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WHIRC User`s Manual v1.13

1. amplitude or the 2 x 2 grid scripts The canned scripts default to a Rotator Offset of 0 0 Although we feel that the pupil ghost can be removed from the flatfields WHIRC User s Manual Version 1 13 2013 October 18 46 during data reduction conservative users may prefer to use the 2 X 2 grid scripts which avoid the center of the array e Science fields with pointlike targets One may use the same scripts as for the standard stars with the same caveat about avoiding the pupil ghost at the center of the array For faint sources requiring many individual observations 1 e 1f integration times are limited by background one may either use a large dither pattern 5 x 5 or repeat a small grid say 2 x 2 many times In the latter case it is good practice to offset the grids by small amounts arcsec to achieve better sampling over the array e Moderately extended targets If the source is extended but lt 1 arcmin or so one can still dither the source on the array but using spacing sufficient to ensure there is no overlap of the source on adjacent dither positions so one can still use the source observations for generating a sky frame e Very crowded fields or extended targets One will still use a grid pattern dither on the source field but 1t will also be necessary to obtain observations of a nearby but sparse field to generate the sky data See Fig 5 27 fora WHOMP script which combines a small amplitude dither on the source field
2. This option will query the PAN to determine if the fiber link is up or down In the latter case the task will reload the link driver on the whirc pan computer If the link is up the task will test the link for junk bytes and clear them One should then carry out the DHE Loop Test as a check e Reset MOP This will reset the MOP GUI 5 6 Making an Observation Script Using the WHOMP The WHOMP 1s a very versatile tool for generating observing scripts which can incorporate a combination of small dither motions larger amplitude motions for mapping and offsets to distant sky positions when working on extended targets Each of these three motions is generated by a separate portion of the WHOMP GUI Dither Dither motions are small amplitude typically 10 50 arcsec used to move the field around on the array so that all locations in the target field are sampled by different pixels on the array This ensures that bad pixels or other defects do not repeatedly affect the same region of the field and 1s used for generating sky frames on relatively sparse fields The dither motions should be larger than any target in the field unless it 1s so large that actual sky observations are required but small enough to maximize the area common to all of the observations The default dither setting on bringing up WHOMP is 1x1 a single point so one must select the dither pattern using the slider bars Map Mapping motions are a significant fraction of
3. FDBG panImgBufferInit create 1 DEG panDaemon registered 1183 new commands FDBG panDaemon Nxt Command is 1213 DEG panDaemon After detInit status 0 DBG In Child Entering panTriggerExp 0 DBG In Parent Calling pantaptureData process 27582 DBG Entering panDataCapture 0 pan ProcAlg whirc pan anSaver whirc pan DBGK Starting panSaver FDEG panMemInitNotDaemon attached _panMemP Oxb7f08000 FDEG panSaver finbufsize 17580800 FDEG panImgBufferInit create 0 FDEG panSaver After detInit status 0 FDBGA Entering panDataSaver FDEG Entering panGetImgParams DBG Leaving panGetImgParams istat 0 FDEG dhsUtilOpenConnect fprows 2144 FDBGA dhsUtilOpentonnect fpcolummns 2050 FDEG dhsUtilOpenConmnect fpSize 17580800 DBGe imgServerControld lsize 2008 lshmid 108134468 serverImage DEG Starting panProcAlg DEG panMeminitNotDaemon attached _panMemP Oxb7f2a000 DEG panImgBufferInit create 0 DBGk panDataProcAlg entering 0 Figure 5 6 Successfully initialized PAN window on the observer s monitor WHIRC User s Manual Version 1 13 2013 October 18 18 5 Single click on the Start MOP button to bring up the Observer s Interface window a Fig 5 7 the MOP debug log window b Fig 5 8 the MOP status window c Fig 5 9 the WTTM client window d Fig 5 10 the WHIRC Detector Biasing window e Fig 5 11 and a ds9 display window f
4. x y coordinates of the guide star in the WHIRC image are used as input to WTTM to acquire the guide star a Am PA Xx WTTM Client Offset arcsec EA pA Move to Paxel Ra no Current Aalis Corigin pixel se To E Y GO Dec 0 0 Y 0 dJ Guided Dithers Engineering GUI dJ WITH Enabled Figure 7 5 The WT TM Client GUI which appears during MOP initialization Same as Fig 5 10 The currently relevant WTTM Client commands are WTTM Enabled The WHIRC MOP interface must know which method to use for guided observations The default state is for the client to come up with WTTM Disabled When using the IAS guide probe for offsetting guiding it should be left in this state with the button grey To enable WT T M fast guiding and offsetting click on the WTTM Enabled button and the small radio button will turn red when WTTM is enabled Guided dithers This is used to control the way in which WTTM executes scripted offsets Guided dithers are enabled disabled by clicking on the Guided Dithers button with the red radio button indicating an enabled state o Guided dithers disabled This operates MOP scripts in the same way as with the IAS guider in which the WTTM guiding is disabled prior to a telescope offset the telescope offset and corresponding error sensor probe motion occur independently then the WTTM guiding is re enabled to recapture the guide star This is the most efficient and recommended method of using WITM o
5. 0 0 150 Oct 26 13 26 48 whirc_bias check Bias Tel_08 vloRowEn 0 968 req 1 0 0 150 oct 26 13 26 48 whirc_bias check Bias Tel 01 iSlew 3 118 req 3 12 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel_ 16 vrstUc 0 976 req 1 0 0 150 A c Click on the Bias Detector button which should turn green Bias the detector by clicking on OK in the query window This is the final step in biasing the detector Ifthe detector temperature is above 100 K a warning message will be displayed and the detector will not be biased NOTE THE DETECTOR ANA y WHIRC Detector Biasing Temperature 0078 500 K Voltages ok E Power Detector W Bias Detector Reset Temp Monitor Update Voltages AAO N Det 26 13 26 47 whirc bias check Bias Tel_ 9 50 A Oct 26 13 26 47 whirc bias check Bias Tel C 150 Oct 26 13 26 47 whirc bias check Bias Tel_ Bias detector 150 loct 26 13 26 47 whirc bias check Bias Tel 150 pce 26 13 26 47 whire_ bias check Bias Tel_ D Oct 26 13 26 48 whirc_bias Powering VIRGO Oct 26 13 26 48 whirc_bias check Bias_Tel_ OK 150 Oct 26 13 26 48 whirc_bias check Bias_Tel yA loct 26 13 26 48 whirc_bias check Bias_Tel 10 vnUc 0 956 req 1 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel 17_vpUc 3 484 req 3 5 0 150 Oct 26 13 26 48 whirc bias check Bias Tel 00_iIdle 2 270 req 2 21 0 150 loct 26 13
6. 0076 952 K 0100 000 fitert_motor 0077 071 K d 0000 000 fiter2_motor 0077 042 K k k t cold plate 0076 703 K tolerance 0000 010 K k k k k heater_power 0000 245 watts max_power 0006 220 watts temp errar uvu uw fK Command Panmeters a P roportional EL pa Haatar Off aa hiterential Cool Down Set Polnt Goal K warm Up Toles ance K iate k min Figure 5 4 Display of the Temperature Control tab on the WHIRC Engineering GUI WHIRC User s Manual Version 1 13 2013 October 18 16 d Temperature status shows temporal plots of temperature for the various temperature sensors installed in WHIRC One can select plot parameters including which sensor temperatures to plot sampling period and temperature window This temperature status window 1s particularly important for monitoring the warmup and cooldown procedures whire Bog Filbers 1 Tumperabare Control Teanpershee Slalu __ MIEN Sense Only Temperature Status o Aa e e SRA Seg 2K 17 1320 Segre DR 17 SNM Siege OR 17 ARAN Tare secundis Rj j Phut Chenents Temp Range autu Prol Width 1 huur Sinple Periud 10 secumts M track ond Figure 5 5 Display of the Temperature Status tab on the WHIRC Engineering GUI WHIRC User s Manual Version 1 13 2013 October 18 17 4 Single click on the Start Pan button This opens a VNC session to the whirc pan computer which i
7. 2013 October 18 25 5 2 Short Summary of Normal WHIRC Start Up Sequence 1 Observer If wiyn 2 screen is empty double click on WHIRC icon to bring up menu a Single click Stop PAN button to clear out any ongoing processes 2 Ask OA to single click the WHIRC Engineering window and check Temperature Control window Filters window Temperature Status window Wait until OA says to proceed ao of 3 Observer Single click Start PAN button a Wait for all 4 windows to open b Be sure there are no errors first read error in panSaver is OK c If errors click Stop PAN button then Start PAN button again 4 Observer single click Start MOP button MOP debug log window appears make sure there are no errors MOP status window appears MOP control panel appears Wait until Filter status windows are green WTTM client window appears may be iconified if WI TM not used Check that red button on Enable WTTM button is not lit if IAS guiding is used WHIRC Detector Biasing window appears ds9 display window automatically opens 70 hoe ao op 5 Observer single click PyRAF button a PyRAF window opens 6 Observer Check in WHIRC Detector Biasing window Temperature button is green detector temp 78 5 K Voltages OK button 1s green Power Detector answer yes Bias Detector answer yes At this point Biasing window may be iconified NOT CLOSED E ae ee 7 Observer Single click WHOMP button optional a WHOMP GUI
8. 26 48 whirc bias check Bias Tel 02 vCas 2 991 req 3 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel_06_wpD 3 958 req 4 0 0 150 Oct 26 13 26 48 whirc bias check Bias Tel 07 vloReset 0 037 req 0 0 0 150 Oct 26 13 26 48 whirc_bias check Bias Tel 11 vdetCom 0 992 req 1 0 0 150 Oct 26 13 26 48 whirc_bias check Bias _Tel_08 vloRowEn 0 968 req 1 0 0 150 loct 26 13 26 48 whirc_bias check Bias_Tel 01_iSlew 3 118 req 3 12 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel_ 16 vrstUc 0 976 req 1 0 0 150 Ms Figure 5 15 WHIRC Detector Bias window during the Power Detector top panel and Bias Detector bottom panel procedures d After successfully biasing the detector the window looks like the following all green lights and one 1s ready to observe WHIRC User s Manual Version 1 13 2013 October 18 24 AOG Xx WHIRC Detector Biasing Temperature 0078 500 K Voltages ok E Power Detector W Bias Detector Reset Temp Monitor Update Voltages Oct 26 13 29 42 whirc bias check Bias Tel 08 vloRowEn 0 960 req 1 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 01 _iSlew 3 118 req 3 12 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 16 vrstUc 0 976 req 1 0 0 150 Oct 26 13 29 42 whire bias Biasing VIRGO detector
9. Guided dithers enabled MOP scripts command the WTTM to maintain guiding and to drag the field using the error sensor and X Y stage This can be useful for small offsets using guide stars near the faint limit but is very slow The motion occurs in 1 5 arcsec steps each taking 1 25 s to execute thus a 15 arcsec offset requires 12 5 s Offset Dither This is used to offset the telescope under WTTM error probe control This should be used for executing a MOP script multiple times on a deep field with small offsets between each dither pattern or for simply offsetting the WHIRC User s Manual Version 1 13 2013 October 18 56 telescope under WTTM control Enter the desired offsets in the RA and DEC fields then click the Dither button Asking the OA to offset the telescope in the normal manner will result in losing the WITM guide star Move to pixel This moves the WTTM X Y stage to the equivalent pixel location on the WHIRC detector Engineering GUI This opens up a window to set several low level WT TM parameters and 1s not generally for use by the observer 7 2 3 WTTM Operation Observers planning on using WTTM should come prepared with guide star information for each of their fields as well as realistic expectations of the improvements which WTTM may provide Dither sequences should be planned to accommodate relatively frequent focus updating which may be necessary if the temperature is changing and the image quality is good
10. Success WM explector 64 000 lt 0 00000040 gt lt ise ppxSetAvP expvector 65 socket got gt OK ppxSetAVP Success Wh expVector set to 65 0007 ise ppxSetMode da4 mod socket got gt OK ppxSetMode Success 4 Restored attribute values from Monsoon fcefo _whirc dad mod ise ppxGetAvP expvectorst socket got 20K ppxbetAWP Success 44 explector 65 000 lt 0 00000041 gt lt ae ise ppxSetAvP explector 65 eee 1socket got 20 ppxSetAVP Success Mh expllector set to 65 000 lt ise ppxSetMode da4 mod socket got gt OK ppxSetMode Success Sh Restored attribute values from Monsoon i cfg_whircrdad mad lt Figure 5 9 The MOP status window automatically loaded with the MOP WHIRC User s Manual Version 1 13 2013 October 18 20 d The WTTM client window This will be used in conjunction with WTTM operation once this is supported If one is not using WITM the window can be iconified to reduce clutter However if IAS guiding is desired the Enable WTTM button on the WTTM client window must be OFF red radio button not lit This should be the default condition of the window Xx WTTM Client Offset Carcasa i ree Ra T Current Asis origin pixel x p Dec 0 0 10 J Guided Dithers Engineering GUI J WTTM Enabled Figure 5 10 The WTTM Client GUI also automatically loaded with the MOP Select Disable WTTM to permit IAS guiding Hove to Pixel e The WHIRC Detector Biasing Window This will
11. The averaged lamp off images are subtracted from the lamp on images to remove common signals such as hot pixels and thermal or stray background light While it is possible to generate sky flats from the science images in the H and Ks filters the photometric performance of such flatfields has not been verified One concern is that the pupil ghost Fig 3 3 which is particularly prominent in the Ks filter has a different spatial structure in raw sky images than in the dome flats probably resulting from different contributions of local and sky thermal emission in the two cases Long term monitoring of dome flats has shown them to be spatially stable to within 1 or so whereas no equivalent monitoring of the stability of sky flats has been carried out Observers are free to use sky flats except for taking darks they come for free from the observations but we recommend taking dome flats as a backup The low sky background in the J and narrowband filters generates insufficient signal for a high S N flat so sky flats in these filters will require twilight illumination WHIRC User s Manual Version 1 13 2013 October 18 50 6 2 5 Darks Unless one 1s generating sky flats from science data or twilight observations there 1s no need for dedicated dark observations with WHIRC The process of image subtraction for both science and dome flat observations also removes any dark current or fixed bias contribution from the result However we
12. as usual Problem The mean value of the first image in a dither sequence appears lower than the others and the sky subtracted image shows a palmprint like structure Solution This appears to be a consequence of the way the detector is operated The magnitude of this effect will depend on the flux level frame time and time interval between frames In between exposures the detector is operated in an idling mode where it is continuously read out to keep the voltages on the pixel near the bias level WHIRC User s Manual Version 1 13 2013 October 18 62 Switching suddenly to an infrequent readout will result in a change in the power dissipation and thus temperature on a time scale much shorter than the detector temperature regulation can handle The palmprint artifact shows up as a region of elevated dark current in long darks and is believed related to a known photo emitting defect on the array as a result it is likely to be more sensitive to changes in temperature than the rest of the array We may be able to develop post processing techniques to minimize the effect of this but the only way to possibly eliminate it under the current microcode is to wait a significant time between individual frames which would decrease the observing efficiency 8 3 Guiding or Dithering Problems Problem When executing a scripted dither sequence the telescope does not offset Solution This usually indicates a communication problem
