Observer’s Guide for QUIRC K.-W. Hodapp J.L. Hora M.R.
October 30, 1997 1 1 System Overview The University of Hawaii (UH) QUick Infrared Camera (QUIRC) utilizes a 1024 1024 pixel HgCdTe Astronomical Wide Area Infrared Imaging (HAWAII) array produced by Rockwell Science Center. This array is sensitive to radiation from 1 to 2.5 m. The reimaging optics provide a 1:1 scale, giving the pixel scales listed in Table 1 for the various telescopes and configurations. Table 1. QUIRC pixel scales Telescope UH 88-inch CFHT 0.61-m QUIST 0.
QUIRC User Guide 2 in cases where the background has been changing rapidly. It may also give better results if the dome flat was not evenly illuminated (it is difficult to achieve even illumination at the 0.6m telescope). The dark should be subtracted from the sky before division. The disadvantages of this technique are that the sky flat shows the response of the detector to the OH airglow + thermal emission. In particular, fringing may be present in certain configurations (e.g. 2.
October 30, 1997 2.2 3 Dewar Temperature The dewar now has a temperature sensor and heater. For normal operation, the temperature controller should be used to set the detector temperature to 80.0K. If the controller is not used, drifts can occur as the telescope is moved, resulting in dark current instabilities in the array.
QUIRC User Guide 4 3.1 Workstation setup The program is run from a workstation in the control room, currently io (or halley on the 88”). There is one configuration file that qcdcom reads upon startup to determine the telescope, secondary, and other information. There are four preset configuration files currently used, located in the directory /aux/inst/qconf: tel_config_06_quirc tel_config_22_f10_quirc tel_config_22_f31_quirc tel_config_cfh_quirc These files are for the 0.
October 30, 1997 3.2 5 QCDCOM Setup and Operation The qcdcom program should be run from the directory where you want your data to be written, though this can be changed from within qcdcom using the cd command.
QUIRC User Guide 6 below. This puts the program into a mode that will be appropriate for most observing, and will at least allow one to obtain “normal” images. The description of the auto command below lists the parameters to be set. The proper defaults are # resets 1, shutter on, readout on, write on, idle on, double-correlated read on, number of samples 1, chop off, dummy read on, and dither subtract off.
October 30, 1997 7 4 Writing Scripts and Taking Mosaics Any sequence of qcdcom commands can be entered into a text file (using your favorite editor) and executed by qcdcom. The command to do this is source file, where file is the filename of the command list. This allows some routine types of observations to be performed automatically, for example taking a sequence of images in J, H, and K.
QUIRC User Guide 8 positions are available for filters. These will include the standard broadband filters J, H, K, K0, and H+K. In addition there will usually be several narrowband and other special purpose filters installed. Below is a list of the current filters as of the date of this manual. These are subject to change; the most recent configuration can be obtained by using the fi command in the qcdcom program, or by checking the QUIRC WWW homepage. The focus offsets for f/10 and f/31 are also given.
October 30, 1997 5.2 9 Taking Dark Frames Since there is no blank position in the filter wheel and the shutter is warm, some extra care is required to obtain reasonable dark frames. With the installation of the second filter wheel, a “LOWFLUX" setting has been provided. This setting selects two filters simultaneously with incompatable bandpasses, e.g., the J filter and Br (2.16 m).
QUIRC User Guide 10 program is described here. 7.1 Setting up The setup file .vf-init has been installed in the home directory of the user obs. If running from a different user name, you must have this file in your home directory, as well as the *.cm files and ps proc. The program can be run by typing the following in any window: % vf & To display images automatically, one must set the data directory to be the same as where qcdcom is storing the FITS files.
October 30, 1997 11 The TCS coordinate window (under Options) can be used to center a source or move it around the array at the 88-inch. The plate scale defaults to the f/10 scale (0.1886 arcsec/pix), for the f/31 scale it is 0.0608 arcsec/pix. First move to the source and press the “f" key, it will grab the pixel location as the “From" coordinates (you may need to click left with the mouse on the source before hitting the F key).
QUIRC User Guide 12 > ll hfilei Read DSP code .lod file ll reads a DSP code binary file into the Sparcstation memory. > dl hi Download DSP code dl sends the DSP code to the DSP electronics, and then causes the DSP to start executing this code. dl also asks the DSP to recalibrate its A/D converter, which takes about 2 seconds. > du hfilei Download Utility board code du loads the utility board code. This command should be run after the DSP has been initilalized with the dl or df commands above.
October 30, 1997 > object 13 h time [ name]]i Setup for object [ object prepares qcdcom to take an exposure of a general target. You can specify integration time as the first argument and an object name as the second. The object command sets the automatic actions: # of resets: 1, shutter on, readout on. Example: object 300 N3031 (set integration time to 300 sec and object name to N3031) Example: object 0.18 (set integration time to 0.
QUIRC User Guide 14 dither subtract on/off This option, when turned on, will subtract the previous image from the current one and store the result in a file with a “chop" added to the normal data file name instead of the file number. The name is the same as the chop mode described above. This is often useful when dithering on a faint source that cannot be seen without subtracting the sky/array background from the image.
October 30, 1997 15 > fw hwheel# positioni Set filter wheel to position Set the specified filter wheel (1 or 2) to a specific position (1 through 8). For example, one would give the command fw 2 3 to move filter wheel 2 to position number 3. This command is normally not used, the fi command (see above) is used to set the standard filter positions. However, this command could be used to set some non-standard combination of filters, such as the K filter and a narrowband filter.
QUIRC User Guide 16 > name hobjnamei Set object name name is used to set the object name which will be written to the FITS header. > pupil hnum commandi Set pupil position This command sets the pupil position. If no pupil number is given, a list of available pupils are given and the current pupil position is shown. If the pupil number is different from the current, the pupil slide is moved to the new position.
October 30, 1997 > sound 17 hi Toggle fancy sounds Qcdcom will use distinctive sounds for various operations. If you don’t want to listen to them you can turn them off with the sound command. > synch hi “Ping” the DSP by sending it data and asking it to send it back. This is useful to check to see whether the controller is alive and receiving commands properly from qcdcom, or if the electronics may need a hardware reset.
QUIRC User Guide 18 Examples: oc IDL put controller in idle mode oc RDC perform detector read > diag l1 hcnt fr|cg data]i 4MHz loopback test mode. Test fiber optic interface in hardware loopback mode. Receiver is wired for operation at 4MHz, and a fiber is connected directly between the receiver and transmitter. This test runs cnt loops of 65536 words each, with values 0 through 0xFFFF. If the c option is specified, then data is a value (in hex) to be sent repeatedly.
