setup to automatically disconnect upon exit or logout This allows for a clean download of transputer code when the Ar
3. For example to take sequences of 10 dome flats each in R 60s exposures U 10s V 5s and B 5s type cl gt doobs Exposure type object dflat sflat dflat Number of exposures to take in each filter 1 1 10 wheel one two or three one three list of filters in wheel3 R U V B List of exposure times 60 10 5 The following pictures will be taken Pictures Filter3 Exposure 100 109 R 60 110 119 U 10 120 129 V 5 130 139 B 5 Title for pictures Dome flats 21 June 95 3 0 The Parameter Files The observe command and its derivatives dark dflat etc have been purposely kept simple Additional flexibility can be achieved by modifying the options listed in three key parameter sets psets Many observers will only modify these psets once at the beginning of their run These parameters sets are G detpars This pset controls the fundamentals of how the CCD is read out i e binning gain regions of interest etc G obspars This pset controls the behavior of of observe and its derivatives G wheel1 wheel2 wheel3 This 3 in 1 pset contains Imager FSA filter information There is no equivalent pset for the Bench Spectrograph You should review these parameter files at the beginning of your run and modify them as necessary Many observers will never modify them again These parameter files can be listed by using the lpar command e g cl gt lpar obspars and may be edited using the parameter editor epar
4. 1 Ask the operator to adjust to secondary position about 30 microns 2 Start a 105 sec exposure in the desired filter 3 After 15 sec stop the exposure with the pause command 4 Ask the operator to move the telescope 20 arcsecs North and the focus 10 microns 5 Re start the exposure with the resume command 6 After 15 sec stop the exposure with the pause command 7 Ask the operatore to move the telescope 10 arcsecs North and the focus 10 microns 8 Re start the exposure with the resume command 9 Repeat steps 6 7 and 8 until the time is up 10 After the exposure is read out use imexamine to determine which images were the roundest and sharpest Ask the operators for assistance with imexamine if necessary This manual focus exposure procedure will be automated in the next major Arcon software upgrade 5 2 Maintaining the Imager Focus Because WIYN is a very lightweight telescope it mechanically responds quite rapidly to ambient temperature changes a 1 deg C change corresponds to about a 40 micron expansion or contraction The telescope often cools by 2 7 degrees C rapidly after sunset and then about 1 deg per hour for the rest of the night This corresponds to focus changes of 80 320 microns after sunset and 40 microns per hour after that Since a 10 micron change significantly defocuses the telescope compensating for these large changes is very important in maintaining focus To deal with this situation the telescope trusses
5. 20 Correlation width level 0 5 Percent or fraction of peak for width measureme shifts yes Compute shifts across the dispersion n dispaxis 2 Dispersion axis long slit only nspectra 1 Number of spectral samples long slit only ndisp 1 Number of dispersion samples slit1 5 Lower slit edge slit2 50 Upper slit edge n logfile logfile Logfile mode ql SPECFOCUS NOAO IRAF V2 10EXPORT feed indigo Sat 19 37 35 19 Sep 92 Best average focus at 1465 with average width of 1 41 at 50 of peak Average Over All Samples Image Focus Width d0001 imh 1430 2 86 d0002 imh 1440 2 23 d0003 imh 1450 1 66 d0004 imh 1460 1 44 d0005 imh 1470 1 44 d0006 imh 1480 1 89 d0007 imh 1490 2 54 Image d0004 imh at Focus 1460 The dispersion axis goes along columns dispaxis 2 and the slit covers columns 5 through 50 In addition there is a very sophisticated graphical display that helps in interpreting the results in the case of multiple sampling along the dispersion spatial axis read the help page for specfocus Currently specfocus may be loaded from the nlocal package I 3 Determining the gain and readnoise using findgain At CTIO it is common to measure the CCD gain and read noise whenever a CCD is installed on the telescope Rob Seaman has provided a useful script called findgain that will provide good estimates of the gain and read noise using two flat field exposures and two bias frames The frames sh
6. Full Well and Linearity to 200K e ADC Saturates before FW at Gain s 3 4 Select gain setting from the first column The current gain setting is 4 cl gt When you enter detpars you can edit the gain and when you enter q it will download the waveforms and change the gain To see if it has changed do another ccdinfo 3 2 obspars The parameter file obspars contains four distinct groups of parameters as shown below I R A F Image Reduction and Analysis Facility PACKAGE fsa TASK obspars ccdtype zero Exposure type npics 1 Number of exposures to take picture 1 Picture number of first exposure exposure 0 Exposure time title Test frame Title of picture autopic yes Generate picture number automatically POST PROCESSING PARAMETERS postpic display image Post processing command for single picture postseq Post processing command for sequences restart no Restart the server on every command SELECTING FILTER FOR EACH EXPOSURE setfilt one Query and set filters filtype instrument Type of filters to use SETTING FOCUS FOR EACH EXPOSURE setfocus yes Query and set focus foctype telescope Type of focus to use tempera 0 Telescope temperature basefoc INDEF Focus base value reftemp 0 Telescope temperature for base focus value tfrcoef Coefficients of Temperature Focus relationship PARAMETERS FOR FOCUS EXPOSURES nfexpo 7 Number of focus exp
7. chose a different script to be executed after the entire sequence from the one that is run after each exposure The restart option determines whether a new job is created after each exposure or not If restart yes then a separate process will be created This can cause too many processes within the IRAF environoment It can be controlled by using a task call postkill If restart no then you must not change the postprocessing scripts and you must remain in the current directory while taking data If you want to change either of these you must restart Arcon The third group of parameters controls the positioning of the Imager FSA filter wheel at the start of each exposure For the Imager FSA setfilt can be none not to move any wheel one to move only wheel one two to move only wheel two or three to move only the third wheel You will be prompted for the filter position when appropriate and the value you enter will be saved in the image header but you must wait several seconds for the filter to engage Remember that only one wheel is physically mounted in the FSA at any one time For the MOS Bench Spectrograph setfilt should be set to none Note that the filter position is never requested for exposures of type zero or dark The parameter filtype should always read instrument The remaining parameters will be used in the future for improved telescope instrument focus interaction For now keep setfocus no 3 3 wheel1 2 3 Thes
8. filter in position 1 name1 Harris_U Full name of filter in position 1 focus1 40 Focus value for filter 1 id2 B Short identifier for filter in position 2 name2 Harris_B Full name of filter in position 2 focus2 10 Focus value for filter 2 id3 V Short identifier for filter in position 3 name3 Harris_V Full name of filter in position 3 focus3 0 Focus value for filter 3 id8 drk Short identifier for filter in position 8 name8 Dark Full name of filter in position 8 focus8 0 Focus value for filter 8 Each group of three parameters corresponds to one slot in the filter wheel The parameter id is the short identification for the filter that you should type when prompted for a filter position by observe It should be short should be unique amongst the filters in the wheel and must not contain any white space or other weird characters One exception to the uniqueness requirement is that any empty positions may be given the same name e g clear but not a null or blank name provided you don t care which one is actually used The value of name is what will be recorded in the image header It can not contain the special character and blanks will appear as underscores in the header The focus correction feature is not implemented in the current version of the software The corresponding filter focus offset parameters should be set to zero for now 3 3 1 Setting Up the Imager FSA Without Taking a