13. be used to power and bias the detector once the OA has verified that the instrument and detector temperature are within safe limits This procedure which was previously carried out by the OA has been moved to the observer terminal for convenience and to eliminate a socket connection which 1s believed to cause unreliable operation When this window appears it will check the detector temperature and system voltages and issue an error message if any is out of the tolerance range Ifa voltage is out of range or the detector temperature is greater than 100 K the Bias Tool will not power or bias the detector ae fF X WHIRC Detector Biasing Temperature 0078 501 K Voltages ok Power Detector _j Bias Detector Reset Temp Monitor Update Voltages Whirc_bias check Bias Tel 05 vhiReset 3 976 req 4 0 0 150 EN Oct 26 13 22 26 whirc bias check Bias Tel 09 vn0ut 2 465 req 2 5 0 150 Oct 26 13 22 26 whirc_bias check Bias_ Tel_10 vnUc 0 956 req 1 0 0 150 Oct 26 13 22 26 whirc_bias check Bias Tel 17 vpUc 3 484 req 3 5 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_00_ildle 2 270 req 2 21 0 150 Oct 26 13 22 26 whirc bias check Bias Tel 02 vCas 2 991 req 3 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_06_vpD 3 958 req 4 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 07 vloReset 0 037 req 0 0 0 150 Met 26 13 22 26 whire bias check Bias Tel 11 vdetCom 1 000 req 1 0 0 1
14. by WHOMP will contain the source information within the observe command and this will overwrite any observer entry on the MOP The syntax of the command 1s observe lt File name gt lt integration time gt lt Exposure type gt lt frames gt To set up the script for a particular target one may substitute the desired lt File name gt and lt integration time gt at each occurrence in the generic script In general the Exposure type Object and frames 1 so these would be edited less frequently It 1s also possible to edit the script to use the entries from the MOP which may be the most convenient approach observe gui_image_name gui_exp_time gui_exp_type gui_num_frames WHIRC User s Manual Version 1 13 2013 October 18 43 5 7 3 WHOMP Caveats Seripts created by the WHOMP generally begin with an offset to the most southwestern point of the map dither and step in increasing RA and then DEC through the dither and map positions Sky observations generated by the script follow the dither sequence at each map point e g offset to map point 1 execute target dither sequence offset to sky execute sky dither sequence offset to map point 2 execute target dither sequence offset to sky Note that the same sky position is used for all of the map points A typical grid map will then end at the northeastern point and the script will conclude with an offset motion to the origin Some observers may wish to edit WHOMP scri
15. filter opens Figure 5 3 Display of the Filters tab on the WHIRC Engineering GUI WHIRC User s Manual Version 1 13 2013 October 18 15 c Temperature control panel used for controlling the warmup and cooldown of WHIRC The detector has a heater that keeps the detector temperature stable within 10 mK when cold ensures that the rate of warmup and cooldown of the detector is no more than 1 K per minute and ensures that the detector temperature 1s above that of the other components in the instrument to prevent condensation of any outgassing constituents on the detector The Monitors window lists a snapshot of the temperatures for the different components in the system The Status window shows the current LakeShore temperature controller parameter values The Commands window is used to command the start of warmup and cooldown sequences reset the temperature control and turn off the heater The Parameters window 1s for entering the PID coefficients and temperature set points in order to modify the control response of the LakeShore heater controller as a function of the measured detector temperature Opluarrs Fillers lemperalure Cunt lemnperadwe Status WIYN Staff use Only Monitors Status delecior UV TS 494 stale IDLE vir gu ures YRS OK sw_err uplical bemsh NN 120 Ke s lpuinl ana SAN He rad shield NAI RANSK setpoint qoal ANTAR SANK colimator Na NMN rate an nan min camera 0076 709 p 0500 000 motor_plate
16. normally The OA will advise whether the WTTM probe is following the offsets properly If observing a science field where the IAS guider is required either because of the lack of a bright guide star or a large guided offset script push the WT TM Enabled button on the WTTM Client GUI and verify that the red radio button turns off WHIRC User s Manual Version 1 13 2013 October 18 57 8 0 Troubleshooting As with all instrumentation things occasionally go w on amp In particular the WHIRC system architecture and its interaction with WIYN is complex Figures 4 1 and 4 2 so there are opportunities for problems particularly on the initial night of an instrument block when the instrument and its associated computer are being reintegrated into the system Depending on the previously scheduled instrument this involves powering up the motor controller and DHE the temperature controller would have been turned on during the cooldown and powering up the whirc pan computer All of these steps should occur in the afternoon of the first night so they should not impact the typical user but potential related problems will be covered for completeness We anticipate that the use of the Mac Min1 platform wiyn 1 and incorporation of the detector biasing into the MOP will reduce the frequency of startup issues This list is not complete as we still encounter new operational problems Moreover a particular failure mode can have more than one cause so
17. of options Do not type an entry in this field d Set Exposure time Type or use arrow radio buttons to change the exposure time to the desired value NOTE the exposure time input should not be smaller than the minimum time for the particular readout mode which is noted at the bottom of the MOP For safety we recommend minimum integration times of 4 s for Fowler 1 and 16 s for Fowler 4 e Change the Number of frames or repeated observations if desired This is particularly useful for flatfields or darks where multiple observations are necessary f Type in the name of the object in the target field The ra and dec fields are updated automatically from the Telescope Control System h The File name dark 100s in Fig 5 18 is the basename of the FITS file created by the observation One may set this by changing the File name and or the number 57 The number will automatically index after an exposure is taken If you set the File name and the extension to that of an existing image the MOP will ask if you wish to overwrite after completing the exposure Spaces in the filename should now be OK 1 Set the directory into which the FITS files are written after the observation 1s complete When the MOP is brought up it will automatically update the data directory to the current date in the format lt dd gt lt Month gt lt yy gt j One may turn off the automatic display into ds9 by unchecking the Automatic display button The MOP default
18. opens Refer to the Troubleshooting Manual section 8 in the event of problems during startup or observing WHIRC User s Manual Version 1 13 2013 October 18 26 5 3 Shutting Down WHIRC At the end of the night the MOP PAN and WHIRC Bias tool interfaces should be closed The WHIRC Engineering GUI should be left running on the OA terminal to permit monitoring of the WHIRC temperatures Follow the procedure below to safely shut down WHIRC 1 Using the MOP put the filter wheels into the OPAQUE filter position 2 Unbias the detector using the WHIRC Detector Biasing window If it has been iconified it can be brought up from the PAN pull down menu on the MOP a Unbias the detector by clicking on the Bias Detector radio button A window will pop up and ask you if you want to unbias the detector Click OK to proceed with unbiasing b Unpower the detector by clicking on the Power Detector radio button A window will pop up and ask you if you want to unpower the detector Click OK to proceed with unpowering the detector c Close the WHIRC Detector Biasing window Xx on top left corner 3 Exit the MOP by pulling down the File menu and selecting exit NOTE Closing the Detector Biasing window may also close the MOP automatically Closing the MOP prior to the Detector Biasing window will close that window as well 4 Close the PAN session by clicking the Stop PAN button This will close the window and terminate all of the PAN backgroun
19. pattern is repeated many times with small differential offsets between each pattern to obtain better sampling over the detector pixels In extremely crowded fields or on extended objects subtending an appreciable fraction of the WHIRC field it is necessary to supplement the on source dithering with similar dithered observations of a nearby but sparse field to generate the sky frame While these additional observations reduce the overall duty cycle they are necessary to obtain good sky subtraction and quality results 6 2 WHIRC Strategies 6 2 1 Dithering Strategies As noted in Section 5 the MOP is able to execute either a single observation typically for setup and focusing or scripts which offset the telescope in between observations One may use one of a number of canned scripts std_ obs those generated by other observers or new scripts designed using the WHOM P sections 5 7 and 5 8 The dimension given in the canned scripts refers to the differential separation not the total extent so the std 5x5 l0O0arcsec obs script executes a 5 x 5 dither pattern centered on the initial telescope position which is 400 arcsec on a side ft is advisable to review a script using a text editor to ensure that it really carries out the desired telescope motions The file names of observer generated scripts may not accurately describe their function e Standard Stars One may use the canned 5 point scripts with relatively small
20. process and this appears to have almost eliminated this particular failure mode One circumstance under which these DHE hangs occur is following the use of the Abort button to terminate an exposure or a script Use of the Abort command is often an invitation to problems Aborting a single exposure even 1f done successfully can often result in a premature readout of the next exposure suggesting that not all of the processes were properly terminated In general an Abort Script command will complete the current integration and then exit from the script The telescope position will not return to the initial location With a long script there 1s no reasonable alternative to aborting but one must be prepared to recycle the system 1f there are problems A hangup during the Read Net stage of the Countdown Window accompanied by an error message box about an unexpected input could indicate a bad entry in one of the MOP fields It 1s possible to inadvertently enter unwanted characters into a MOP field by moving to a new window to enter a command and the new window does not become activated by the mouse over If a bad entry is found correct and proceed with observing Hangs have also been seen with the Countdown Window displaying DatalO This can suggest that the data disk may be filling up Do a df and check for disks which are at or near 100 capacity There is not always an easy solution to a hangup of this sort
21. with Stop PAN and try cycling the power on the WHIRC User s Manual Version 1 13 2013 October 18 58 DHE this should be a last resort and only after consultation with the Telescope Engineer A First Read echo mismatch message in the panSaver window may not be a serious problem Continue with the startup Continuing error messages in the panDaemon or panCapture windows after recycling the DHE power and verifying the fiber connection may require shutting down and rebooting the whirc pan computer itself If this does not help one may also need to reboot dust The OA should carry out this operation Problem The MOP does not complete the initialization process The MOP GUI is only partially complete and the WTTM client never opens Solution If the MOP is in a half complete state it may be waiting for a response from one of the other WIYN clients Check the MOP status and debug windows for error messages a message about an undefined variable or something similar may indicate that an old or incorrect version of the code has somehow been accessed In this case call for help from Dave Mills or Behzad Abaresh It is remotely possible that something could have been typed into one of the MOP fields rather than being selected from the pull down menu prior to the previous closing of the MOP and this was written into the initialization file Some of the windows are not always activated by a mouse over and entering a command into a w
22. with XTCS If the MOP was initiated prior to the XTCS one can take images but not communicate with the telescope It may be necessary to debias and depower the detector exit the MOP then restart the MOP power and bias the detector There may also be a problem with the XTCS Ask the OA to offset the telescope from the OA console check that the telescope moves and that the offsets are recorded on the telescope status display monitor Problem When executing a scripted dither sequence with the IAS guiding the telescope offsets properly but the guide probe does not follow Solution The XTCS may not know which guider to control Make sure that if one 1s using IAS guiding the WTTM EnableDisable button on the WTTM Client GUI Figure 5 10 has been pushed Also have the OA verify that the follow probes guiding option has been activated Problem When executing a scripted dither sequence with the IAS guiding the telescope does not move during one or a few of the offsets Solution If the commanded offset would move the IAS guide probe out of its physical range the probe may not move at all although it should maintain guiding The result may be a sequence with a discontinuity in the desired pattern usually at one of the extreme locations Before executing the script one must check with the OA that the guide star is sufficiently within the probe limits to permit all of the guided offsets in the script One may want to try a test of
23. 0 7 and 0 8 v have shown that the ratios of flatfield images taken at different integration times and corrected for nonlinearity section 3 3 are generally within 1 of the expected value Long term 4 5 years stability of flats in a given filter is generally better than 1 although somewhat degraded 2 in the palmprint area of the array Scans of a standard star over the field suggest that photometry to at least 2 rms is possible The sky background in the Ks and H filters 1s sufficient to permit one to generate sky flats from a series of target observations utilizing integration times long enough to yield background signals gt 5000 ADU or so It is necessary to obtain a series of dark frames taken at the same integration time to subtract out the bias and dark current Dome flats are taken with the telescope pointing at the internal dome screen which is illuminated by lamps on the telescope We recommend at least 10 flat images be taken through each filter used for observing these will be combined to reduce the statistical noise In addition we recommend taking an equal number of images with the lamp turned off to subtract from the lamp on flats The motivation is to eliminate dark current and any thermal background emitted from the warm surfaces in the optical train which are at varying distances from the instrument and most probably do not emit a uniform field of radiation We recommend taking lamp off data for all filters although d
