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6

QUIRC User Guide

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. All of these parameters are saved each time they
are changed, so if you have set these parameters previously, this initialization step may be skipped.

At the beginning of your run you will also want to re-initialize the filter wheel to make sure it is
in the correct position. This can be done by issuing the command

filter home

. This can take

a couple of minutes to complete. If there is any error in this procedure, try again; if the

filter

home

command does not complete successfully the filter position will be wrong.

The pupil will most likely already be in the proper position; the current pupil position is displayed
when qcdcom starts.

At this point the program is ready to start taking data.

Since qcdcom saves almost all of the

setup parameters whenever they are changed, when you quit qcdcom and re-start you can skip the
initialization steps. If qcdcom should exit abnormally (i.e. crash) for any reason, the parameters it
reads in may be old and you may need to set them again. Typically only resetting the file number is
necessary.

3.3

Taking exposures

For each object you are observing you will typically use a sequence of the commands

filter

,

object

, and

go

. The following is a quick summary of basic observing commands, but you should

read over the full set of command descriptions (given below) before you begin observing.

The

fi

command can be used to move the wheel to the proper filter. This command takes a numeric

argument between 1 and 8. The complete list is given in a table below.

The

object

command is used to set the exposure time and object name. To set up a 180 second

exposure of your favorite region, you might type “

object 180 My favorite region

”. The

name “My favorite region” will be recorded in the header as the object name.

The

go

command can then be issued to take the exposure. Qcdcom will reset the array and read

the reset level, open the shutter and take the exposure, read the array again, and write the difference
between the first and second array reads to disk. You can then display this image using your favorite
image display program.

When finished observing, the camera should be left in the IDLE mode. This mode has the DSP perform
a reset every 5 seconds to prevent the array from saturating. This mode is executed automatically
after an integration if the auto idle flag in the qcdcom program is true. Otherwise, it can be started
using the

idle

command.

Summary of Contents for QUick Infrared Camera

Page 1: ...Observer s Guide for QUIRC K W Hodapp J L Hora M R Metzger University of Hawaii October 30 1997...

Page 2: ......

Page 3: ...ith QUIRC The qcdcom program controls taking exposures and writing data in FITS format to disk operates the moving parts of the instrument such as the shutter filter wheel and pupil mask communicates...

Page 4: ...ation differences for integration times less than 1 second Therefore short exposures should be avoided particularly when exposing dome flats it is far better to dim the lights with the domelight dimme...

Page 5: ...elow assume a PSF of 0 5 arcsec FWHM Table 2 QUIRC Sensitivity UH 2 2m Telescope Filter Point SRC Mag Mag arcsec2 Jy ADU 1 sec J 18 6 17 9 1 052e 6 H 17 8 17 1 8 295e 7 K 16 2 15 5 9 622e 7 H K 18 6 1...

Page 6: ...ted image display capability A separate program should be used to display the data One option is to use the viewfits program vf This is a display program developed by Tony Denault at the IRTF that dis...

Page 7: ...ode is running The command to download the current standard DSP code is the following df quirc Occasionally the download will fail if the camera is in some undetermined state and a reset will need to...

Page 8: ...rash for any reason the parameters it reads in may be old and you may need to set them again Typically only resetting the file number is necessary 3 3 Taking exposures For each object you are observin...

Page 9: ...telescope and guide probe and turns the guider back on On the 88 this communicates with Atlas and MiniOtto over the ethernet to perform the guider movements and on CFHT commands are sent over a seria...

Page 10: ...6 H K dual 1 8 m 2 794 20 6 6 1 7 H2BP23 2 12 m 0 914 2 1 7 1 8 2260BP60 2 260 m 2 794 20 6 8 2 1 1560BP120 1 56 m 9 2 2 1710BP120 1 71 m 10 2 3 1 989BP50 1 989 m 11 2 4 1 506 60 1 506 m 12 2 6 1 107...

Page 11: ...th auto or the shutter will not open Also note that you should always do only one filter DARK followed by exactly one filter BACK always in pairs otherwise the filter wheel will get lost and require a...

Page 12: ...chop image and displayed in vf Therefore the observer can take focus frames acquire and center the object etc without saving all the images as separate data files This avoids filling the disk with use...

Page 13: ...P initialization commands In general you will need to initialize the DSP processor in the Leach electronics after power up or after a DSP reset because its cold reset state is not appropriate for runn...

Page 14: ...rform first data read of double correlation pair store image in memory 4 Turn off output amplifiers 5 Open the shutter and wait for a predetermined exposure time 6 Close the shutter 7 Turn on output a...

Page 15: ...e double correlated read on off Controls whether the device is read out before and after the shutter opening or only after If reading before and after the difference between the two are taken and this...

Page 16: ...o stay open slightly longer The exposure time recorded in the header however will reflect the true amount of time the shutter was open filter hnum commandi Set filter This command selects the filter s...

Page 17: ...fp q940811 go h num i Start exposure Go is the command to take an exposure As described above according to the param eters which are set go may reset the chip open the shutter and close it a predeterm...

Page 18: ...resulting image to a disk file set hparami n Set parameter Certain program parameters can be set or unset with this command To set a param eter for example save one issues the command set save To uns...

Page 19: ...direct access to the DSP computer hall hnloopi Read Hall sensors read the Hall effect sensors nloop times The filter wheel 1 sensor is displayed and depending on the position of the switch either the...

Page 20: ...en data is used as a seed for a random number generator and 65536 words of random data are sent per loop diag l3 hcnt fr cg data i Timing board loopback test Loopback test with timing board in place M...

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