9. have been wired with thermocouples which report the truss temperatures once every 10 secs We have determined empirically that G negative 1 deg C ambient temperature change cooler gt 40 micron focus change G positive 1 deg C ambient temperature change warmer gt 40 micron focus change This calibration is preliminary and will be refined as soon as possible The recommended procedure is to monitor the telescope temperature and adjust the telescope focus by the appropriate amount when a significant temperature change has occured Please ask the operator to show you how to monitor the telescope temperature One of the WIYN Project s highest engineering priorities is to automate this process so that it is transparent to the user 5 3 Filter Focus Offsets To first order the focus offsets between the broad band filters typically used at WIYN are determined by the filter thicknesses Thus these focus offsets are fixed with time We have not determined reliable filter focus offsets at this writing For now observers should pick a filter to be their baseline filter and then determine offsets to their other filters Such offsets should be reported to Dave Sawyer dsawyer noao edu and Dave Silva silva noao edu so we can begin to compile an offset database 6 0 Router Related Issues The MPGrouter is the source of all information from other WIYN specific instruments Special clients are written for each instrument These clients sen
10. telemetry information This includes the temperatures and voltages of the Dewar and CCD as well as the CHIP ID number COUNTDOWN This is the very small window with the very large font It provides a copy of the exposure time counter for the visually handicapped IRAF Acquisition This black colored window is one of two running the IRAF cl We recommend you type all data taking commands here so that your data taking and data reduction activities are well separated and don t interfere with one another IRAF Reductions This window colored an off white is the other IRAF window We suggest that normal IRAF commands used to examine or reduce your data are entered in this window The parameters used in this IRAF environment are NOT the same as those used when taking data in the Data Acquisition window IRAF Display Window Ximtool window will be used when displaying your images from IRAF This resides on the 2nd monitor The following 3 windows display messages associated with MPGrouter messages G icsInfo this client gathers and converts information from other instruments into IRAF format It will also create the MPG MSG icon which will report changes in the router when detected It s window is behind the Data Reduction window G Arcon Client arClient this client connects IRAF Acquisition Interface to the MPGrouter It gets information as well as sends it All FSA tasks from the FSA Arcon IRAF package send a command to this process
11. the root menu there is an ephemeris program xephem provided by Elwood Downey that will tell you the Julian date and times of sunrise sunset and twilight and many more wonderful things Do a Unix level man xephem for more information Appendix Z Revision History Version Date Author Comment 0 0 CTIO original CTIO Arcon User s Manual 0 1 6 1 95 Kennedy programmer pass 1 0 2 6 15 95 Kennedy programmer pass 2 0 3 7 2 95 Silva drs pass 1 shipped to Armandroff 0 4 7 12 95 Silva drs pass 2 incorp Armandroff comments shipped to Massey 0 5 7 21 95 Silva incorp Massey comments issued as beta 0 5 0 6 8 2 95 Silva incorp von Hippel comments fixed HTML refs added new appendices with misc IRAF information issued as beta 0 6 TODO 1 Add focus command information when available mid September 2 Beef up HTML internal referencing 3 Add active Table of Contents at top of document 4 Add obsinit information when it becomes available 5 Investigate document how to write observing scripts if possible 6 Investigate document Arcon CLI interface if possible 7 Add xtapemon stuff 8 Re review ICE manual for other tidbits to include
12. G epar l Edit the line plot parameters G epar s Edit the surface plot parameters Appendix I IRAF Miscellanea I 1 Analyzing Direct Focus Frames with kpnofocus Analyzing direct imaging focus frames has now been made fun and easy thanks to the new kpnofocus routine Simply run kpnofocus giving as input the name of the focus frame Next mark the top image in a multiple focus exposure using the g key You will have to wait a few seconds but you will then be presented with a plot of FWHM vs focus value Do this for a few stars and then exit using q This routine must be loaded from the nmisc package I 2 Focusing a Spectrograph with specfocus Frank Valdes has provided a very useful routine to aid us in determining the best focus of a spectrograph using a series of exposures of comparison lines The assumption is that the collimator or camera focus has been changed between each of the exposures The routine works by cross correlation and provides an easy measure of the full width at half maximum fwhm of the images In addition one can specify that the dispersion axis be broken into multiple samples to determine if the best focus is wavelength dependent and or the spatial axis can be broken into multiple samples to determine if the best focus varies across the spatial axis The simplest session of this program looks like this nl gt lpar specfocus images d imh List of images focus 1430x10 Focus values corwidth
13. G devices lists all the I O devices and Unix names G wfits write a FITS format image to tape or disk G rfits reads a FITS format image from tape or disk G mtexamine examines a magnetic tape and divulges interesting facts G files generate a list of files useful with wfits Appendix H Using ximtool The IRAF image display window is ximtool and combines the best features of Sunview IMTOOL with SAOIMAGE To load an image into the display simply type display image 1 where the 1 denotes display frame number 1 Up to 4 images can be loaded in frames 1 4 This command uses many defaults that sometimes need to be changed depending on the data and your needs Since the largest image that physically fits on the screen contains only about 1000 pixels on a side and since the WIYN CCDs are considerably bigger than this there is some trickiness to how you might want to display your data Basically you have two options G Set the buffer size set stdimage imtname to the full size of the image and display to it using display imagename 1 fill The fill will assure that each pixel in the image gets mapped into a single pixel in the display For our large chips however only a subsection of the image will fit on the displayed area Fortunately there is a panner box in the upper right hand corner of the window which will show you the entire image with a bright green box indicating which subregion is displayed on the main part of the
14. The WIYN Arcon IRAF Interface A User s Guide Dave Silva Diana Kennedy Phil Massey and Taft Armandroff Guide Beta Version 0 6 2 August 1995 drs Next Version ETA 1 September 1995 Please send comments corrections typos to Dave Silva silva noao edu for incorporation in next version 1 0 Introduction This is a user s guide for the IRAF based user interface to the Harcon and Arcon CCD controllers hereafter referred to generically as the Arcon controllers These controllers are currently in use at WIYN to control the Imager CCD a k a S2KB and the Bench Spectrograph CCD a k a T2KC The WIYN Arcon IRAF interface is also used to control the Imager Filter Shutter Assembly FSA a k a the Imager filter wheel This guide is maintained on line as a HTML document If you have a hard copy of this guide it is strongly suggested that you verify that the hard copy version number and revision date matches the on line version The on line URL is TBD This guide assumes a familiarity with basic IRAF usage and functionality Important This manual covers operation of WIYN Imager CCD and the WIYN MOS Bench Spectrograph CCD 1 1 Supplementary Documentation The observer might find the following documents useful G For an overview of IRAF we suggest you read A Beginner s Guide to Using IRAF by Jeannette Barnes G For a basic description of CCD reductions we suggest A User s Guide to CCD Reductions with IRAF by Phil Massey G For