24. 05 vhikeset 3 976 req 4 0 0 150 oct 26 13 22 26 whirc_bias check Bias_Tel 09 wiO0ut 2 465 req 2 5 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_ 10 wnUc 0 956 req 1 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 17 vpUc 3 464 req 3 5 0 150 oct 26 13 22 26 whirc_bias check Bias Tel 00 iIdle 2 270 req 2 21 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 02 vCas 2 991 req 3 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 06 vpD 3 956 req 4 0 0 150 Oct 26 13 22 26 whirc_bias check Bias Tel 07 vloReset 0 037 req 0 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 11 vdetCom 1 000 req 1 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_06 vloRowEn 0 960 req 1 0 0 150 oct 26 13 22 26 whirc_bias check Bias Tel 01 iSlew 3 118 req 3 12 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_16 vrstUc 0 976 req 1 0 0 150 Oct 26 13 22 27 whirc_bias Reset temperature monitor 7 a Click on the Update Voltages button screen should confirm that all the c6 29 voltages are OK The Voltages LED should be green and read ok ALBE x WHIRC Detector Biasing Temperature 0078 500 K Voltages ok J Power Detector 3 Bias Detector Reset Temp Monitor Update Voltages Oct 26 13 22 26 whirc_bias check Bias Tel _11 vdetCom 1 000 req 1 0 0 150 Oct 26 13 22 26 whirc_bias check Bias Te
25. 162 0917 12300 25 24 Bry 2 162 0 0215 0 849 7300 38 50 3 3 Linearity All infrared arrays utilizing a unit cell architecture are inherently nonlinear since the potential well created by the application of the bias voltage has a capacitance which increases as the collected charge fills up the well one may think of the two capacitor plates moving closer together In parallel with the capacitance of the rest of the unit cell this yields a gain which varies slowly as the well fills up Under the condition of constant signal flux the plot of signal vs time would begin at a slope near unity and slowly roll off until the array saturates Alternatively one can define a linearity function which is essentially the slope of the signal vs time plot normalized to the value at small signal levels We have carried out a quadratic fit to the linearity function for 0 7 v bias up to a value of 38000 ADU By inverting this function one can derive a linearity correction function so that the corrected signal S is related to the raw signal S by S S A B S C S where A 1 000 A 1 000 B 1 29x 107 0 004227 C 2 506 x 107 0 02691 The IRAF task irlincor is specifically designed to carry out this correction the coefficients A B and C above are the irlincor values Jt is critical that linearity correction be performed on the raw data prior to any sky or dark subtraction Data obtained usin
26. 300 s integration times o Narrowband Filters One will almost always operate in Fowler 4 mode to realize the advantage of lower read noise 17 e and use long integration times 300 s or more with IAS or WTTM guiding Integration times as long as 1000 s have been used successfully Depending on the OH airglow intensity one may be background limited in 600 s in all except the Low Airglow and He I filters e General Particularly for fainter science targets aren t they all there is an element of judgment involved in selecting the individual frame times The use of guiding will increase the overhead by a few seconds per observation but is well worth it if the seeing is good if one can use longer integration times as a result the guiding overhead is recovered by writing fewer images to disk If the sky is particularly variable more observations at shorter integration times may be preferable The additional overhead of using Fowler 4 vs Fowler 1 1s approximately 12 s per image for integration times gt 60 s use of Fowler 4 is probably warranted except in the H and Ks filters While longer frame times benefit the S N under very low background conditions removal of systematic and cosmetic effects benefits from a larger number of images Thus for a source requiring a total of 60 min of on source time six 10 min frames may be preferable to three 20 min frames 6 2 3 Guiding As noted above guiding with the IAS guider imposes small ove
27. 50 Oct 26 13 22 26 whirc bias check Bias Tel 08 vloRowEn 0 960 req 1 0 0 150 Oct 26 13 22 26 whirc_bias check Bias Tel 01 _iSlew 3 118 req 3 12 0 150 Oct 26 13 22 26 whirc_bias check Bias Tel 04 vhiRowEn 4 970 reg 5 0 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel_16 vrstUc 0 976 req 1 0 0 150 Oct 26 13 22 27 whirc_bias Reset temperature monitor NN Figure 5 11 The WHIRC Detector Biasing Window now automatically loaded with the MOP WHIRC User s Manual Version 1 13 2013 October 18 21 BA X SAOImage ds9 File Edit View Frame Bin Zoom Scale Color Region WCS Analysis Help File Object 7 Value WCS i Physical x Yol Image x Y Framel Zoom 1 000 Angle 0 000 fle edit view frame bin zoom scale color region wcs help about open save image save fits save mpey print page setup exit a coc eee 10 20 30 40 ou 60 70 aQ 30 a Figure 5 12 The SAOimage ds9 display window also automatically loaded 6 Single click on the PyRAF button to bring up a PyRAF shell window for analysis of the data 6868 Xx pyraf dust HOAD PL IFHF Revision 2 24 2 EXPORT Sun Jan 25 16 U39 L3 MST Ue This is the EXPORT version of PL IR F 42 12 supportinc most PL eystenz Welecme tc IRAF To list the available commands type Y or YY To get de
28. ABE 4825339 836 Number of frames 11 observer idatafdata 01_ Mar 12 propid 20124 0666 File name dark_100s cdo eo EEE E Automatic display J Overunte files observe name d lt rk_100s exposure 1 00 type Dark number 1 Filters LOW AIR HE H2 BR_G_4500 BR G FE_Il_ 4500 FE II CH PA B e Fowler 1 WHIRC 7 Fowler4 Readout ase Modes Min Exposure secs 3 5 Figure 5 19 WHIRC MOP with an exposure in progress WHIRC User s Manual Version 1 13 2013 October 18 30 3 An exposure countdown window will pop up and count down the seconds of the exposure time If multiple frames or repeats are selected the Frame number will index After the exposure time completes three messages will appear in sequence to note the processing steps of the data a the detector head electronics DHE will be read b the Fowler frames taken before will be subtracted from the Fowler frames taken after the exposure c the FITS file 1s created and stored on the disk countdown Pe F i countdown heon r kl countdown countdown Figure 5 20 Countdown screen during an exposure DHE read and disk writing WHIRC User s Manual Version 1 13 2013 October 18 31 4 The FITS file created is automatically displayed into ds9 if the Automatic display button is checked Typing imexam in the PyRAF window will put a cursor in the ds9 window which can be used to analyze the properties of t
29. As noted above WITM may typically produce FWHM improvements on the order of 0 1 0 15 arcsec but can be much more effective in reducing the effects of wind shake on the telescope l During the initial startup procedures the OA will boot up the WTTM computer load the software start the LVDT monitor for the x y stage and check APD operation Go through the normal WHIRC startup sequence described in section 5 The OA may ask you at some point to push the WTTM Enabled button and to ensure that the Guided Dithers button is not active When observing bright standards if guiding is not required the OA will have the WTTM guiding turned off To observe a science field with WITM go to the field and take an exposure ask the OA to move the telescope to center the field if necessary Identify the guide star in the image and use imexam to determine the x y pixel coordinates on the detector The OA will enter these coordinates to send the APD probe to the position of the guide star If all goes well the APD signal will be visible on the APD Count Monitor screen at the OA terminal Verify that the WTTM guide probe will be able to accommodate the telescope motions during the execution of the MOP script It may be necessary to find a guide star closer to the center of the science field Based on the signal level the OA will determine an appropriate sampling frequency and activate WTTM Download the appropriate MOP script and execute
30. Capture Window i a8 Thu 4 25 PM observar Q tant PAN Start MOP WHIRC Figure 5 1 The initial screen after logging into wiyn 2 as observer on the left hand of the two monitors Initially one will see only the column of icons on the right hand side Double clicking on the WHIRC icon magnified on lower right will bring up the WHIRC menu icon magnified on lower left which is used to bring up WHIRC The Autolog button is a recent addition which will bring up a log page which automatically stores image information in a PostScript file and allows the user to enter comments for each observation if desired WHIRC User s Manual Version 1 13 2013 October 18 13 3 Ask the observing assistant to single click on the WHIRC Engineering icon on the OA s screen to bring up the WHIRC Engineering GUI which shows status and provides control over the filter wheels and temperature control for WHIRC if it is not already up and running These windows are for use by the WIYN staff only not by general observers There are four tabs a Options a text status page on the filter and temperature control subsystems Fig 5 2 whire Fiter WIYN Staff use Only Temprrstira Canten Trmperatine 4802 sep 26 17 50 25 Sage 2 2h 17 AN sep 26 17 50 20 Debug Level ut LS34U lemperature Sup 26 17 50 gt gt Sep 26 17 50 30 tivhise 2 1u34U 7 Led fe so 28 17 50 30 Sup 26 1 5U 3U Sep 2
31. Fig 5 12 Note If the XTCS is not running on the OA s computer you will get a pop up stating that the XTCS cannot be contacted For the purpose of doing afternoon calibrations and dome flats the XTCS is not needed and you can click OK However the XTCS must be running in order for WHIRC to do on sky observations a MONSOON Observing Platform This panel is the Observer Interface for observing with WHIRC User inputs include the exposure time filter position detector readout mode object name and observer The RA and DEC are supplied by the WIYN TCS The File pull down menu is used for loading standard dither scripts or a custom observing script file The PAN pull down menu can reopen the PAN window 1f 1t 1s iconified Xx Monsoon Camera Control whirc File Comms Opts PAH Help target dark Exposure type Dark il ra 02 01 13 1653 Exposure in seconds 1 5 0 ee 02503316 Nurber of Frames 2 observer idatalata 01_Mar_12 poopie 20124 0666 Fila name 2 dark5s cdo P E Aut malc display Uwverumte Tiles observa name carkos exposure 3 0 tyee Dark number e0 Filters LOW_AIR HE H BR_G_4500 BRG FE_Il_4500 FE II CH PAB Fowler 1 WHIRC gt Fowle 4 Readout Modes Min Exposure secs 3 0 Figure 5 7 The Monsoon Observing Platform for WHIRC WHIRC User s Manual Version 1 13 2013 October 18 19 b MOP debug log This window displays the status of the MOP commands and is useful to help deb
32. H 17 50 32 gt Sep Z6 11 58 32 Nap 2R 17 50 38 Sep 2 17 50 38 Sep zb k ae sep 86 17 50 30 2R 17 50 41 mah h T AN A Sep 26 17 50 41 sep 26 17 50 41 Sry th WS SH AA Sep Zh 17 AN 44 Sep 26 17 50 45 sep 6 17 50 51 Sep 26 1 5U 51 Scop 2b 1 5U 53 sep 26 17 50 56 whircg deena vy whee nly wwhireg whire W confirm corneas W log autoscroll W error beep denr Status Rastart Darme otate IDLE op goal UYE SWE realtine node acquiring new log data TTE Lw 1000 WARNING sipping strange log record whired count gt Sle Liny mite gt uul vuap lule init completo init rn len inib samp llas gt uul vuaplulo Eegioter_gve vhire_ocrver comner tin7 tn temperature whirr ricm lar yasal whine gt Curl iyur iwy commanding 2 noop enumanding 43 ah act filtar statne I emmperting tn fel vhire connecting to tw whirc y Teeperatare control Liy Sind crap Lamp aln ie ulls bala lu IME Aa executing 2 e command executing fJ collect filter status 1 eee status ES ae sel y rmbareracom ermano 4 nal eg de iter_atatan H command executing 4 collect filter status 2 B collecting shan for filter vheel 2 inbi emda we EMMA a aa inet _teaperatire atata command executing 5 collect temperature status commanding 6 set sample period 2 0 gt vuan esevulany f6 sel aiet ea
33. Oct 26 13 29 42 whirc_bias Reset temperature monitor Oct 26 13 29 42 whirc_bias check Bias_Tel_05 _vhiReset 3 976 reg 4 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 09 wn0ut 2 497 req 2 5 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 10 wnUc 0 964 req 1 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 17 vpUc 3 484 req 3 5 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 00 _ildle 2 270 req 2 21 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 02 vCas 2 991 req 3 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 06 vpD 3 958 req 4 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 07 vloReset 0 037 req 0 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 11 vdetCom 0 992 req 1 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 08 vloRowEn 0 968 req 1 0 0 150 Oct 26 13 29 42 whire bias check Bias Tel 01 islew 3 118 req 3 12 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 29 42 whirc bias check Bias Tel 16 vrstUc 0 271 req 0 3 0 150 Figure 5 16 WHIRC Detector Bias window after successfully biasing the detector 8 Optional Single click on the WHOMP icon to bring up the WHIRC Observation Manager and Planner on the Observer monitor The observer can use this window to plan more complex mapping and dithering observations than the small menu of simple dithers and small map provided in the MOP An observing script
34. Size arcsec Y Dither Size arcsec a ad 20 20 A A ee Dither Repeat 1 Dither Repeat 1 Expose Repeat 1 Exposure time s Figure 5 29 The WHOMP GUI for a complex script consisting of a 3x3 map with 180 arcsec offsets with a 2x2 dither 30 arcsec offsets at each of the nine map positions The graphics display shows the relative locations of the 36 observations In addition a sky observation 2x2 with 20 arcsec offsets at a location 0 1 degree away in both RA and DEC is executed for each of the nine map positions WHIRC User s Manual Version 1 13 2013 October 18 4 5 7 Editing a WHOMP Script The WHOMP 1s a very versatile tool for setting up complex observing scripts which are customized to specific targets One of the strengths of this tool 1s the ability to generate observing scripts at one s home institution well in advance of the actual observing run and enter them into the observing scripts directory at the time of the run However for relatively simple observations this customized nature can be annoying For example the target name GLM GC in the example shown in Fig 5 27 which is written to the file GLM GC setup2 obs and the exposure time 20 s will overwrite any user input to the MOP once the observing script is loaded so 1f one wished to use the same geometric pattern for a different target and or at a different integration time one could not simply load the script and change the File name and integration times i
35. The optical system consists of a five element collimator and a five element camera A fixed cold stop is located at the pupil image formed by the collimator The two filter wheels are located on either side of this stop placing the filters very close to the pupil image in the collimated beam A single LN reservoir provides cooling for the optics and the HgCdTe detector whose temperature is regulated by a servo control loop The detector controller is the Monsoon system developed at NOAO Figures 3 1 and 3 2 show schematics of the instrument and a closeup of the optical assembly WHIRC User s Manual Version 1 13 2013 October 18 4 Vacuum Vessel WTTM Shim Radiation Shield G10 Support Tube Figure 3 1 Assembly drawing of WHIRC The shim is used to adjust the axial location of WHIRC so that the WI TM focal plane is imaged onto the detector G10 Support Tube Filter Wheels Optical Bench Radiation Shield Baffles Window Detector Field Stop Collimator Lyot Stop Camera Figure 3 2 Close up of Fig 3 1 showing the optical elements in more detail WHIRC User s Manual Version 1 13 2013 October 18 5 3 1 Filters The two 8 position filter wheels allow a total of 13 filters Each filter wheel must have one open position and one wheel has an opaque blocker for taking dark frames Table 3 1 lists the filter characteristics as well as the observed signal in ADU s corresponding to a mag 10 0 star determined from observa
