SI 1100S

Spectral Instruments 1100S CCD

This CCD camera is currently the main imaging instrument on the RCC telescope.

An SI 1100S camera with Johnson-Cousins B,V,R,I and Sloan u,g,r,i,z filters is currently mounted on the telescope yielding an approximately 16'x16' FoV. Camera control is implemented via ccdsh after the camera drivers are loaded. This can be done with the following command:

source /usr/local/ccdsh/scripts/load-ace-sicamera.ccdsh

This line can also be included in the user's local startup script in the home directory. The camera driver file contains the followings:

module mod_sicamera.so
module mod_ace_filter.so

define  filter  1       B       "Bessel B"
define  filter  2       V       "Bessel V"
define  filter  3       R       "Bessel R"
define  filter  4       I       "Bessel I"
define  filter  5       C       "Clear"
define  filter  6       u       "Sloan u"
define  filter  7       g       "Sloan g"
define  filter  8       r       "Sloan r"
define  filter  9       i       "Sloan i"
define  filter  10      z       "Sloan z"
define  filter  11      E       "Empty"

The first two lines load the camera and filter modules respectively, and the next eleven defines the filters.

Parameters

The basic parameters of the camera and its CCD are the following:

• Resolution: 4096 x 4096
• Pixel size: 15 x 15 microns
• Effective field-of-view: 16 x 16 arcminutes
• Effective resolution: 0.23"/pixel
• Available binning modes: 1x1
• Detector: STA-4150 Grade 1
• Gain: ~2.63 (depends on the channel)

Filters

The third column of the driver file contains the filter positions, the fourth the names which the filter can be referred to when using the set filter command, and the fifth contains the names.

Important Notes

• Camera readout is done via four channels. The gain and readnoise values are slighlty different for the four channel. Please see the quality test report below for details!
• The camera can be cooled to <math>-115^{\circ}\mathrm{C}</math> via crycooling. The cooler should operate all the time. In case of temperature increase there is a vacuum loss, which renders the camera unoperable! Please always check the camera temperature! The operating vacuum is around 0.002-0.003 torr. You can check this in the fits header, under PARAM7.
• The pickoff mirror and the off-axis guider mirrors block the light from reaching the camera. Do not forget to switch off the spectrograph: acectrl --stop, and move the guider mirror to the side: acectrl --guide-xstage-reset, before starting the observations.
• The camera can be focused with the usual set focus command within ccdsh.
• For quality test, see this document:File:1100-189 TestReport-RMA-6112-Data-.pdf
• Currently (2019.08.28), the ccdsh module for the camera does NOT support trimming and binning. Please do not attempt to use trimming or binning until further notice!
• Currently (2019.08.28), both the ccdsh module and the windows backend does NOT support image interruption. Therefore, it is advised to insert a delay=1 or delay=2 into each image definitions within the ccdsh sequence, for instance sequence -n dark 10*[dark,20,delay=2] and then interrupt the sequence (with Ctrl+C) while the system is delaying there -- in this example, for 2 seconds.

Troubleshooting:

• If the system behaves abnormally (e.g. ccdsh do not start properly or freezes before the CCD> prompt would appear), there is a high chance that the back-end software run on a Windows machine has some problems. That machine has an IP address of 172.31.171.171, it can be ping'ed from the control computer(s).
• You can check the status of this Windows program which currently operating the camera here: vncviewer 172.31.171.171. Please do not modify anything here (unless you know what are you doing). If everything goes well, you should see something like this (where the image shown in the area is usually the last frame taken by the camera) otherwise a pop-up window will likely show some error or warning messages like this or this. Such error messages are otherwise exceptionally rare (say, once in a year or so). If you are facing with such a problem, exit from the current `ccdsh` session (or use `killall -9 ccdsh` to terminate a frozen `ccdsh` startup procedure) and consult with someone from the technical team and/or another support astronomers (i.e. by writing an email to the supastron@ mailing list).

How to observe with the camera

Usage of the SI 1100S on the RCC