15. You can contact Ed Carder if you need this service ecarder noao edu Appendix G Summary of Useful IRAF Commands for Quick Look This section has no pretensions of being a tutorial to IRAF but it is our intention to call your attention to or remind you of some of the more useful IRAF commands for examining your data Use the IRAF help command and or poke around to become familiar with these commands G diskspace check remaining space on disk G dir lists the files in current directory G imcopy copies an image or subraster of an image to another image G imrename renames an image G imdelete delete images G imheader list image headers G hedit edit the header parameters of an image G hselect list specific items from the image headers G display displays an image on the ximtool window G imexamine general image analysis utility row and column plots radial profiles surface plots contour plots image statistics G imhist histogram the pixel values in an image G imstat detailed statistics on an image G implot plot rows columns and averages of these G splot plot a row from an image with spectral analysis tools G imarith arithmetic operations between images G imcombine combines images such as averaging or median G allocate allocates a tape drive G deallocate deallocates a tape drive necessary in order to logout G devstatus reveals what IRAF thinks about the tape
16. an 32 Number of overscan pixels detname S2KB Detector identification mode ql Observers will wish to examine and perhaps modify the following parameters G Gain This parameter is a CCD gain index which is discussed further in Section 3 1 1 G Xsum This parameter controls how many input on chip pixels are summed in the X direction to form one output pixel in X direction G Ysum This parameter controls how many input on chip pixels are summed in the Y direction to form one output pixel in the Y direction The next four parameters establish the CCD Region of Interest ROI to be read out G Xstart This parameter sets the first column to be read out G Ystart This parameter sets the first row to be read out G Xsize This parameter sets the number of columns to read out G Ysize This parameter sets the number of rows to be read out The ROI parameters shown in the example above correspond to reading out the entire CCD area MOS Bench Spectrograph note there is no reason to ever readout less than the entire CCD during normal MOS Bench Spectrograph observations as it is beneficial to record the area beyond the spectra to monitor scattered light levels This extended area is ultimately used to correct for scattered light see the Hydra User s Manual for more details The preflash field is not relevant to WIYN applications The extend xskip1 xskip2 xtrim1 xtrim2 ytrim1 ytrim2 and amplifiers should be le
17. ced by number of pictures in sequence type replaced by exposure type title replaced by exposure title examples display image 1 display last image imcombine sequence combine all images in sequence hedit image i_title title type change image title to include type quotes must be escaped postproc image the nominal default KPNO postproc script Warning no check is made of the command syntax or it s validity or that the necessary packages are loaded until it is executed by the cl Errors in the execution may produce incomprehensible error messages from IRAF To clear this out type flpr An information sideline from within IRAF if you cd to the directory containing your headers you can do the following types of commands imexamine lastpic display and examine the last exposure imcombine lastseq combine last sequence These are special functions that accept file input The lastpic has the last exposure name in it Similarly the lastseq has a list of the last sequence taken in it The restart parameter in obspars will determine how the postprocess is run If it is set to yes then a new postprocessing job is created for each new image This can create too many IRAF background processes If too many jobs are active the task postkill can be used to clear them out If you do run out of batch slots you will be warned that it was not possible to execute the postprocess command If restart is set to no then yo
18. con is used again Appendix C What to do if things go wrong C 1 SUN in a strange State If you have a suspicion that the system is somewhat flakey you can verify that everything is cleaned up after exiting Arcon by typing pearl NexUp No match No match No match If you get No match three times in a row as above all is well If instead you see something like pearl NexUp root 2227 0 0 3 0 2664 844 p6 S 17 32 0 05 muxnex arcon 2229 0 0 6 172 160 p2 S 17 32 0 00 arsh c0e2 arcon 2228 0 0 0 144 0 p2 IW 17 32 0 00 arsh c0e2 dev nexc0 Nomatch rwrw 1 arcon 0 Jul 13 17 32 tmp xpim2229 1 rwrwrw 1 arcon 0 Jul 13 17 33 tmp xpim2245 1 then there are some leftover processes which you must kill by hand as follows pear1 kill 9 2227 2229 2228 In this command the list of numbers after the 9 are the pid s of the leftover processes as displayed by NexUp The files with names like tmp xpim2229 1 are the spool files used by Arcon to transfer data to the Sun If any of these are owned by you and have a size other than zero the number just before that date then they may contain your missing data See Appendix C section 3 for information on how to retrieve this It is common to see a few zero length files as shown in the example but these can be ignored Now you can exit from the windowing system and log out completely by moving the mouse to a blank area of the screen then hold down the right mouse button and select exi
19. d out status and instrument specific information and subscribe to other instrument information that has been made available The maximum frequency of updates to this information is on a per second basis The information should be within a 2 second range of accuracy unless messages have been dropped Dropped messages are generally due to a CPU being too busy to read them The MPG MSG icon contains the most recent detected status of the MPGrouter It is only noticed during the picture taking phase where the process of getting and reformatting header information is done The process is called icsInfo It subscribes to FSA information as well as the TCS data streams The warnings that it issues are 1 If the TCS information is not being updated between pictures you will get a message indicating that you need to have the operator check to verify that messages are being sent to your client 2 If the MPGrouter comes down and you have been able to reconnect successfully then you will see a message saying that you can continue to take data 3 If the MPGrouter comes down but you are unable to reconnect then you will see a message that you will need to restart Arcon when the MPGrouter has recovered 4 If the MPGrouter is not running when you bring up Arcon then you will see an alert that tells you to Restart Arcon when the MPGrouter is running You can iconify this message by clicking on the CONTINUE button You can collect data if the MPGrout