36. WIYN High Resolution Infrared Camera WHIRC User s Guide Dick Joyce Margaret Meixner Todd Miller Edward Churchwell Version 1 13 2013 October 18 Vacuum Vessel WTTM Shim Radiation Shield G10 Support Tube WHIRC User s Manual Version 1 13 2013 October 18 1 1 0 INTRODUCTION Suri aia aaa 3 2 0 USEEUETACTS 62 oca Uta 3 3 0 INSTRUMENT DESCRIPTION oi A caes 4 3 1 A A A ee oe cee Re A ee cen ee 6 3 2 SIGNAL AND BACKGROUND LEVES 0 tod 6 3 3 RA 7 3 4 A II NT A NN 8 3 5 ELAINE 8 4 0 SYSTE MARCHE TECTURE a A 10 5 0 OBSERVING WITH WHIRC ccccccccscccccscccccccccccccccccccccccccccccccccccccccccccccccecccccccoccoccocces 12 5 1 STARTING UP WHIRC FROM SCRATCH 3 e ee ed ao 12 5 2 SHORT SUMMARY OF NORMAL WHIRC START UP SEQUENCE cccccsscccssscesccesccesceesceessenees 26 5 3 STEIN Ge DOWN VV TR We e O 27 TAKINGAN OBSERVATION USING THE MOB did 28 5 4 USING THE MOP WITH AN OBSERVING SCRIPT cccscoscescecceccecescesceccscescescectscescescescesescescseeses 34 5 5 OTHER MOP TUN CTON Sd de a Oo 38 5 6 MAKING AN OBSERVATION SCRIPT USING THE WHOMP 0 cecceccececcecceccecescesceccscescesceses 38 5 7 EDITING A WHO MES CRIT e a ea la e Dd 42 6 0 OBSERVING STRATE GIRS cunas 45 6 1 TR STRATEGY IN GENERAL a e tele ao dee toto de il na do 45 6 2 WETRESTRATECIES a de ode tai a ET A 46 7 0 WEEP OPERATION 6 aa 52 7 1 MITEM DESCRIPTION e esta eee 52 7 2 ESIN AET A a A OR 54 8 0 TROUBLE SHOO TIEN G
37. addition because the APD error sensor light passes through the WI TM active optics the field is only slightly larger than that of WI TM approximately 4 arcmin Fig 7 4 This is still significantly smaller than the available range of the IAS guider Fig 6 1 WTTM guide star acquisition uses the coordinates of a suitable star in the WHIRC field so large dither patterns should not be attempted using WI TM guiding A WTTM guide star close to the center of the field increases the allowable probe motion We strongly suggest that observers locate potential guide stars for their fields prior to arriving at the telescope This is particularly important in determining if there are no suitable guide stars available for WTTM since this lets one know in advance that the IAS guider will be necessary for observing that field Jenny Power has written a tool which searches for WI TM guide stars for a given coordinate and provides a list and graphical display of the WHIRC field with the guide star s identified The tool may be accessed at http www kpno kpno noao edu cgi bin kpno misc wiyn WTTMtool pl Once the science field is acquired and properly centered on the WHIRC field of view the observer should pick out a suitably bright star in the image and measure the x y coordinates on the ds9 using imexam The OA can then enter those coordinates into the WTTM control which should move the error sensor probe to the proper coordinates to pick up the star Once th
38. ages procedure WHIRC User s Manual Version 1 13 2013 October 18 23 b Click on the Power Detector button which should go with no errors and turn green bringing up a confirmation window Click OK The readings of vdetCom and vrstUC should read the same value indicating the detector bias voltage is zero ADO Temperature 0078 500 K Voltages ok E Power Detector W Bias Detector Reset Temp Monitor Update Voltages Det 26 139 whirc_bias check Bias Tel x WHIRC Detector Biasing AD X Oct 26 13 26 47 whirc bias check Bias Tel Power detectar Oct 26 13 26 47 whirc_bias check Bias_Tel_ loct 26 13 26 47 whirc bias check Bias Tel_ j Oct 26 13 26 47 whirc_bias check Bias_Tel_ _ Oct 26 13 26 48 whirc_bias Powering VIRGO OK Cancel Oct 26 13 26 48 whirc_bias check Bias Tel_ Oct 26 13 26 48 whirc_bias check Bias_Tel_ pus 4 Oct 26 13 26 48 whirc_bias check Bias Tel 10 vnUc 0 956 req 1 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel_ 17 vpUc 3 464 req 3 5 0 150 Oct 26 13 26 48 whirc bias check Bias Tel 00 iIdle 2 270 req 2 21 0 150 loct 26 13 26 48 whirc_bias check Bias_Tel 02_vCas 2 991 req 3 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel_06_vpD 3 958 req 4 0 0 150 Oct 26 13 26 48 whirc_bias check Bias_Tel 07_vloReset 0 037 req 0 0 0 150 Oct 26 13 26 48 whirc_bias check Bias Tel 11 vdetCom 0 992 req 1
39. anager amp Planner WHOMP which is used to generate observing scripts Both will be described in later sections m F F e E T t a 7 i Y L r n r y r ji a 7 a T tre z pli ra gt Figure 4 1 Overview of the WHIRC system architecture WHIRC Observation Control System WHOCS Figure 4 2 Overview of the WHIRC system architecture showing the interaction of the MOP and WHOMP within the WHOCS WHIRC User s Manual Version 1 13 2013 October 18 1 5 0 Observing with WHIRC 5 1 Starting Up WHIRC from Scratch WHIRC is normally operated from the observer s station on the N side of the WIYN control room adjacent to the OA station The host computer is dust The observer s console is a Mac Mini computer named wiyn 2 which is a platform for operating most of the WIYN instrumentation without the need to physically change monitor keyboard and mouse hardware connections to the appropriate computer The Mac Mini has two 24 inch monitors a stereo speaker bar webcam mouse and keyboard Each monitor has two USB ports on the left side to attach external disks or other USB devices Wiyn 2 has four desktops if one moves the mouse to the top right corner of the right hand monitor or the lower left corner of the left hand monitor you will get a view of all four desktops and can pick one for use This can sometimes happen inadvertently and can be either convenient or annoying One should also be ab
40. arks of the same integration time are probably sufficient for the J and H narrowband filters WHIRC User s Manual Version 1 13 2013 October 18 S In Table 3 2 we list the recommended settings for dome flats through the WHIRC filters These assume an integration time of 5 s in Fowler 1 mode and 16 s in Fowler 4 mode partly to keep the process of generating flatfields from being too time consuming but also to minimize dark current and the thermal background flux mentioned above The target signal level is approximately 10000 ADU in Fowler 1 and the equivalent 40000 ADU in Fowler 4 Comparison of flats taken in Fowler 4 and Fowler 1 modes show them to be almost identical but we recommend a conservative approach and suggest obtaining flats for Fowler 4 science observations in Fowler 4 mode as well Table 3 2 Recommended Lamp Intensities for WHIRC Flats Fowler 1 5 s Fowler 4 16s HIGH LAMP SETTING Jo 000 47044300 Lowairglow 1650 11000 1120 44500 He1 190 10600 1940 44600 PCN 1450 11000 1000 44600 Pap 450 3 5 1 Pupil Ghosting 1000 470 340 820 680 640 570 300 The WHIRC flat images display a pupil ghost which is an artifact seen in many refractive imagers Unlike image ghosts which arise from multiple reflections of the light from a bright source and manifest themselves as distorted and defocused images of the target which move as the target does the pupil ghost is a fixed feature
41. at tip tilt correction represents the first step towards adaptive optics but it is only a first step Tip tilt correction will not miraculously produce excellent images when the seeing 1s poor although experience in the optical showed that with seeing gt 1 0 arcsec WTTM could significantly reduce the image motion The best results observed in the visible were when the native seeing was in the 0 5 0 8 arcsec range with improvement of 0 15 to 0 18 arcsec in FWHM When the seeing was excellent lt 0 45 arcsec the degree of improvement was mixed Our experience with WHIRC Fig 7 2 is qualitatively similar We anticipate that the improvement in native seeing at longer wavelengths combined with the larger diffraction disk may result in corrected images which approach the diffraction limit in the K band Because WHIRC is mounted on the WTTM port the light is always passing through the WTTM optics even if active correction is not being used The six additional reflections four WTTM surfaces the pickoff mirror and dichroic will affect the system throughput and more importantly increase the thermal background seen in the K band The expectation is that the improved image quality seen in the K band with active tip tilt correction will compensate for the higher background surface brightness While observers may wish to familiarize themselves with the operation of WTTM the actual setup and operation of the system is carried out by the OA A
42. can be created in the WHOMP GUI stored and uploaded by the user into the MOP for execution The target name is used for both the header information and as the rootname for the FITS file of the observation The coordinates of the target can be input for previewing with a DSS overlay but they are ignored by the MOP and the FITS header takes the telescope systems coordinates for the header 0005 X WHIRC Map Designer File Recipes View Help WHOMP Version 1 82 20 Oct 2010 Target Name none Target Coordinates Heliocentric Equatorial Coordinates fe wN 4 Equatorial Right Ascension OH po M 0 000 S fee ecliptic Declination oD o 0000 wv Galactic Ro 0oDf o f 0000 Equinox 2000 Map Designer Number of X Cells Number of Y Cells Shape Selector 1 1 Grid LS LS Plus X Cell Spacing arcsec Y Cell Spacing arcsec a 200 200 E EE Ee Map Repeat 1 Sky Dither Designer Map Dither Designer X Offset deg 1 Y Offset deg 1 Number of X Dithers Number of Y Dithers Shape Selector Number of X Dithers Mumber of Y Dithers Shape Selector 1 1 Grid 1 1 Grid Ef g h J j us Plus X Dither Size arcsec Y Dither Size arcsec ES x X Dither Size arcsec Y Dither Size arcsec a 20 20 y 20 20 gt A E A Dither Repeat 1 Exposure time s 1 Dither Repeat 0 Expose Repeat 1 Exposure time s 1 p Figure 5 17 The WHIRC Observation Manager and Planning WHOMP GUI WHIRC User s Manual Version 1 13
43. d processes including logging This will also clear the link If the window had been minimized during observing bring it up by clicking on the monsoon whirc pan icon on the wiyn 2 taskbar NOTE Additional step if shutting down the whole system 5 Close the WHIRC Engineering GUI by clicking on the Quit button in the lower left corner of the screen NOTE Additional step if WHIRC needs to be powered down e g electrical storm or transport to town for maintenance 6 Turn off the DHE power and other WHIRC power by walking to level B of the telescope skirt and switching the power strip to the off position you will need a step ladder to reach the switch This will turn the power off to the DHE the LakeShore temperature sensors detector heater and gaussmeter sensors WHIRC User s Manual Version 1 13 2013 October 18 27 Taking an Observation Using the MOP 1 In the MOP window set up an observation a Change to the desired filter by clicking on the appropriate filter button This action will move both filter wheels to the desired location for the filter One of the filter wheels will be in an open position and the second will be moved to the position of the filter x Monsoon Camera Control whirc File Comms Opts PAH Help target dark Exposure type Dark ra 02 47 04 2393 Exposure in seconds 100 iet 4825339 796 Nurber of frames 3 d observer Charfrfan idatafdatadl Mar 12 propid 20124 0666 F
44. ddressed by taking multiple exposures of the field with small telescope motions in between This technique usually referred to as nodding or dithering is a standard infrared observing technique In a relatively sparse field the sky level for each object is measured by the other observations since the sources will be at different locations on the detector By the same token the effect of dead or noisy pixels at specific locations on the detector can be eliminated by moving the source onto different pixels for each integration In theory this technique can work with as few as two positions Subtracting one image from the other effectively removes the background signal as well as bias and dark current leaving positive and negative images displaced from each other However having only two measurements makes it difficult to evaluate the presence of bad or noisy pixels and the subtraction process increases the noise by V2 We generally recommend a minimum of 4 or 5 dither positions since this gives better sampling of the target image on good pixels Furthermore in sparse fields one can combine the images with a median sampling algorithm to obtain an image from which the sources are removed This sky image can then be subtracted from the original raw images to generate sky subtracted images Because the sky image is an average of several raw images the noise penalty is reduced as well For very deep observations the dither
45. e star is located the OA can turn on the WTTM guiding and science observations can begin As noted above the WTTM probe will follow telescope motions commanded by an observing script as long as it 1s not requested to move outside its limits of motion WHIRC User s Manual Version 1 13 2013 October 18 54 APD Response R Magnitude vs APD Counts ontaminated Optics A variable seeing February 2009 Contaminated Optics 0 8 seeing January 2008 Clean Optics May 2008 Clean Optics January 2009 C 1 Faint Limit at 100Hz Sampling i 40cnts per sample interval above sky R Magnitude 100 1000 10000 le 05 APD Counts cnts sec Figure 7 3 R band magnitude plotted against APD error sensor count rate obtained on several WT TM commissioning nights Courtesy C Corson and H Schweiker g WHIRC WTTM na Guider a Figure 7 4 Schematic of the WT TM guide field with respect to the WHIRC field of view The initial guide star position must lie within the WHIRC field since its coordinates are use to move the WTTM probe to the star location WHIRC User s Manual Version 1 13 2013 October 18 55 7 2 2 WTTM Control The details of WTTM operation are handled by the OA but there are several functions which must be done by the observer using the WTTM Client GUI which appears automatically when the MOP is started up Fig 5 10 Fig 7 5 The WTTM probe controller has been referenced to the WHIRC field so the
46. ector pixels to the desired bias voltage of 0 7 v The entire array 1s then read out nondestructively followed by a second nondestructive readout The time interval between the initiation of the first read and the initiation of the second read is by definition the integration time The first readout is then subtracted from the second to provide the single bias subtracted image which 1s stored on disk This mode of operation which is also referred to as Fowler 1 1s used for most observations with WHIRC particularly those where photon noise from either the source brightness or sky background is significantly greater than the detector read noise For observations of faint targets in the narrowband filters one may use the Fowler 4 mode in which the array is read out four times each at the beginning and end of the observation This can reduce the read noise up to a factor of two The minimum possible integration time is by definition the time to read out the array which is 3 77 s For the Fowler 4 mode with four readouts the minimum integration time is increased to 15 2 s For long integrations on faint targets this additional overhead is small and 1s well worth the advantage from the lower read noise 3 0 Instrument Description WHIRC 1s a straight through all refractive imager with no moving parts except for the two filter wheels This design was dictated in part by the stringent instrument envelope and weight requirements of the WI TM port
47. es to minimize the overhead If doing broadband and one or two narrowband filters it may be more efficient to use longer 60 s integration times for the narrowband filters so one can observe a single standard in all filters If one is observing through a large number of narrowband filters 1t may be more efficient to find a brighter standard for those observations WHIRC User s Manual Version 1 13 2013 October 18 47 e Faint targets o Broadband Filters J H Ks One will generally want to pick an exposure time sufficiently long to achieve background limited performance in a single exposure For Fowler 1 mode readnoise 28 e this means achieving a background level gt 600 ADU 2400 e This is quite easy in the Ks band and depending on the season one will probably want to pick an integration time which gives a background 10000 15000 ADU In the H band background saturation is not an issue and the integration time is a tradeoff between duty cycle and image quality and whether one is guiding or not Observers have used integration times of 100 s without noticeable image degradation under good 0 7 arcsec seeing conditions without guiding For deep observations in the J band one may wish to use Fowler 4 mode since the lower read noise gives a lower threshold gt 200 ADU for background limited operation One can then use integration times 75 100 s and achieve background limited operation with guiding observers have used
