Working with CIRSI

WORKING WITH CIRSI

revised 13/06/00

CIRSI consists of 4 Mercury-Cadmium-Telluride 1000x1000 pixel chips from Rockwell (arranged in 2 x 2 array with ~100% gaps) so that mosaic images can be built up. Each chip covers ~7 arcmin on the sky, each pixel is ~0.45". The chips are each split into 4 quadrants, which are read out separately in tandem, which gives the fast read needed in IR for sky calibration. The CIRSI infrared camera is not a ING common user instrument, and will at every observing run have support from a CIRSI team member
The data acquisition system & instrument comm. software are CIRSI's own, the communication with TCS is still needed through our DAS/TELD.

STARTUP PROCEDURE

Start up TCS and DAS the usual way:

Ensure that lpss15 is up running with the correct CIRSI configuration file
On lpx22 open up a telnet window and connect to lpas2
Login to lpas2 as int_login (password available in the control room)
Select from menu "start" (infodisp + user interface pops up, original window continues to be active as the telescope d-task
Login to lpss13 as intobs
SYS>obssys - select the appropriate CIRSI configuration from the menu
SYS>startobssys
SYS>setenv CIRSI ip - ip number of the cirsi controller

Three windows will pop up: INFODISP, TALKER-SYS & TALKER-TO
Also, the correct configuration will be send to the TCS, including focal station setup & aperture definitions. Check with 'show focal'
The orange UltraDAS window can be exited as it is not used.
Remember: No autoguiding is done with CIRSI !!

TV:
The 4 chip centers will appear more or less at each corner on the Finder TV, starting with chip#1 at the lower left corner and going clockwise.

PREPARATION PROCEDURE

Rotator position:
Rotator position should always be 90, corresponding to the wheels of the CIRSI mount box pointing downwards. As the rotator position is physically locked with a pin, it should be impossible to move it. (12/06/98: TCS info comes up with S/W rotator limit, just ignore it)

Telescope Focus:
Focus is around 49.1mm (13/06/00). Focus scripts are run regulary by observers.

Calibration procedure:
As the distance between rotator center and array center is unknown, calibrating is somewhat tricky. Normally, a cal last with a nightly adjustment of ap0 is the best solution (see below).

Determine Aperture offset:
Aperture offsets for each of the four arrays are automatically loaded at startup (by the startobssys command), and can be viewed by USER> show aperture. These might not be correct, so a script called CIRSILoadApertures exists (from SYS>). This sends aperture definitions to the TCS and is normally executed at the beginning of the night with the ap0 adjustment. If the TCS is brought down during the night, the apertures must be send again.

OBSERVING PROCEDURE

As no autoguiding is needed, and CIRSI do dithering patterns from scripts in a similar manner as WFC, the TO's tasks during normal observation are minimal. The main tasks will be finding suitable stars for focus determination (~12mag stars) and for aperture offset determination (~10mag stars). The easiest way is to use GSS with the option gss>con none/rmax=1200 (1200" search field)

DATA ARCHIVING

Data are written by observers/CIRSI team on own tape drives.