20. e imh will be in your current directory until the complete image is available Then it is renamed to image name imh If you requested that observe take only a single exposure the message observation finished will appear in the IRAF interface window as soon as the readout is complete things are then ready for you to start another exposure If instead you requested a sequence of several pictures the next exposure will start automatically You may immediately examine or process the resulting image even though the sequence is not complete Note that the pictures remaining counter in the status window shows how many exposures remain in the sequence Once the final picture has been read out the message sequence finished will appear in the IRAF interface window Should you miss the end of sequence or end of exposure message note that the CCD is idle and things are ready for you to initiate new exposures whenever the top line of the status display reads CONTINUOUSLY_ERASING 2 1 2 The MOS Bench Spectrograph The MOS Bench Spectrograph CCD Arcon system behaves in nearly the identical way to the Imager CCD Arcon system with two notable exceptions G The Bench Spectrograph Arcon system has no interface to any Bench Spectrograph hardware expect the actual CCD system All Bench hardware is controlled from the Bench Spectrograph Graphical User Interface the bsgui G The Bench Spectrograph Arcon system supports one additional image t
21. e parameter sets are not used with the MOS Bench Spectrograph These parameter sets are used with the Imager FSA The FSA has three 3 different filter wheels but only one 1 filter wheel can be inserted and used at a time The FSA software can sense which wheel is actually in use and will warn the observer if the observer specifies the wrong filter wheel The wheel1 2 3 psets allow the observer to specify the name and focus offset for each filter position in each wheel This allows filters to be referred to by name instead of having to remember which filter is in which slot in which wheel They also contain the corrections to the telescope focus which must be made when each filter is used In the future these values will be used to automatically adjust the telescope focus when filters are changed For now these values are merely stored in the pset file for later reference When editing instrpars you can access these parameter sets by using the arrow keys to move down to the correct line and then type e Alternatively you can edit these parameter files by typing e g cl gt epar wheel1 OR cl gt wheel1 Make certain that no extraneous characters appear in the value field of wheel1 wheel2 or wheel3 after exiting if they do just enter a null string as the value Whichever method you choose you will see something like this I R A F Image Reduction and Analysis Facility PACKAGE fsa TASK wheel1 id1 u Short identifier for
22. er is not running but you will not get TCS FSA Hydra or Bench Spectrograph headers Furthermore FSA commands entered through the IRAF interface will not be executed This causes long delays waiting for commands to timeout Appendix A Arcon Software Task Cribsheet Summary Data taking commands G observe Take one or more exposures prompting for type G dark Take one or more dark exposures G comp Take one or more comparison exposures Bench CCD only G dflat Take one or more dome flat exposures G object Take one or more object exposures G sflat Take one or more sky flat exposures G zero Take one or more zero exposures G focus Take a focus frame G more Take more exposures of the previous type G doobs Take multiple exposures in multiple filters Exposure Control Commands G abort Stop exposure and do not readout detector G stop Stop exposure and readout detector G tchange Change exposure time G pause Pause current exposure G resume resume paused exposure Parameter Sets G obspars Observing parameters G detpar Detector parameters G instrpars Instrument parameters Rarely used G wheel1 filter info parameters for Imager FSA wheel1 G wheel2 filter info parameters for Imager FSA wheel2 G wheel3 filter info parameters for Imager FSA wheel3 FSA Setup Control G instrument Generic instrument control based on instrpars pset Loaded packages G arcon Automa
23. ft set to their default values The fields pixsize nxpixels nypixels noverscan and detname are only informational They can not and should not be changed The messages you will see when the waveforms are downloaded will look very similar to these Preflash time changed from 0 000000 to 0 000000 There are no regions of interest defined There is one region of interest defined ROI Lower Left Corner of Pixels Upper Right Corner x y x y x y 1 1 1 2048 2048 2048 2048 Regenerating waveforms xp run waveforms Harcon1 9 Recompiling waveforms xp run waveforms Harcon1 9 csh xp run macro wdl s2kb WDL revision 2 18 Binning factor 1 Pixel readtime 15 us Binning factor 2 Pixel readtime 18 us Binning factor 3 Pixel readtime 22 us Binning factor 4 Pixel readtime 26 us cp s2kb nex xp run macro Harcon Stis2048 Observe nex Suspending the sequencer Reloading new waveforms 3 1 1 Setting the Gain It is possible to change the slope time of the Integrater usually erroneously referred to as the gain which determines the number of e ADU the readout noise and the readout time This can be changed by entering detpars and changing the gain entry to one of the possible options The recommended WIYN CCD gain values are G Imager S2KB 2 8 electrons ADU gain index 3 G MOS Bench Spectrograph T2KC 1 7 electrons ADU
24. gain index 4 For most Imager projects and all MOS projects we strongly urge the observer to adopt the above gain values Nevertheless the observer can determine the available gain options and current settings using G ccdinfo For the Imager CCD S2KB ccdinfo produces the following output cl gt ccdinfo gain 4 Gain setting preflash 0 Preflash time seconds xsum 1 pixels summed in X direction ysum 1 pixels summed in Y direction xstart 1 Start of ROI in X ystart 1 Start of ROI in Y xsize 2048 Size of ROI in X ysize 2048 Size of ROI in Y extend separate Method of extending ROI to include overscan xskip1 0 X pixels to skip at start of overscan xskip2 0 X pixels to skip at end of overscan xtrim1 0 X pixels to trim at start of data xtrim2 5 X pixels to trim at end of data ytrim1 2 Y pixels to trim at start of data ytrim2 4 Y pixels to trim at end of data amplifiers lr Readout amplifiers to be used pixsize 21 Pixel size in microns nxpixels 2048 Detector size in X nypixels 2048 Detector size in Y noverscan 32 Number of overscan pixels detname S2KB Detector identification mode ql Table of gain values Detector S2KB 2048 x 2048 21 um pixels dcsT GAIN Read_Noise Gain Readout Time us e e ADU sec 1 3 1 14 7 5 88 2 5 2 9 4 3 104 3 8 3 8 2 8 129 4 15 4 7 1 5 185
25. icture will pan to center up on the cursor You can also pan by simply grabbing the green outline in the panner box using the left mouse button and moving it to outline the part of the image you would like The controls on the upper right allow one to flip the image left and right up or down change frames the frame number is displayed between the two fat arrows and best of all open a control pannel left most icon The control pannel allows you to turn the coordinates box and panners on and off flip blink and much much more If you find that you have somehow mysteriously added little green boxes on your image you can get rid of these by placing the cursor in such an extraneous box holding down the right most mouse button and selecting Destroy Appendix G Using imexamine The imexamine task provides some of the most powerful diagnostic quick look tools within IRAF If an image that you wish to examine is already displayed in the ximtool window simply type imexamine Wait patiently without moving the mouse and a blinking round cursor will appear on the display If you lose patience try pressing the L5 key without moving the cursor Place the cursor over a star and strike the r key and you will be presented with a radial plot of the star along with the values of a fit to the stellar profile The last number displayed is the FWHM in pixels quite useful for determining the best focus Other very useful commands include l for