48. etScope command may use the modes set or adjust The set mode will execute a telescope offset to the coordinates X and Y arcsec in RA and DEC respectively with respect to the original telescope pointing In other words these are absolute offsets and any manual offset earlier performed by the WHIRC User s Manual Version 1 13 2013 October 18 42 OA 1s disregarded The adjust mode will execute a telescope offset by X and Y relative to the current telescope position 2 As an example to execute a four position dither in a square 30 arcsec on a side with respect to the original telescope pointing one could use the sequences offsetScope set 15 0 15 0 offsetScope set 15 0 15 0 offsetScope set 15 0 15 0 offsetScope set 15 0 15 0 each followed by an observe sequence At the end the command offsetScope set 0 0 0 0 will move the telescope back to the initial position 3 If one wishes to execute the same dither script with respect to the current telescope position one would use the following sequence offsetScope adjust 15 0 15 0 offsetScope adjust 30 0 0 0 offsetScope adjust 30 0 30 0 offsetScope adjust 30 0 0 0 each followed by the observe sequence At the end the command offsetScope adjust 15 0 15 0 will move the telescope back to the initial position NOTE This is now the default syntax created by the WHOMP 5 7 2 WHOMP Observing Syntax As noted above an observing script created
49. ew frame bin zoom scale color region WES help center align in out to fit none E y xy O degrees 490 degrees 160 degrees 70 degrees E 04 3E 04 4F 04 Figure 5 22 ds9 display of an image of the Trapezium in M42 WHIRC User s Manual Version 1 13 2013 October 18 33 5 4 Using the MOP with an Observing Script 1 For a more automated approach to dithering and mapping one may use a canned script or load a custom script made with the WHOMP To load the script use the pull down menu from the File button d b The std_x5_50arcsec obs does a 5 point X pattern on the array with 50 arcsec separation between the corner points The std_3x3_50arcsec obs does a 3x3 box pattern on the array with 50 arcsec separation between the points The std_ 5 50arcsec obs does a 5 point cross pattern on the array with 50 arcsec separation between the corner points The std_5x5_100arcsec obs does a 5x5 box pattern on the array with 100 arcsec separation between the points To load a custom made script e g by the WHOMP select Load observing script from the File pull down menu and search the directory area for your script file The home observer observing scripts subdirectory contains the canned and custom observing scripts To unload any script 1 e to get out of script observing mode select Unload current script from the File pull down menu NOTE All of the canned standard scripts have a rotat
50. fset using the guide star prior to executing the script Problem When executing a scripted dither sequence with WTTM guiding is lost Solution The XTCS may not know which guider to control Make sure that if one is using IAS guiding the WTTM Enabled button on the WTTM Client GUI Figure 5 10 is WHIRC User s Manual Version 1 13 2013 October 18 63 not active If the telescope offsets properly have the OA check that the WTTM probe is also moving If both the telescope and WTTM probe are moving properly it is possible that the guide star 1s too faint or there is a hardware problem with the APD quad sensor itself Problem When executing a scripted dither sequence with WTTM the probe follows the offsets properly but moves at a very slow rate Solution This occurs if the Guided Dithers button on the WTTM Client GUI is active The WTTM guiding does not turn off during offsets but moves the probes slowly 1 25 arcsec sec dragging the telescope along Problem After executing a scripted dither sequence properly the Run Script button changes to Observe and the script may automatically unload Solution For totally unknown reasons this can occur if the last command in the script is an Observe command The script should terminate with an offsetScope command WHIRC User s Manual Version 1 13 2013 October 18 64
51. g Fowler 4 mode must be divided by 4 prior to linearity correction WHIRC User s Manual Version 1 13 2013 October 18 7 3 4 Saturation Because of the fine pixel scale of WHIRC it is tempting to think that saturation on brighter stars 1s not as critical as for a wide field imager with larger pixels but the combination of a 3 5 m aperture a 4 s minimum integration time and good image quality does mean that one must consider this issue Under good seeing conditions at WIYN and with active WITM correction WHIRC can achieve image cores with FWHM lt 3 pixels similar to what one obtains with FLAMINGOS on the 4 m under median seeing conditions The data presented in Table 3 1 were obtained under seeing conditions 0 5 arcsec 5 pixels FWHM Empirically the peak pixel flux was typically 0 03 of the integrated flux within the 1 6 arcsec diameter aperture For a H 10 0 star in the minimum integration time of 4 s this yields a peak pixel signal of 23000 ADU seemingly at a safe level of slightly over half full well However seeing fluctuations over these short times could result in good images which push the peak pixel close to saturation Finally note that we have settled on a bias value of 0 7 v over the value of 0 8 v also tested during commissioning since the lower bias appears to give fewer maverick pixels However the saturation level is reduced to 35000 ADU 3 5 Flatfielding Linearity tests with bias values of
52. han stopping the observing sequence and running through the focus optimization It is worth noting that the thermal temperature gradient within the primary mirror from the front plate to back web dominates over other focus variations and is very difficult to predict Once the entire glass has settled to near ambient temperatures focus variations will stabilize WIYN currently utilizes only the temperature difference between glass and ambient air for focus correction although the primary mirror has been instrumented with an array of temperature sensors to eventually incorporate gradients into the focus correction lookup table The telescope focus will also change with elevation angle the WIYN telescope control system will compensate for this using a lookup table but it is still a good idea to check the focus when moving a significant distance to a new science field Naturally one is more sensitive to focus changes when the image quality is good so one should be prepared to update the focus more frequently under these conditions WHIRC User s Manual Version 1 13 2013 October 18 51 7 0 WTTM Operation WHIRC is mounted on the WI TM WIYN Tip Tilt Module port of the telescope Instrument Adapter System We anticipate that the tip tilt compensation from WT TM in combination with the excellent native seeing at WIYN can result in near diffraction limited images 0 2 0 25 arcsec in the K band NOTE The commissioning of WITM for use
53. he stars such as full width half maximum FWHM when doing a focus check Two examples of a ds9 window are shown below Figure 5 21 is an almost blank field of uniform sky emission that shows the detector artifacts well The black columns on the right are the detector reference pixels The faint vertical black columns are the first columns of the section of the detector read out by a particular amplifier The speckling of black and white dots are low sensitivity regions and hot pixels The white horizontal lines are hot rows 0005 IX SAOImage ds9 File Edit View Frame Bin Zoom Scale Color Region WCS Analysis Help File dark 5s 012 fits ark Object Value WCS Physical Image fl edit T view frame n zoom scale color region s help about open save image save fits save mpeg header print page setup exit U ll 40 BU ol 100 A Figure 5 21 ds9 display of nearly blank field showing detector artifacts The lighter columns on the right are reference pixels and are not part of the image WHIRC User s Manual Version 1 13 2013 October 18 32 The image in Fig 5 22 is of the Trapezium in the Orion Nebula While the trapezium stars themselves are saturated many fainter stars and the HII region nebulosity show brightly 5A0lmage ds9 File Edit View Frame Ein Zoom Scale Color Region WCS Analysis File orion 0 186 fits Object Orion Trapezium Value WCS Physical Image file edit vi
54. ig 5 28 and can then be loaded into MOP with the Load Observing script function in the File pull down menu NOTE currently the RA and Dec loaded into the WHOMP are not used by the MOP in the scripts just for viewing a pattern on the ds9 As noted above the Roll parameter is used to rotate the field on the sky from the nominal orientation although the sense of this is reversed from normal Figure 5 29 demonstrates a complex script which includes both mapping and sky observations The basic pattern is a 3x3 map with 180 arcsec offsets allowing about 10 overlap of adjacent fields each point of which has a 2x2 dither pattern with offsets of 30 arcsec The 36 observations are shown on the GUI using the View pull down menu In addition sky observations 2x2 grid with offsets of 20 arcsec are done at a point 0 1 degree away in both RA and DEC from the initial observation point The sky observations are performed after each of the nine map locations for a total of 72 observations ADA Xx WHIRC Map Designer Help File Recipes View WHOMP Version 1 82 20 Oct 2010 Target Name IGLM GC Target Coordinates Heliocentric Equatorial Coordinates Equatorial Right Ascension 0H OM 0 0008 w Ecliptic Declination po D po 0 000 eh baat A es AN MeF Mt t w Galactic Roll DD Qs 0 000 Equinox 2000 Map Designer Number of X Cells Number of Y Cells Shape Selector 1 1 Grid Plus X Cell Spac
55. ile name dark_100s ca AA E Automatic display J Overnvnite files observe name dark_100s expesure 1 00 typs Dark number 4 Filters LOW AIR HE H2 HR G 4500 BRG FE I 4500 FE II CH PA B Fowler 1 WHIRC gt Fowler4 Readout awe Modes Min Exposure secs 3 0 Figure 5 18 WHIRC MOP for illustration of an exposure setup in this case a series of four 100s dark frames WHIRC User s Manual Version 1 13 2013 October 18 28 b Select the detector readout mode by clicking either the Fowler 1 or Fowler 4 radio button The use of rolling reset and Digital Average 4 are now the default modes for observing so they are not explicitly noted on the MOP 1 Fowler 1 uses a single readout at the beginning and end of the integration This mode will be used for broadband imaging and bright targets where one 1s either background or source photon noise limited and saturation 1s a concern 11 Fowler 4 uses four readouts at the beginning and end of the integration This will reduce the read noise by approximately a factor of two at the cost of a fourfold increase in the minimum integration time This mode is useful for faint objects or narrowband filters where one may be read noise limited even with long integration times NOTE The counts in the image files from the Fowler 4 will need to be divided by 4 to normalize the signal levels before linearity correction c Select Exposure type dark flat object etc from the pull down menu
56. in Figs 4 1 and 4 2 The Observation Control System WHOCS has three primary functions Interaction with the WIYN telescope o Telescope Control System TCS controls the telescope pointing etc o Instrument Adapter System IAS controls telescope guiding o Telescope focus control o WIYN Tip Tilt Module WTTM on which WHIRC is installed provides fast tip tilt correction using a reference star within the science field to improve the image quality WHIRC instrument control o Control of the two filter wheel motors o Detector temperature control o Housekeeping functions detector temperature filter status WHIRC detector control The WHIRC detector 1s controlled by the NOAO Monsoon data acquisition system which has two primary components o Detector Head Electronics DHE These run the detector precision reference voltages clock and bias etc The DHE 1s installed close to the WHIRC dewar itself connected by short cables o Pixel Acquisition Node PAN This is a linux computer whirc pan which connects to the DHE and effectively runs the array and acquires the data The observer will open the connection to the PAN during startup and close during shutdown WHIRC User s Manual Version 1 13 2013 October 18 10 Figure 4 2 shows the two WHOCS subsystems of particular interest to the observer the Monsoon Observation Platform MOP which is the user interface from which the observer controls WHIRC and the WHIRC Observation M
57. indow may inadvertently enter it into the previously used window If there are no error messages in the MOP status debug windows or the panDaemon window but the panDaemon window is in the middle of listing information there may be a communications hangup If the OA is around ask to reinitialize the telescope computer Problem The MOP GUI comes up correctly but the filter buttons never turn green Alternatively the filter buttons may indicate the correct filter but attempting to change the filters produces no activity Solution Check that the Engineering GUI at the OA station is up and running Have the OA check the filter status from the Engineering GUI If the filter wheels have problems or errors have the OA do the following on the Engineering Filters screen ensuring that each command completes before executing the next one Click Reset Gaussmeter Click Reset Wheel 1 Click Home Wheel 1 Click Reset Wheel 2 Click Home Wheel 2 ono oe WHIRC User s Manual Version 1 13 2013 October 18 59 Wait until both wheels indicate HOME on the Engineering GUI before attempting any motion through the MOP Problem The MOP GUI comes up correctly but a popup window indicating a problem with connecting to XTCS appears Solution If XTCS is not up and running prior to starting the MOP it will not establish communication with the telescope If one is doing afternoon dome flats where telescope control is not needed click the OK butto
58. ing arcsec Y Cell Spacing arcsec a 180 180 A EIEI Map Repeat 1 Sky Dither Designer Map Dither Designer X Offset deg a Y Offset deg Fo Number of X Dithers Number of Y Dithers Shape Selector Number of X Dithers Number of Y Dithers Shape Selector 2 2 A 2 2 Grid Grid j Plus sl pales Plus X Dither Size arcsec Y Dither Size arcsec bd X Dither Size arcsec Y Dither Size arcsec wy X a 30 30 20 20 _ ME _ WE _ e Ms Dither Repeat 1 Expose Repeat 1 Exposure time s 20 Dither Repeat 1 Expose Repeat 1 Exposure time s 20 pF Figure 5 27 The WHOMP GUI setup for a 2x2 dither script on a target and on a sky position 0 1 degree away in RA and DEC The Dither Repeat parameter has been set to 1 WHIRC User s Manual Version 1 13 2013 October 18 40 OA X WHIRC Map Designer File Recipes View Help WHOMP Version 1 82 20 Oct 2010 Target Name GLM GC Target Coordinates Heliocentric Equatorial Coordinates Ww y Equatorial Right Ascension e Nan IX Save As y Ecliptic Declination gt Directo Mome observer observing scripts v Galactic Roll je Hi Equ El 3x3grid_10s_30arcsec obs DP El 3x3grid_2Darcsec obs op ig El 3x3grid_3Darcsec obs Number of X Cells El 3x3grid_30arcsecdither obs Shape Selector 1 El 3x3grid_40s_30arcsec obs 4 Grid ms El 3x3grid_50s_30arcsec obs Plus El 3x3grid_100s_30arcsec obs v X Cell Spacing arcsec a mm Arf File