26. ilter wheel G rebootshutter will reboot the shutter The observe command will automatically prompt the user for the filter and will send the exposure time and the chosen filter to the FSA Note if the MPGrouter is down these commands will not work through the Iraf Acquisition Window They will either timeout or fail 5 0 Focusing the Imager 5 1 Establishing the Initial Imager Focus There are two ways to establish the current Imager focus wavefront curvature sensing and a manual focus exposure The former method is recommended for the start of the night or when changing to a filter with an unknown filter offset The latter method is quicker during the night when the observer is trying to fine tune the focus in a sequence of exposures using the same filter or when changing to a filter where the filter offset is known Wavefront curvature sensing is easy but time consuming it takes about 15 30 minutes This is often time well spent if you ve become really confused often the case in these early days Here s the easy part just ask the duty telescope operator to do this Remember to tell them what filter to use Manual focus exposures are a little more involved but often faster Some coordinating with the telescope operator is still needed The basic idea is to take obtain multiple images over a range of focus on the same CCD frame Note that 10 microns is about the right minimal secondary movement amount Here s a simple procedure
27. into the IRAF Acquisition window CL It will take several minutes for the hardware and software to be ready When it finishes the message Connecting to the controller will appear followed by Data reader restarting and several messages associated with the downloading of the detpars waveform Wait until you see the cl gt prompt in the data acquisition screen before continuing abort focus pictitle setshutter ccdinfo initfilter postarch sflat comp initshutter postkill shutter connect instrpars preview stop dark instrument rebootfilter tchange detcomp more rebootshutter teloffset detparm movie recover telpars detpars object resume wheel1 dflat observe rtdpars wheel2 disconnect obspars setdetector wheel3 doobs pause setfilter zero expshutter pflat setrtd cl gt Loading the instrument package automatically establishes the connection to the controller as indicated by the Connecting to the Controller message hidden amongst the package menus Exiting from the package with bye or usually inadvertently CTRL Z breaks the connection NOTE You can not take data if the connection is broken Once the initialization procedure has been completed your screen should appear somewhat like Figure 2 Figure 2 shows a picture of the Arcon Data Acquisition Environment The key windows for taking data with Arcon identified by the names given in their title bars are as follows Arcon CONSOLE As its name implies this window
28. is directory structure style Appendix E Postprocess There is an option to automatically perform a IRAF process on the newly created image This is fondly known as postproc To choose this option set obspars postpic see Section 3 2 to postproc image If you have chosen this option via the obspars parameters at the end of the picture creation you will see the message Running post processing command and the picture will automatically be displayed in the ximtool window There is another option to run a process after the entire sequence It works in a similar fashion and is activated by setting the obspars postseq parameter to the script you want executed Note if you want a special task to be executed it must be defined as an IRAF task in the usual way See the appropriate IRAF documentation for further assistance You will then have to set the obspars postpic or obspars postseq parameters as desired Examples of setting the obspars parameters postpic display image 1 Post processing command for single exposures postseq imcombine sequence Post processing command for sequences In the above example for a single exposure both the postpic and postseq scripts will be run The postseq script is always run The possible substitution strings are image replaced by name of last image readout sequence replaced by list of images in sequence picture replacec by picture number of last image readout npics repla
29. it unscaled IEEE standard reals Change these at your own risk G blocking fac The default 0 results in maximum blocking 10 for both Exabyte and 9 track tapes If you are planning to read the data with a non IRAF FITS reader you may want to reset this to 1 otherwise leave it at 0 for maximum tape writing efficiency In order to check to see what is on the tape you can list the titles quite easily Simply do a cl gt rfits mtb 1 999 make short old to see what s there To direct this output into a file you can add a tapelist to the end and then you can print that list on the printer by a simple lprint tapelist Alternatively you could choose to read a single file back onto disk to examine cl gt rfits mtb 15 junk make old will create an image with the original name Note that even if you specify old you must still give the name of a legal temporary file in the output file position i e junk in this example If the same image name already exists on disk you should instead use old to create an image named junk or whatever you wish As you write your tape you will get a file by file account of what is going on the tape When you come to the end of the tape you will find that there is a message saying that the file was NOT completely written to tape An easy way to continue at this point is to edit your at file to remove the names of the files that were successfully written to tape Rewind the tape with rew mtb mou
30. making a line plot at the position of the cursor and c for making a column plot at the position of the cursor Other useful cursor strokes are shown below G r Make a radial profile of the star near the cursor The FWHM will be the last number shown in the plot G a Print FWHM without showing the radial plot G c Plot the column nearest the image cursor G l Plot the line nearest the image cursor G j Fit a 1 d Gaussian in the x direction centered near the cursor G k Fit a 1 d Gaussian in the y direction centered near the cursor G m Print the statistics in a box around the image cursor G e Make a contour plot of a region around the image cursor G h Plot the histogram of a region around the image cursor G s Make a surface plot of a region around the image cursor G c N Plot column N when in graphics mode G l N Plot line N when in graphics mode G naverage M ave M columns or lines during plots G x Print the x y z values of the pixel nearest the image cursor G z Print a 10 by 10 grid of pixels around the image cursor G o Overplot G g Go to the graphics window from the ximtool window G i Return to the ximtool window from the graphics window G Print help G q Quit imexamine G epar r Edit the radial profile plot parameters G epar c Edit the column plot parameters G epar e Edit the contour plot parameters G epar h Edit the histogram plot parameters
31. n Exposure Instrument If you want to say move the filter wheel without taking a CCD exposure use instrument This task will prompt you for positions for each motor and move it to that position just as observe does However instrument obeys the setfilters and setfocus parameters in obspars and hence will only move those motors you have enabled More often than not it is precisely those motors you have disabled in obspars that you want to move For instance you may normally have filter2 disabled setfilters one but want to switch to a filter on a different wheel and switch back at the end If you want to override setfilters for a single invocation of instrument proceed as follows cl gt instrument setfilters two Filter in wheel two u cb The setfocus parameter can be overridden on the command line in the same way 4 0 FSA Package The FSA Filter Shutter Assembly Arcon Iraf package allows the user to enter commands through the IRAF interface to manipulate the FSA Most observers will never have to use these commands The following commands are available G initfilter will reinitialize the filter wheel G setfilter set filter wheel to position N G initshutter will reinitialize the shutter G setshutter will set the shutter to a particular mode either normal xfer or fast these depend on the exposure time G expshutter this sends the exposure time to the FSA and changes it s mode G rebootfilter will reboot the f
32. nt the new tape and then re run wfits remembering to set newtape yes NOTE If you do write additional files to an old tape one containing useful data but which had previously been removed from the drive make certain that the software IRAF and Unix is aware that the tape has been rewound before starting to write to the tape or your old data may be overwritten To safegaurd against this possibility we suggest that you ALWAYS swap tapes by first cl gt deallocate mtb or mtc or Physically swap tapes cl gt allocate mtb or mtc or F 2 Safe Taping We remind the observer that s he and s he alone is responsible for keeping one s bits safe We recommend the following before deleting any data from disk 1 Each night write data to whatever media you like using wfits 2 Read the tape using rfits mta make old to substantiate everything is there 3 Deallocate the drive remove the tape and stick it under your pillow 4 Make a second copy of your tape This tape could be an accumulative copy of the data throughout your run Check this tape with rfits 5 Only now delete the data from disk if necessary F 3 Save the Bits Transparent to the observer all CCD images are automatically archived onto Exabyte tapes This program should not encourage lax taping procedures and we strongly emphasize the need for the safe taping procedures above But if you ever do need to recover a night s worth of data take heart
33. on Negative contrast black stars on white background is realized by moving the mouse to the upper half of the ximtool window positive contrast is obtained by moving the mouse to the lower half of the window Higher contrast is achieved by moving the mouse vertically away from the center The image is made darker blacker by moving the mouse to the upper left negative contrast or lower right positive contrast The most extreme displays are usually obtained when the mouse is in one of these two corners You can learn the approximate pixel location of the mouse by reading the value in the box at lower right The intensity is also displayed there If the intensity read out has a or next to it the pixel is either brighter or fainter than the display command has scaled the data To change the scaling from the default use the display command as follows cl gt display image 1 zscale zrange z1 0 z2 2000 to set the scaling is now set to 0 2000 rather than the automatic scaling printed out previously when display was executed You may also zoom the picture using the middle mouse button Press the button once and the image will move in an attempt to center up on the mouse cursor Press it again without moving the cursor and the image will zoom up a factor of 2 Pressing the middle button 3 more times will zoom the picture up to a factor of 4 8 and back to 1 normal If you move the cursor while zoomed and then press the middle button the p
34. or by simply typing the name of the parameter set e g cl gt epar obspars OR cl gt obspars To change a value in either case move the cursor up and down with the arrow keys until you are on the correct line and then simply type the new value followed by amp LT RETURN amp GT When done editing the parameter file type q On the WIYN workstations cntrl Z works as well 3 1 detpars The detector parameters are set in the pset detparm par The task detpars will automatically bring up the detparm par file for editing and download the appropriate binary executables to the Arcon controllers a k a download the waveforms The detector parameters are IRAF gain 4 Gain setting preflash 0 Preflash time seconds xsum 1 pixels summed in X direction ysum 1 pixels summed in Y direction xstart 1 Start of ROI in X ystart 1 Start of ROI in Y xsize 2048 Size of ROI in X ysize 2048 Size of ROI in Y extend separate Method of extending ROI to include overscan xskip1 0 X pixels to skip at start of overscan xskip2 0 X pixels to skip at end of overscan xtrim1 0 X pixels to trim at start of data xtrim2 5 X pixels to trim at end of data ytrim1 2 Y pixels to trim at start of data ytrim2 4 Y pixels to trim at end of data amplifiers lr Readout amplifiers to be used pixsize 21 Pixel size in microns nxpixels 2048 Detector size in X nypixels 2048 Detector size in Y noversc
35. orecast Are you wondering how likely it is going to remain clear or are you considering packing it in for the night The wdisplay task in the nlocal package may help you decide what to do Three times an hour 24 hours a day a new GOES weather satellite picture in one of three wavelength bands visible IR and a water vapor narrow IR band is downloaded It is fun easy and informative to display the last four images and quickly blink between to see what s coming your way or leaving you alone Simply run cl gt wdisplay ir four to load the last four images into your ximtool window You may have to select the menu item FitFrame Hit CNTL F repeatedly to make a little movie Further information can be gleaned from the help page If you would like to compare your guessimate with that of an expert you can also easily retrieve the most recent weather prediction Put the mouse in a blank area of the screen and select Weather Forecast under Astronomer Tools You ll be presented with a map of the US with little dots on it place the cursor near Tucson and click You can check the weather back home the same way of course Appendix J Other Nifty Things There is a prototype automatic logging routine that constructs a TeX version of the observing log Instructions may be obtained via anonymous ftp to ftp noao edu cd kpno manuals binary get ccdlogs2 ps Z Comments should be directed to tlauer noao edu Under Astronomer tools in
36. osures refis middle Reference is first middle or last exposure freferen 5000 Focus value fdelta 30 Focus increment focmode auto Focus mode shtype detector Shift type f_stepsize 0 Focus stepsize in arc seconds f_direction north Focus direction for telescope fnrows 30 Focus number of rows to shift mode ql nargs 0 The first group of parameters are used for all exposures It is not necessary to set the values of most of these since they are prompted for as needed The values appearing in obspars are simply the values entered the last time observe was run The parameter autopicnum determines whether observe will prompt you for the running picture number picture which forms part of the name of your images on disk The value of picture is always incremented after each exposure If autopicnum yes the default the automatically derived value will always be used and you will not be prompted If autopicnum no you will be prompted for a new value of picture for every exposure the automatically derived value being supplied as the default In either case you can reset the sequence by just changing the value of picture in obspars Warning Note that picture will get out of step if you abort an exposure or sequence the value used will be the one which would have been appropriate if the exposure or sequence had completed normally The second group of parameters controls what task or script is run for postprocessing One can
37. ould not have been processed or combined in any manner The astronomer should specify a section of the image over which the flat field is relatively constant Additional details can be found by reading the help page for findgain The routine currently lives in the nproto package I 4 Determining the shutter correction time with findshutcorr The actual exposure time of your image may differ by some fraction of a second from the requested exposure time due to the fact that no shutter can open or close instantaneously If you are attempting absolute photometry or spectrophotometry and plan short enough exposure times that you are worried about the shutter correction there is a simple routine in IRAF called findshutcor which will help you evaluate the correction Written by Rob Seaman the routine determines the shutter correction from a series of flat field exposures of varying lengths 1 sec 20 sec say You must be careful not to have saturated on the longest exposures of course and the frames must have been processed for removing the overscan level but not flat fielded In taking the data one must also carefully take into account the possibility that the flat field lamps intensity may drift slightly with time i e a good exposure sequence might be 1sec 20 sec 2 sec 2 sec 20 sec 1 sec The findshutcorr routine currently lives in the nlocal package I 5 Checking the weather without leaving the dome wdisplay and picking up the latest f