59. irst time or checking The setup below will observe the standard star a Nuti in the H band filter in a 5 point cross dither pattern with 50 arcsec separations A Monsoon Camera Control Script loaded File Comms Opts PAH Help Exposure type t Object gt target Alpha Muti ra 02 e0 oal Exposure in seconds so LE det ETETETT Nurber of frames 11 Wena aman idatafdatadll Mar 12 poon 20124 0666 File name nighti 24H Run Sep SL ILL E Automatic display _j Overnvnite files observe name night exposure 30 type Objact number 1 Observing script mhome fobseryerfobserving scHApis std_ 5 50arcsec obs Executing Loaded click Run Script to start OPAQUE LOW AIR H2 HR G 4500 i BR G FE II 4500 Fowler 1 WHIRC gt Fowler4 Readout bl Modes Min Exposure secs 3 5 FE II CH PA B Figure 5 24 The MOP after loading an observing script WHIRC User s Manual Version 1 13 2013 October 18 36 3 Once the script 1s running Run Script will turn into working during an exposure To stop a script from running click on Pause Script and Abort in that order if all goes well the current integration will complete and the script will halt at that point If you pause a script you can resume it by clicking on the Resume Script button which will appear once the script is paused To get completely out of the script and back to single observation mode or a different script open the pull down menu
60. is to automatically display the image k The MOP default 1s to NOT overwrite files unless Exposure Type 1s set to junk If an exposure creates a file which duplicates a name in the data directory the MOP will query for permission to overwrite the file One may also set the Overwrite files button to force overwriting but this is not advisable so use this option with extreme caution The Overwrite files option overwrites in place i e selecting 10 frames will yield only a single file although the separate images will be displayed as they are completed and it will do this silently without verification WHIRC User s Manual Version 1 13 2013 October 18 29 2 Click the Observe button to start the observation The MOP will change its appearance so that the Observe button turns green and says working Adjacent to this button an Abort button appears You can click on the Abort button 1f you wish to stop or cancel your observations This will bring up a window asking to confirm the abort operation One should use caution with the Abort procedure since is it not always reliable It may not halt the current exposure but should halt a script after the current exposure finishes The Abort button is greyed out during the detector readout since an exposure cannot be aborted at that stage Xx Monsoon Camera Control whirc File Comms Opts PAH Help target dark Exposure type Dark h ra 02 40 36 234 Exposure im seconds 100
61. l 08 vloRowEn 0 960 req 1 0 0 150 Oct 26 13 22 26 whire bias check Bias Tel 01 iSlew 3 118 req 3 12 0 150 Oct 26 13 22 26 whirc_bias check Bias_Tel 04 vhiRowEn 4 970 req 5 0 0 150 oct 26 13 22 26 whirc_bias check Bias Tel 16 vrstUc 0 976 req 1 0 0 150 Oct 26 13 22 27 whirc_bias Reset temperature monitor Oct 26 13 24 25 whirc_bias check Bias_Tel_05 vhiReset 3 976 req 4 0 0 150 oct 26 13 24 25 whirc_bias check Bias_Tel_09 un0ut 2 465 req 2 5 0 150 Oct 26 13 24 25 whirc_bias check Bias Tel 10 vnUc 0 956 req 1 0 0 150 Oct 26 13 24 25 whirc_bias check Bias_Tel_17 vpUc 3 484 req 3 5 0 150 oct 26 13 24 25 whirc_bias check Bias Tel 00 iIdle 2 270 req 2 21 0 150 Oct 26 13 24 25 whirc_bias check Bias Tel 02 vC6as 2 991 req 3 0 0 150 Oct 26 13 24 25 whirc_bias check Bias_Tel_06 vpD 3 958 req 4 0 0 150 Oct 26 13 24 25 whirc_bias check Bias Tel 07 vloReset 0 037 req 0 0 0 150 Oct 26 13 24 25 whirc bias check Blas Tel 11 vdetCom 0 992 req 1 0 0 150 Oct 26 13 24 25 whirc_bias check Bias_Tel_ 08 vloRowEn 0 960 req 1 0 0 150 oct 26 13 24 25 whirc_bias check Bias Tel 01 iSlew 3 118 req 3 12 0 150 Oct 26 13 24 25 whirc bias check Bias Tel 04 vhiRowEn 4 970 req 5 0 0 150 Oct 26 13 24 25 whirc_bias check Bias Tel 16 vrstUc 0 976 req 1 0 0 150 Figure 5 14 WHIRC Detector Bias window prior to top panel and after bottom panel carrying out the Updating Volt
62. le script 1s not recommended for a number of reasons particularly if using guiding e As noted above a very large map may result in driving the guide probe into a travel limit unless one has carefully set things up prior to the observation Jf the guide probe is commanded to exceed a limit it will not move and the next observation in the script will occur at the same location At best this will result in a displacement of the remainder of the script observations At worst the guide star is likely to be lost particularly when using WITM e A problem occurring in the middle of an extended script may make it more difficult to continue from that point e Unless conditions are very stable the focus will likely drift during the course of the observation WTTM may eventually incorporate autofocusing Observations of extended or crowded fields will generally not be able to accommodate a large guided offset to a sky field again because of the physical limitation of the guide probe motion Relatively small 10 15 arcmin offsets may be possible with the IAS probe depending on the direction and location of the guide star Fig 6 1 We are investigating having the guider turn off during scripted offsets to sky fields then resume once the telescope returns to the science field but this may prove difficult because the telescope tracking will drift during the unguided sky observations and the guider may not reacquire the guide star upon returning
63. le to operate WHIRC from the other Mac Mini computer wiyn 5 if desired although that is normally used for pODI operations The setup procedure requires interaction between the observer and the Observing Associate OA although it has been greatly simplified by incorporating the power and bias of the detector onto the observer s terminal Execute the setup commands in the order specified below You can rearrange the windows onto either of the two monitors as they come up For completeness the windows which display on the OA terminal will be described even though they are reserved for use by WIYN personnel only 1 Log into the computer wiyn 2 with the username observer and the password posted on the terminal This will bring up the default screen on the left monitor Figure 5 1 On the right hand side of the monitor one will see a column of icons including one for WHIRC Double click on this icon to open the session on dust and bring up the WHIRC start menu 2 At the start of each night the observer should execute a Stop PAN using the button at the bottom of the menu toolbar This will clear out any extraneous background processes which might be left over from the previous night as well as the link to the PAN computer While this should have been done at the end of the previous night when the session was shut down repeating the command is a conservative approach WHIRC User s Manual Version 1 13 2013 October 18 12 A Grab File Edn
64. lows WHIRC to achieve a broad range of scientific goals in stellar physics star forming regions and the ISM in galactic and extragalactic sources This document is a general purpose User Manual for WHIRC observers containing some general information on the instrument instructions for starting up the instrument from the WIYN observer s station and taking observations Starting up the instrument involves interaction between the observer and the Observing Associate OA so all steps will be described even though some of them are executed by the OA and not by the observer Some of the engineering level observing screens which appear only at the OA station will also be described since they appear as part of the normal startup but they are not for use by the observers 2 0 Useful Facts The table below summarizes some facts about WHIRC During the commissioning of WHIRC we experimented with several values for the detector bias and settled on a value of 0 7 v This has demonstrated good linearity behavior and is currently a good compromise between the number of isolated noisy pixels and the detector well capacity Measurements of the gain yield values near 3 3 3 4 we use the latter value Table 2 1 WHIRC Information WHIRC User s Manual Version 1 13 2013 October 18 3 The infrared array in WHIRC is operated in a non destructive double correlated sampling mode also referred to as reset read read The cycle involves biasing the det
65. mperature In addition standard size 25 mm witness samples which were coated during the filter run were scanned at both ambient and cryogenic temperatures and the difference between them was used to correct the ambient WHIRC filter parameters to their calculated cryogenic values Because broadband filters often have oscillatory behavior in their transmission curves and narrowband filters of 1 fractional bandwidth rarely have a truly flat region at their peak transmission and may have broad wings the definition of average transmission can be a matter of judgment For the purpose of this table we calculated the integrated transmission under the ambient filter curves and divided by the vendor calculated cryogenic FWHM of the filter to derive the number listed as average transmission Since the product of these is actually used in throughput calculations this is a somewhat artificial definition but the FWHM is an important parameter particularly for the study of high redshift emission line targets 3 2 Signal and Background Levels Table 3 1 below gives the signal and background levels obtained with WHIRC in March T 4 C and September 2008 T 23 C in units of ADU s The CN and CO w data were obtained in February 2012 shortly after their installation WHIRC User s Manual Version 1 13 2013 October 18 6 Table 3 1 WHIRC Filter Characteristics mag March Sept Bry O w l 220 03 C 19 Fe II 4500 km s 1 668 0 0
66. n and proceed However prior to starting observing it will be necessary to exit the MOP and restart it after the XTCS has been initialized 8 2 Problems Encountered During Observing Problem The first image appears to be filled with horizontal structure and has a value near 0 Solution The detector array may not be biased Check the Detector Biasing window and verify that the detector power and bias procedures have been carried out The value of Vdetcom should be 1 0 and VrstUc 0 279 If there has been no activity for two hours or more the detector will automatically debias as a safety measure and it is necessary to power and bias the detector again The detector will also automatically debias if the temperature exceeds 105 K Problem The first image appears bright with funny structure even though the OPAQUE filter is in place Solution This is actually normal behavior It can take several images for the transient effects of powering and biasing the detector to flush out We generally recommend taking 15 20 short 5 s dark frames at the beginning of the night and using no more than the last 10 for noise analysis Problem The flux levels obtained during flatfield observations are not 10000 ADU for the recommended lamp settings Solution The recommended lamp settings are guides so deviations at the 10 level can be caused by changes in the lamp output since the observations recorded in the manual were made The outpu
67. n the MOP as they would revert to those in the script once the observing started However the target name in the MOP will not be changed One approach is to generate a generic WHOMP script with the desired pattern then copy it to a scratch script which can be edited to change parameters For example consider the 2 x 2 standard star dither script shown in Fig 5 26 but stored with a generic name such as n1 or ir If one opens up the script nl obs in the former case with an editor one will find a series of four telescope motions and observations each of the sort offsetScope adjust 15 00 15 00 rotatorAngle 2 47e 16 observe n1_0 50 Object 1 The telescope offsets rotator angle and the observing sequences can be edited to carry out a variety of observations 5 7 1 Coordinate Systems in WHOMP Scripts In general when one offsets the telescope to a new target 1t may not end up centered exactly on the array If this is important for example if one wants to run a dither script with the target symmetrically positioned about the center of the array one can determine the offset of the star from the array center using the ruler task in the ds9 display and ask the OA to offset the telescope appropriately It 1s a good idea to take another exposure to verify that the star is now centered This can lead to problems if one does not understand the nuances of the telescope commands in the WHOMP scripts 1 The offs
68. name GLM GC setupZ ob GLM GC setup2 obd Save Save Map Repeat 1 ky Dither Designer Map Dither Design Fies of type Cancel y 1 v offset deg F Number of X Dithers Number ot Y Dithers Shape Selector Number ot X bithers Number of Y Dithers Shape Selector 2 Grid 2 2 Grid a mu Gk pai mig Plus X Dither Size arcsec Y Dither Size arcsec sa x X Dither Size arcsec Y Dither Size arcsec a 30 30 be _ ME _ EE e _ ME Dither Repeat 1 Exposure time s 20 Dither Repeat 1 Expose Repeat 1 Exposure time s 20 p Figure 5 28 The menu for saving the script in the subdirectory home observer observing scripts OOA X WHIRC Map Designer File Recipes View WHOMP Version 1 82 20 Oct 2010 Target Name Moose_Nebuld Target Coordinates Heliocentric lt r Coordinates wi 4 Equatorial Right Ascension H io 0 000 S Ecliptic Declination 0 D 0 f 0 000 Galactic Roll oD g 0 000 Equinox 2000 Map Designer Number of X Cells Number of Y Cells Shape Selector 3 3 Grid LS LS Plus X Cell Spacing arcsec Y Cell Spacing arcsec a 160 180 7 O E eee Map Repeat 1 Sky Dither Designer Map Dither Designer X Offset deg A Y Offset deg A Number of X Dithers Number of Y Dithers Shape Selector Number of X Dithers Number of Y Dithers Shape Selector 2 2 Grid 2 2 Grid f a LS LS Plus X Dither Size arcsec Y Dither Size arcsec x x X Dither
69. or offset of 0 0 1 e the dither pattern is aligned to the rows and columns of the array Other standard scripts have been added see Fig 5 23 these are variations on those described above and should be self explanatory WHIRC User s Manual Version 1 13 2013 October 18 34 File Dave Y Load Observing script Unload current script a load std 3x3 El load std_3x3 o0arcsec load std 5x5 100arcsec load std 5 Darcsec db load sid x5 100arcsec load std x5 oQarcsec load std 5 S0arcsec load std 5 Sarcsec load std 5 Sarcsec load std 5 15deq s0arcsec load std 3x3 J30arcsec load std 2x2 20 Exit PAG WHIRC Filters LOW AIR HE BR G FE N 4500 Fowler 1 WHIRC 7 Fowier 4 Readout se Modes Min Exposure secs 3 0 x Monsoon Camera Control whire Comms Opts PAN Help target Alpha Muti ra 0 92 25 566 dec 02 0 9 606 observer Charman propid 0124 O0866 Se St So z werwrte files 10 type Object number 1 KS CO w it H2 BR_G 4500 FE Il CH PA B Figure 5 23 The MOP File pull down menu for loading canned or custom observing scripts WHIRC User s Manual Version 1 13 2013 October 18 35 2 Below is an example of the MOP after the 5 point cross dither pattern script was loaded Note that the Observe button is now labeled Run Script To run the script through without stopping push on Run Script Or you can push on Step Script to step through useful for the f
70. past fixes are no guarantee of future performance This section will continue to be updated as our knowledge base expands 8 1 Problems Encountered During Startup Problem The observer terminal has unfamiliar windows and the WHIRC toolbar is absent Solution If Hydra Bench has been in use the computer for those instruments is still active One should quit these processes verify that the login session on wiyn 2 is observer upper right corner of screen and start WHIRC from the icon on the wiyn 2 monitor Fig 5 1 At the same time the OA should ensure that the DHE is powered up the fibers from the DHE to whirc pan are properly connected and whirc pan 1s running Problem Error messages in the pan window on startup Solution There are numerous possible problems depending on the nature of the error message A message usually in the panDaemon or panCapture window of the sort fxsl_recv failed or fxf usually indicates a hardware issue with the fiber connection from the DHE to the whirc pan Check that the DHE and whirc pan computer are powered up and that the fiber connection to the back of whirc pan shows a green light A message in the panDaemon of the sort First Read echo mismatch might indicate that the DHE is not talking to the whirc pan As a first step close down the PAN window execute the Stop PAN perhaps two or three times then Start PAN again If the message repeats close down the PAN window