38. r it may also be that the Sun has gotten irremediably confused in which case the rather drastic step of rebooting it may be needed If this is necessary contact observer support They can show you how to reboot the Sun safely cleanly and without having to know the superuser password C 3 What to do if Your Picture Doesn t Show Up Recover Sometimes Arcon will successfully transfer your data to the spool file on tmp but the picread program which converts this to an IRAF image will fail Usually there is an error message but you should be suspicious that this has happened if the exposure completes normally but you can t find the output image The command recover will help you to retrieve your valuable images in such cases It searches tmp for any spool files owned by you and for any of these that are complete will show the FITS header and ask if you want to recover the image or not If you reply yes then picread will be run to convert the xpim file to an IRAF image A single spool file occasionally contains more than one image In this case recover will list how many images are present but will only show you the header of the first All images will be recovered if you tell the program to go ahead Spool files are not removed from tmp until successfully converted by picread However we suggest you run recover immediately if you encounter this problem so that you don t forget later and so that tmp doesn t get filled with unprocessed raw data files
39. reate a FITS image long_header no Print FITS header cards short_header yes Print short header bitpix 0 FITS bits per pixel blocking_fac 0 FITS tape blocking factor scale yes Scale data autoscale yes Auto_scaling mode ql The crucial parameters are G iraf files This refers to the image name s that you wish to save e g a0002 a0005 if you wish to only save those two files Instead you can also substitute an at file here such as shown in the example An at file is simply a text file that contains the names one per line of each image You can easily create such a file by files imh gt savethisstuff G fits files This refers to the tape drive you wish to use In the case of the Exabytes or DATS this can simply be the same as the device name that you used in allocate G newtape This is as you may well imagine a critical parameter to get right If you want to start at the beginning of the tape writing over any data that might be present then answer yes to this otherwise it will search for the end of the data on the tape before writing G bitpix scale and autoscale By leaving these values at their default values bitpix 0 scale yes autoscale yes the data will be written to tape in such a way that you are never losing any precision Nothing will be scaled and raw CCD data will be written as unscaled twos complement 32 bit integers while floating point data will be written as 32 b
40. s the title in the IRAF image header G filter in wheel one two three the required filter Note that filters can be specified by name rather than by their position in the filter wheel the way this translation is set up will be described in section 3 3 The filter wheels will be moved to the selected positions before continuing The filter used will also be noted in the image header This information is not requested for exposures of types zero and dark for which the filter is irrelevant Note that the FSA only holds one 1 filter wheel at a time although three filter wheels exist The FSA is smart enough to sense what filter wheel is physically in place and will warn the observer if the wrong filter wheel is requested However if the wrong wheel is requested during an observe setup the error described in the next paragraph will occur Warning If the filter fails to move to the correct position a warning message will be printed and the current observe command will abort Note that in each parameter query you will be supplied with a default value which you can accept by simply hitting lt RETURN amp GT these values are just the previous entries If you make a mistake or change your mind you can abort the command during the parameter entry stage by typing CTRL C having done so you should always enter the command flpr to clean up the hidden mess Once the exposure has started it can be terminated using the abort command see Note tha
41. serves as a console for Arcon While you are observing you will see many messages appear here only some of which will be repeated in the IRAF acquisition window This window is hidden behind the Data Acquisition screen and if it is distracting you can close it But don t quit from it In the event that something goes wrong the diagnostic messages appearing in this window may tell you or at least us what happened Arcon STATUS This very important window gives several lines of information summarizing the status of the controller the instrument and any ongoing exposures see Figure 2 The first line shows what the controller is currently doing if you have just brought the system up it should read CONTINUOUSLY_ERASING indicating that the CCD is idle and is continuously running the erase cycle if it doesn t chances are something went wrong in the initialization and you should seek help During exposures this line should read INTEGRATING and should change to READING as the CCD is read out Other messages which may occur will be described later as appropriate Just below the status line are counters showing the number of seconds left in the current exposure the number of exposures left in the current sequence and during read out the number of buffers of data successfully transferred to the Sun Also shown are parameters of the current exposure such as the title picture name etc Finally for the Harcon the bottom line contains some important
42. t from the menu which will appear C 2 Warm Starts Rather more often than we would like something or other happens which causes the system to hang requiring that the software be reloaded Before doing so it is worth testing to see if the problem is confined to the IRAF interface layer by proceeding as follows cl gt flpr This flushes out any brain damaged executables locked into the IRAF process cache Having done this test to see if the problem has gone away by taking a zero frame If this fails or if the status window has stopped functioning then the problem is probably in Arcon itself and it is best to reload the software from scratch This takes very little time There are 2 options for restarting Arcon 1 If the CPU is not maxed out then Bring up the background menu follow the Arcon submenu and release the mouse on Arcon ReStart 2 If the CPU is pegged then Bring up the background menu follow the Arcon submenu and follow the CPU Pegged Options Release the mouse on Iraf Arcon Kill After all processes disappear follow the CPU Pegged Options menu again and release on Iraf Arcon Start This will start new Arcon and Iraf processes If the CPU is still pegged then follow the instructions for logging out and then log back in C 2 2 If All Else Fails Just once in a while a problem will occur which just refuses to go away even when you reload the Arcon software This may be due to a hardware failure Howeve