71. pts to begin at the initial point as a check on the telescope pointing There is no problem with this as long as the relative offsets all add up to bring the telescope back to the initial position at the end of the script However one must not end the script with an observation at the initial position For some reason ending a script with an observe rather than an offsetScope command will leave the MOP in an observe condition and may automatically unload the script without notifying the observer In addition offsetScope arguments must have a number to the right of the decimal point e g 10 0 An argument such as 10 will not work 5 7 4 WHOMP Features There are a few features of the current version of WHOMP which observers need to keep in mind Most of these are associated with entering coordinates in the RA or DEC fields for displaying the dither pattern on the ds9 to check for guide stars or problems e The X and Y offsets for the Sky Dither Designer are not consistent A positive X offset moves the field South on the ds9 display but generates telescope offsets to the East Moreover the RA offsets are uncorrected for the cos factor as noted above A positive Y offset moves the field East on the ds9 but generates telescope offsets to the South e The Roll parameter for entering a rotator angle offset appears to be in degrees West of North opposite to the accepted astronomical convention WHIRC User s Manual Ve
72. re two fundamental differences between optical and infrared imaging which drive the observing techniques which are used in the latter e The background from the sky is significantly larger in the infrared than in the visible In the J and H bands the background is primarily from atmospheric OH emission and in the K band thermal emission from the telescope and WTTM optics increases rapidly with wavelength As a result the sky background will usually be far larger than the astronomical signals which one is trying to measure with the exception of the CN Low Airglow and He I narrowband filters e Unlike CCDs which read out by scanning the charge across the array to a readout amplifier infrared arrays are based on unit cell architecture in which each pixel is independent of the others Sensitivity and dark current can vary from pixel to pixel on the array The first of these suggests that the technique of flatfielding a raw image to yield a constant flat sky level is insufficient since even small errors in the flatfield function would yield residual structure larger than the signals of interest Therefore one must subtract as much of the background as possible as part of the data reduction The existence of isolated dead insensitive or hot pixels will compromise the measurement of any source which happens to fall on one of these pixels WHIRC User s Manual Version 1 13 2013 October 18 45 Both of these problems and others are a
73. rget on ds9 or Sky Dither on ds9 the dither mapping patterns will be superposed on a Digital Sky Survey field displayed on the ds9 The position angle of the detector on the sky may be rotated by entering the desired offset angle in the Roll field but currently this seems to be in the opposite sense to the normal astronomical convention of degrees E of N Figure 5 26 shows an example of a small dither script for the standard star FS29 The Dither pattern is a 2x2 box with 20 arcsec separation The exposure time for each dither position is 20 s and only one cycle of dithers is done No mapping 1s done so Map Repeat is set to 1 and the number of mapping cells is set to 1 in both X and Y No sky only dither positions are done so the Dither Repeat in the Sky Designer section is set to 0 the default value The shape of the dither pattern is shown as colored outlined boxes on the blue screen four of them for this particular pattern NOTE The Target Name should have no spaces since it becomes the default file name Xx WHIRC Map Designer File Recipes View Help f SN ij a 4 Equatorial Right Ascension 0 H o M 0000 S da Ecliptic WHOMP Version 1 82 20 Oct 2010 Target Name F523 Target Coordinates Heliocentric Equatorial Coordinates Declination 0 D gg 0 000 w Galactic Roll oD o 0 000 Equinox 2000 Map Designer Number of X Cells Number of Y Cells Shape Selector 1 1 Grid j LS Pl
74. rheads on operation since the guide probe must move after each telescope motion On the other hand if one is using relatively long gt 60 s frame times the overhead is small and the benefits of better image quality particularly if the native seeing is good are worth it Standard star or bright target observations utilizing 5 20 s frame times are not worth the overhead in WHIRC User s Manual Version 1 13 2013 October 18 48 guide star acquisition and probe motion If one is using WTTM one is always actively guiding but using the WTTM and not the IAS guide probe Section 7 NOTE Under conditions of significant wind buffeting using WTTM can produce significant improvement in image quality even for standard star or short integrations This is a clear strength of WTTM in helping overcome the inherent vulnerability of the WIYN telescope to wind shake due to the relatively light weight of the telescope and its large cross section within the dome slit An important consideration whether guiding with the IAS or WITM is the limited physical range of the guide probe When executing a dithering script one must ensure beforehand that the guide probe will be able to follow the guide star throughout the entire range of the observation One may ask the OA where the guide probe is located with respect to its limits and if necessary select another guide star which is closer to the center of the field Carrying out a very large map with a sing
75. rsion 1 13 2013 October 18 44 6 0 Observing Strategies Imagers and spectrographs utilizing infrared arrays have been a part of the astronomical toolkit for over 20 years and most experienced observers are familiar with the techniques used for infrared observing For novice observers the book Astronomical CCD Observing and Reduction Techniques ASP Conference Series Vol 23 1992 ed Steve Howell remains a good introductory text with a chapter describing the use of infrared arrays on page 258 The comments presented here will be a brief summary of general strategies with specific recommendations for WHIRC These strategies are a combination of common sense infrared techniques and lessons learned during our experience with WHIRC on WIYN and should not be taken as hard and fast rules Depending on factors such as the conditions temperature seeing clouds science fields sparse crowded or extended objects and filters broad or narrowband variations on the basic observing strategy may be desirable In the time since the article referenced above was written significant advances in infrared detector technology have transpired The 2K x 2K detector in WHIRC is comparable in size to CCDs in use the dark current is negligible and the read noise while high by CCD standards 17 e in Fowler 4 mode is sufficiently low to permit background limited operation even through most of the narrowband filters 6 1 IR Strategy in General There a
76. s displayed on the observer s monitor as a 4 panel status window After a successful initialization the window may be minimized with the button to reduce clutter although it is a useful diagnostic if kept open the right hand portion of the right monitor 1s a good location a If error messages occur on the PAN windows close the PAN window and single click on the Stop Pan button to clear out any malfunctioning processes Single click the Start Pan button again An error of the type first read mismatch in the panSaver window can occur in the initial startup and may be ignored if it is the only error message b If this does not clear up the problems repeat one or two more times Refer to section 8 Troubleshooting if errors continue c NOTE Error messages containing fpx indicate fiber connection errors If these recur during repeated attempts to initialize the PAN there may be a hardware issue with the fiber connection between whirc pan and WHIRC OS ionsoon whirc pa i C Fj sed alt in M Y Del New Connection Save Connection Options Full Screen Ctrl Alt Del end F tch Fil Chat Connection Info Encrypt panDaemon whirc pan panCapture whirc pan FDEGA Starting panCapture DBG panMemInitNotDaemon attached _panMemP Oxb7f75000 FDEG panImgBufferInit create 0 FDEG panCapture After detlnit status 0 FDEG In Child Starting panTriggerExp process 0 DIEG panDaemon starting
77. separate set of WTTM GUIs from the client GUI Fig 5 10 7 5 at the observer s station will appear on the OA s terminal and be used for the guide star acquisition and WTTM activation FWHM arcsec FVVHM arcsec 0 6 0 8 1 1 2 1 4 0 6 0 8 1 1 2 1 4 16 Tip Tilt 7 Open Loop Median 0 64 arcsec Median 0 77 arcsec Median 1 04 arcsec WIND 20 mph no buffeting FWHM arcsec 0 5 10 15 20 25 5 10 15 20 25 30 Image Image Figure 7 2 Results of two tests to measure the FWHM improvements from turning on WTTM correction using 10 s exposures in the H band The results are consistent with the predicted improvements of 0 1 0 15 arcsec and even more significant when wind buffeting is a factor Courtesy C Corson and H Schweiker WHIRC User s Manual Version 1 13 2013 October 18 53 7 2 Using WTTM 7 2 1 Guide Star Selection Observers are reminded that WTTM is essentially a fast guider typically operating in the 100 150 Hz range Stars which may seem bright in a deep CCD image of a galaxy field may be too faint for WTTM guiding Figure 7 3 is a plot of the APD count rate as a function of guide star brightness on several commissioning nights Under good seeing conditions lt 0 8 arcsec FWHM one can use WTTM on guide stars as faint as 15 0 but at this limit focus drift or light clouds can cause the guider to lose the star We recommend R 14 5 as a practical faint limit under good seeing conditions In
78. since the cause is often some sort of low level confusion The error messages in the PAN window can be a guide to the nature of the problem but the solution will almost always require shutting down the MOP and restarting or carrying the restart to a more basic level until the system comes back to life again A good initial step is to check the fiber link between the PAN and the DHE using the PAN DHE Loop Test from the PAN pull down menu As explained in Section 5 this will send 50 writes to the DHE and read the responses If this fails run the Reset Pan DHE Fiber Link Test from the same pull down menu This will check the status of the link WHIRC User s Manual Version 1 13 2013 October 18 61 and if it is down reload the drivers 1f it is up it will clear any junk bytes from the link After doing this it is a good idea to run the PAN DHE Loop Test again Try taking another image with the MOP If problems still occur try recycling the MOP Open up the Detector Biasing window if iconified debias and depower the detector as at the end of the night and close the window Shut down the MOP from the File pulldown menu if closing the Bias window did not automatically do this Then restart the MOP with the Start MOP button and after it has completed loading power and bias the detector from the Detector Biasing window Unfortunately the information in the MOP will be lost and you will have to retype the information in the various windo
79. strongly recommend taking a series of 10 or 20 darks OPAQUE filter with 5 s frame time during the afternoon as a check on the noise performance This is also useful to WIYN in its program of long term monitoring of instrument performance For generating sky flats a series of 10 to 20 darks at the integration time used for the science observations 1s required 6 2 6 Focus WHIRC has no equivalent to the focus routines used with CCDs because one cannot produce multiple images at different focus values on the detector in a single exposure Rather one must take separate images at different focus values and determine the best image by inspection One will generally want to start well out of focus then step through the focus values by steps of 15 to 20 until one 1s equally out of focus on the other side Because of the off axis WITM optics the focus behavior is not symmetric It should then be possible to iterate around the best focus with smaller steps as small as 5 units when seeing is good The focus of WIYN will change with temperature so one should monitor the image quality while observing and touch it up if necessary in general the focus readout value must be increased as the temperature drops If doing a long sequence of relatively short integrations one can try bumping the focus by 10 to 15 units and monitoring the improvement or lack thereof while continuing to observe and iterating while taking data sometimes this is more efficient t
80. t 2 01 p iUi Se detector UUTS 4 crror UUU UUl hcater State IDLE sp qoal 070 ZOOO sp 070 5008 0 detector 0070 501 error 0000 001 heater 0000 oa Debug Info Filter 1 Hiter z LS460 Gurs ler Figure 5 2 WHIRC Engineering GUI which is displayed on the OA monitor The four tabs are described in this and succeeding figures WHIRC User s Manual Version 1 13 2013 October 18 b The Filters tab shows the location of the filters and provides detailed information on the gaussmeter readings Homing and resetting commands can also be performed here NOTE As with all the windows on the OA screen this is for engineering level debugging and not to be used by the observer for changing filters The observer should use the MOP for all instrument operations Filters Options Temperature Control Temperature Status WIYN Staff use Only When 1 Wiel 2 Oppa Opn oH A Ail us Rr y 450M km w Ks ye Br y w CO Fe IN 4500 kmis w Love Airgluer x Fe IN w Mel u Pa amp 4500 kunfs Open v Tas filter NANDE filler arr A CWL An gem A CWL 15 um AAFAA an AAA inna N FWHM 0 0 am FWHM 1000 0 mm degrees 0 degrees 0 steps 0 steps 0 gauss 660 1 G gauss 822 1 G detent ENE detent ENE status ok atahis ok SAW error ok Aw errar ok Hernan Hi new Hirsel Hisa l dain a a E a Heset Gaussmeter opposite
81. t will slowly decrease with time since the last lamp replacement However a significant deviation could indicate either that the telescope is not pointing properly at the white spot or the proper WHIRC filter did not move into the beam Ask the OA to visually verify the telescope pointing and check that the high flatfield lights are selected Try moving to another filter and ask the OA to monitor the filter position on the Engineering GUI 1f the filters are not moving properly ask the OA to carry out the reinitialization described above WHIRC User s Manual Version 1 13 2013 October 18 60 If observing in Fowler 4 mode remember that images are coadded so that the desired raw signal level is 40000 ADU for an integration time of 16 s Problem The image readout does not complete The orange Countdown Window remains open Solution These can be the most annoying failures since they occur during the observing process at the end of a sometimes long exposure The most common failure occurs with the Countdown Window displaying Read DHE and usually indicates either a breakdown in communication or asynchronous commands which have somehow worked into the sequence Post observing analysis of the logs suggested that many of these hangs were the result of multiple observing commands a defect in the mouse which sends multiple clicks could cause this The MOP has now been locked out to avoid any commands when an observation is in