43. t the observe command terminates as soon as the exposure starts and you can enter other commands in the IRAF Acquisition window Additional Arcon commands entered at this point can inadvertantly modify the current active exposure This feature is a bug which will be corrected in later release of the software In the meantime observers are urged not to issue additional Arcon commands while an exposure is on going In addition we suggest that all data testing and reduction commands be issued in the IRAF Data Reduction window not the IRAF Data Acquisition window When the exposure finishes the CCD will be read out The first line in the status window will change to READING and the buffers read counter will indicate the number of buffers of data successfully transferred to the Sun The data is initially written in the controllers internal format to a spool file on tmp but it is automatically converted into an IRAF image within a few seconds of the exposure finishing The message Image written to disk appears as soon as this process is complete and shows you the name of the new IRAF image This name is derived from the exposure type by appending a running number controlled by the obspars parameter set described in section 3 2 which is automatically incremented after each exposure The image header will be in the current directory when the observe command completes and the pixel file will be located in your imdir A temporary file Timage nam
44. the definitive overview of MOS Hydra we suggest the soon to be revised Hydra User s Manual by Sam Barden amp Taft Armandroff All three of this supplementary documents can be obtained by contacting Jeannette Barnes jbarnes noao edu 2 0 Taking Data 2 1 The Only Command You Really Need To Know observe 2 2 1 The WIYN Imager All data taking can be done by using a single command observe The observer will be prompted for all the information necessary for controlling the exposure An Imager observe dialogue looks like this with user input in bold cl gt observe Exposure type zero dark object dflat sflat focus zero object Number of exposures to take 1 1 Exposure time 0 0 1000 Title of picture bias 16 07 93 HH80 81 SII Filter in wheel one U I Image obj107 written to disk Observation finished Running post processing command postproc obj107 Information requested includes G exposure type can be zero sometimes referred to as bias dark object dflat sflat or focus Note that when selecting from a list of options like this you may enter any unique abbreviation Focus sequences are not supported in this release of the software G number of exposures to take a sequence of this number of pictures all having the same parameters will be taken G exposure time is in seconds and will not be requested in the case of exposures of type zero G picture title will be included a
45. tically loaded main Arcon package G FSA Automatically loaded FSA Filter Shutter Assembly package Imager only G connect Task to make connection to detector controller automatically done by FSAetc G disconnect Task to break connection to detector controller automatically done on bye from FSA Appendix B Logging in and Logging Out B 1 Computers and Peripherals Figure 1 shows a picture of the WIYN control room Figure 1 shows the control room at WIYN Sam Barden the Hydra Project Scientist is sitting in front of the monitor for oatmeal the Hydra Sun workstation The Imager Sun workstation pearl is in the far corner near the empty blue chair to Sam s right Sam is using Oatmeal and next to him on his left is Vanilla another data acquisition computer used with the Bench Spectograph and Hydra B 2 A Guided Tour of the Arcon Windows The Imager Harcon system is run from the pearl workstation while the Bench Spectrograph CCD is run from the vanilla workstation The current observer logins and passwords are posted on the machines When the observer logs in an OpenWindows environment is loaded and the Arcon IRAF interface software is executed automatically Several windows will come up including a IRAF Data Acquisition and a IRAF Reduction window The controller software will automatically be down loaded as well as any appropriate CCD controller parameters specific to the installed chip Also the FSA IRAF package will be loaded
46. u need to remain in the directory that you started in when using postprocessing Also the postprocessing script can not be changed unless you restart Arcon after the change is made This option loads in the script initially and uses the files lastseq and lastpic in the current directory to perform the desired script s Appendix F Writing Your Data To Tape F 1 Making a FITS tape using wfits So now that you have some data you probably want to save it to tape using the IRAF command wfits First you must allocate a tape drive At WIYN there are both Exabyte and DAT tape drives The Exabytes are known as mtb and the DAT drives are known as mtc You can find these names printed on each drive unit you can also run the IRAF command devices to list both the IRAF and Unix names of all the I O devices on the mountain Do an cl gt allocate mtb to allocate the Exabyte tape drive at WIYN use mtc for the DAT drives Since all of the KPNO IRAF data acquisition systems subscribe to IRAF networking you can in fact use any tape drive in any dome although you need to check with the appropriate astronomer if you want to use someone else s tape drive be nice To allocate a drive elsewhere you might do something like a cl gt allocate lapis mtb The parameters for wfits are iraf_files savethisstuff IRAF images fits_files mtb FITS filename newtape yes Blank tape bscale 1 FITS bscale bzero 0 FITS bzero make_image yes C
47. window The advantage of this is that when you see a pixel it is really a pixel and you can easily evaluate things like bad pixels and columns The disadvantage is that you cannot see the entire image at once but must move the panner box in order to change the region being shown G Set the buffer size set stdimage imtname to something small enough to fit on the screen but display to it using display imagename 1 fill The fill means that every pixel in the image will contribute to the intensity of each pixel in the display but not 1 1 In other words if you were displaying a 1024 x 1024 image into a frame buffer that was 512 x 512 large using fill would be the same as averaging ajacent pixels The advantage of this is that you will see the entire frame without having to move the panner box the disadvantage will be that even if you zoom you will not be seeing actual individual pixels Phil Massey recommends option 1 for spectroscopic applications but 2 for direct imaging One of the other authors prefers to do both using 2 see the full frame in the Data Acquisition window so that images will be automatically displayed showing the full field but setting the defaults in the Data Reduction window using 1 so that each pixel can be cherished by redisplaying an image from there Once the image is loaded you can adjust the brightness and contrast parameters by moving the mouse in the window while holding down the right hand butt
48. ype comp for comparison spectra exposures Appendix C Section 2 2 3 Other Commands For Taking Data In addition to observe there are specific commands to take one or more pictures of each type G dark Take one or more exposures of type dark G dflat Take one or more exposures of type domeflat G object Take one or more exposures of type object G sflat Take one or more exposures of type skyflat G zero Take one or more exposures of type bias G comp Take one or more exposures of type comp Only supported by the Bench Arcon system Except of course for the exposure type these commands take the same parameters and prompt for them in the same order as does observe Apart from saving you entering that one extra parameter use of these commands allows one to set default parameter values and also select which parameters are prompted for according to picture type Another useful command is G more Take one or more exposures exactly like the previous exposure If you type cl gt more you will not be prompted for the number of exposures as one might expect but rather a single exposure will be taken which more often than not is what you actually wanted to do However if you type cl gt more 10 ten more exposures will be acquired Note to ICE users mores does not work A very useful task when you want to take Imager calibration exposures or exposures of the same object in various filters is G doobs
Download Pdf Manuals
Related Search