82. tailed information about a command tape velp commend To run a commend cr load a package type its name Type bre to exit a packege cr logout to get out of the IL Type nene to find out what is new in the version of the systen you are usine The Following commends cr packages are currently defired clpackage t clpackaces language obsolete stadas utilities datalog listsr Plot system bre macred proto tables images nnan ant tant s Inert PyRAF 1 dev 2006Nar24 Copyrigh Lc 2002 AURA Python 2 5 1 Copyright ic 2001 2007 Python Softuare Founcatior Fython CL command line wrapper Help cescribez executive commands ee a Figure 5 13 PyRAF shell window for data analysis WHIRC User s Manual Version 1 13 2013 October 18 a 7 Check the Detector Temperature reading on the WHIRC Detector Biasing window The light should be green and indicate a temperature of 78 5 K The Voltages light should also be green and the window should show a listing of the voltage readouts the desired value and the tolerance window generally 0 15 v If a voltage is out of tolerance the detector will not power or bias Ask the OA to check the Engineering GUI and if there is a problem call for assistance BA Temperature 0078 501 K Voltages ok _ Power Detector _ Bias Detector Reset Temp Monitor Update Voltages X WHIRC Detector Biasing Oct 26 13 22 26 whirc_bias check Bias_Tel
83. the field of view typically 100 180 arcsec for the 202 arcsec field of WHIRC and are used to generate maps of extended fields while leaving some common field overlap to match adjacent fields The default map setting on bringing up WHOMP is 1x1 a single point so one must select a map pattern using the slider bars Each of the map positions will include a dither set Sky For extended or very crowded fields it is necessary to move the telescope to a relatively nearby sparse field to obtain the sky measurements The WHOMP default is to assume no sky observations Dither Repeat 0 so this parameter must be explicitly set to I or more if sky observations are desired If both dithering and mapping are also being done a set of sky observations is carried out for each of the map positions but at the same sky location 1 e the sky offsets do not track the mapping offsets WHIRC User s Manual Version 1 13 2013 October 18 38 l ADA Open the WHOMP GUI to set the observing parameters for the script The Recipes pull down menu can be used to select template values for a single exposure dither map 1x1 sky repeat 0 single map dither 1x1 map 3x3 sky repeat 0 map dither sky repeat 0 or map with dither sky sky repeat 1 The View pull down menu can be used to view a graphic representation of the target or sky dither pattern If coordinates are entered into the Target Coordinates boxes and one selects Map Ta
84. tions of the IR standard FS 28 at the current bias level of 0 7 v The sky background levels in ADU s pixel were measured in March and September 2008 at ambient temperatures of 4 C and 23 C respectively The background in the K band filters is dominated by thermal emission and can be expected to vary significantly with temperature In addition the background in the other filters except for the 1 06 and 1 082 um narrowband filters is dominated by OH airglow which can vary a factor of two from the values listed in Table 3 1 Links to tracings of the individual filters can be found on the WHIRC website http www noao edu kpno manuals whirc WHIRC html The three broadband filters are standard J H and Ks filters The narrowband filters include those for He I H II regions PNe Br y and Pa B ionized gas Fe II photodissociation regions and PNe H2 S 1 shocked molecular gas CN and CO cool stellar atmospheres In addition Br y and Fe II filters redshifted by 4500 km s are used to provide continuum images for emission line imaging in those filters or for observing these emission lines in redshifted galaxies Finally a filter near 1 06 um 1s located in a region nearly devoid of telluric OH line emission for very low background deep imaging The current CN and CO w filters were installed in January 2012 in place of the redshifted Pa and narrow CO n filters Note The actual WHIRC filters were scanned by the vendor only at ambient te
85. to the science field The WTTM guide field Fig 6 1 is only slightly larger than the WHIRC field of view so it can be used only for mapping small regions depending on the location of the guide star with respect to the field center Offsetting to a sky position with WTTM is likely to be impossible because of the limited range WHIRC User s Manual Version 1 13 2013 October 18 49 WIYN IAS Guide Field WTTM Deployed 840 720 600 480 360 240 120 0 120 240 360 480 600 720 840 Unvignetted Focus Probe Field Unvignetted Guide sss Probe Field SS Vignetted Field North RRERRRAS RR CR RR ERES SS IAS Y Axis arcsec South 840 720 600 480 360 240 120 0 120 240 360 480 600 720 840 West IAS X Axis arcsec East Figure 6 1 Schematic of the IAS guide field with WI TM deployed Vignetting is from the WHIRC WTTM pickoff mirror which is in front of the guide probes 6 2 4 Flatfields Flatfield observations are necessary to calibrate the pixel to pixel variations in the detector array This was discussed in more detail in Section 3 5 In general we recommend that flatfields be obtained each night for each filter used for observing These can be done in the afternoon and do not require the telescope control system to be running We recommend taking at least 10 images with the flatfield lights illuminating the dome screen and the same number with the lights turned off using the intensity settings in Table 3 2
86. ug issues when observations do not work 80 6 NI MOP Hay 20 11 32 31 1112460 Hay 0 11i32 31 iiuhircd Hay 20 ld 32131 ttwhirc Hay 20 ddl 32131 ttwhirc Using network sound Running with real hardware init complete init complete commanding 11 null primer command init complete Please wait for WITH module to load WITH module loaded Uk HHHPHEHHHHEPHHEEHEREH HEE EHH ESE HH HH SESH RE HH EE EH This is the MOP command line intended for engineering and debug use only Do not type anything here and do not exit this xterm just leave it in it s iconified state HEHEHE HH HH HSE HH PSHE EHH SEHR HH EH Ml Figure 5 8 The MOP debug log window automatically loaded with the MOP c MOP status window Similar in appearance to the MOP debug this window logs filter motions and flags such as enabling disabling WTTM guided dithers a oO a e MOP debug log ise ppxGetAvP expvectorst socket got gt OK ppxGetAVP Success Wh explector 65 000 lt 0 00000041 gt lt s gt ppxGetAvP digfhvgs socket got gt OK ppxGetAVP Success Wh digHwgs 4 000 lt 0 lt 00000004 gt lt ise ppxGetAvP expyectorst socket got gt OK ppxGetAVP Success Wh explector 65 000 lt 0 00000041 gt lt ise ppxSetMode fowlerl mod socket got gt OK ppxSetMode Success Sh Restored attribute values from Monsoon fcefg _whirc fowlerL mod lt ise ppxGetAvP expvector st socket got gt OK ppxGetAVP
87. uia in 58 8 1 PROBLEMS ENCOUNTERED DURING STARTUDP cscccceccececcececcececeececscecssecesesceceseecscecsescasescess 58 8 2 PROBLEMS ENCOUNTERED DURING OBSERVING cccsccsccceccecceccecesceccecescescestectscescescesesceseasceses 60 8 3 GUIDING OR DITHERING PROBLEMS cet seoded ce acsacanrheratceets sees bata ese deed eee 63 Acronyms and Abbreviations DHE Detector Head Electronics MONSOON system FITS Flexible Image Transport System image standard GUI Graphical User Interface IAS Instrument Adapter System MOP MONSOON Observing Platform PAN Pixel Acquisition Node computer controls MONSOON OA Observing Associate TCS Telescope Control System WHIRC WIYN High Resolution InfraRed Camera WIYN Wisconsin Indiana Yale NOAO Observatory consortium WHOCS WHIRC Observation Control System WHOMP WHIRC Observation Manager and Planner WTTM WIYN Tip Tilt Module WHIRC User s Manual Version 1 13 2013 October 18 2 WIYN High Resolution Infrared Camera WHIRC User s Guide 1 0 Introduction The WIYN High Resolution Infrared Camera WHIRC is a near infrared 0 9 2 5 um imager which installs on the WIYN Tip Tilt module WTTM port The 0 1 arcsec pixel scale and 3 3 arcmin field of view are designed to take advantage of the excellent native seeing at the WIYN site and the near diffraction limited image quality 0 2 arcsec which WTTM is expected to deliver in the 2 micron band A selection of wide and narrow band filters al
88. us X Cell Spacing arcsec Y Cell Spacing arcsec x 180 180 vw i ME A Map Repeat 1 Sky Dither Designer Map Dither Designer X Offset deg 1 Y Offset deg 1 Number of X Dithers Number of Y Dithers Shape Selector Number of X Dithers Number of Y Dithers Shape Selector 2 2 i 1 Grid Grid azi zaw x E EE us Plus X Dither Size arcsec Y Dither Size arcsec x X Dither Size arcsec Y Dither Size arcsec 20 20 di 20 20 y X AA E A Dither Repeat 1 Exposure time s 20 Dither Repeat 0 Expose Repeat 1 Exposure time s a Figure 5 26 The WHOMP GUI setup for a standard star dither pattern Note that the Map is a single point and the Dither Repeat 0 There should be no spaces in the Target Name WHIRC User s Manual Version 1 13 2013 October 18 39 3 Below in Fig 5 27 1s an example of a script used to image the Glimpse Globular Cluster GLM GC This script has dithering on source with a sky offset to a blank region on sky which is dithered in the same manner The target dither pattern is repeated only once with a 2x2 box pattern and a 30 arcsec grid separation The offset sky position is 0 1 degree in X and 0 1 degree in Y where positive X is South and positive Y 1s East on the sky and a 2x2 20 arcsec grid box dither pattern is performed Note that the Dither Repeat has been set to 1 The observing script parameters are saved as a file called GLM GC setup2 obs in the home observer observing scripts subdirectory F
89. which comes from multiple reflections of the diffuse background from the sky or telescope pupil The WHIRC pupil ghost is significantly more prominent at longer wavelengths Figure 3 3 shows flatfields in the J and Ks filters the pupil ghost can be seen in both but is much more evident at the 25 level in the Ks flat than in the J flat 5 It is important to realize that the higher signal level from the pupil ghost does not represent a real increase in the array sensitivity in that region so using an uncorrected flat will result in photometric errors on the low side for sources within the ghost region We have developed a procedure for removing the ghost using the IRAF mscred rmpupil task and tests suggest that this procedure eliminates the effects of the pupil ghost Cautious observers can utilize scripts which avoid the central portion of the array WHIRC User s Manual Version 1 13 2013 October 18 9 2000 4 0 4000 6000 6000 10000 12000 14000 16000 16000 2000 5000 10000 15000 20000 Figure 3 3 Flatfields at J left panel and Ks right panel showing the central enhancement from the pupil ghost The ghost is more prominent 25 at Ks than at J 5 The falloff in intensity at the top and bottom of the array is a real sensitivity feature The black columns on the right of each image are reference columns and are not part of the 2048 x 2048 image System Architecture The basic WHIRC system architecture 1s illustrated
90. with WHIRC is essentially complete although we have had occasional problems with the X Y stage Regular exercising of the stage appears to increase its reliability As of September 2013 problems have been identified in the tip tilt stage and we do not recommend use of WTTM at present 7 1 WTTM Description A layout of the WTTM optical system is shown in Figure 7 1 taken from Claver et al 2003 SPIE 4837 438 to which the reader is referred for more details on the design and construction Two modifications to the original SPIE figure are relevant to operation with WHIRC First the ADC prisms are not used with WHIRC Secondly the beamsplitter in front of the WHIRC mounting port which was used to transmit a fraction of the light to the tip tilt error sensing quad detector when WTTM was employed with a CCD has been replaced by a dichroic since the quad sensor and WHIRC wavelength ranges are exclusive This increases the sensitivity of the quad sensor which now receives almost all of the optical light to R 15 5 under good seeing conditions W i i Intermediate Focus WTTM Pickoff oo gt Mirror lik M1 mi Mini Mosaic 4096x4096 CCD WHIRC Figure 7 1 Schematic of the WI TM optical system from Claver et al 2003 The ADC prisms are not used with WHIRC The beam transmitted through the dichroic goes to the APD error sensor WHIRC User s Manual Version 1 13 2013 October 18 52 One should keep in mind th
91. with another on a sky field 6 arcmin distant Relatively small amplitude dithering on the source field will maximize the field common to all observations See section 6 2 3 on guiding strategies 6 2 2 Integration Time There are no hard and fast rules regarding appropriate integration time for a particular observation Source brightness seeing filter and observing efficiency all come into consideration In general one will want to use an integration time sufficiently long to achieve photon noise limited operation either from the source flux bright targets or the sky background faint targets One will also want to keep the peak signal from either the source or the background well away from saturation so that the linearity 1s well behaved a good rule is lt 25000 ADU e Standards and bright targets The numbers in Table 3 1 can be used to estimate the expected integrated signal from the source The peak flux will of course be very dependent on the seeing we have found that for images with FWHM 0 5 arcsec the peak pixel flux is 0 03 of the integrated signal However a brief episode of 0 4 arcsec seeing will double this value so one should be somewhat conservative when the seeing is good Keep in mind that the minimum integration time is 4 s so standards should not be much brighter than 10 0 for broadband observations in good seeing By the same token it is preferable to use standards which can be observed in short integration tim
92. with the File button menu and select Unload current script X Monsoon Camera Control Script loaded File Comms Opts PAH Help Exposure type Object target Alpha Muti ra 02 53 34 074 Exposure in seconds aa ES 55 E Nurber of frames 1 epa armar idataldata01 Mar 12 propid 20124 0666 Fila name night 46 Pause E Automatic display J Oweruwrnte files observe name nIghtl exposure 30 type Objact number 1 Observing script Mome fobserverfobservying scopts std_ 5 o0arcsec obs Executing observe gui image name gui exp time gui exp type gui num_ frames Hext command offsetscope adjust 0 0 50 000 OPAQUE KS CO w LOW AIR HZ BR G 4500 BR_G FE_Il CN PA B zit FE Il 4500 Fowler 1 WHIRC E Fowier 4 Readout ES Modes Min Exposure secs 3 5 Figure 5 25 The MOP with an observing script in progress WHIRC User s Manual Version 1 13 2013 October 18 37 5 5 Other MOP Functions The PAN pull down menu has a number of functions which can be useful for troubleshooting e Bias Tool If the Detector Biasing window has been iconified this will reopen it and bring it to the front e DHE Loop Test This will perform a loop test of the communications between the MOP and DHE It will send 50 writes to the DHE and read the 50 responses If any one of the write read fails the test fails and one should perform the Reset pan DHE Fiber Link task e Reset PAN DHE Fiber Link
93. ws If this does not restore operation it will be necessary to shut down both the MOP and PAN execute Stop PAN then Start PAN Start MOP and power and bias the detector 4 If this still does not restore operation carry the operation one step further and attempt to recover from a hung DHE 4 In the pan Daemon window enter the command ppxsetavp mcbSftReset 4 In the pan Daemon window enter the command ppxreset 4 In the pan Daemon window enter the command ppxasyncresp This level of recovery should not require a restart of the pan or MOP if the system comes back after these steps If this does not restore operation one can attempt the next level of DHE recovery 4 In the pan Daemon window enter the command ppxsetavp mcbHrdReset This level of recovery will require a restart of the pan and MOP as it does a complete reset of the DHE If this does not restore operation 1t may be necessary to physically power down the DHE on the telescope for 30 seconds then power it back again This should be done only by trained WIYN personnel and only after consultation with the Telescope Engineer or Electronic Maintenance This should be done after one has exited the MOP Detector Biasing window and PAN The Engineering GUI can be kept running Before cycling the power check the LEDs on the DHE power supply if any of them is out notify the Telescope Engineer or Electronic Maintenance After repowering the DHE execute Stop PAN and start up

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