Quick Check Scripts


The main quality control scripts are maintained by astronomy group and are stored in /opt/astro/packages/quality. In addition to these scripts , there are some private Detector Group scripts that have been used for quick performance checks during commissioning. these scripts are stored in :

/home/dspdev/scripts

Links to these scripts are contained in the loginuser.cl files of the INTOBS, INTGUEST,WHTOBS and WHTGUEST accounts.

Currently only one script is defined ; 'gain.cl'. This takes two flat field or pre-flash image files and calculates the noise and gain using the photon transfer method. The script has been calibrated against the Fe55 X-ray technique. It requires two identical exposures, preferably windowed, containing a bias strip down one side. A format file is also required in the same directory as the images. The format file (the program will prompt you for the name) must contain the following information:

bias-strip-x-location-start bias-strip-x-location-end bias-strip-y-location-start bias-strip-y-location-end

image-area-x-location-start bias-strip-x-location-end bias-strip-y-location-start bias-strip-y-location-end

statistics-box-size-x statistics-box-size-y <RETURN>

 An example file for an EEV CCD would contain :

10 40 100 300

100 300 100 300

25 25

 Precautions :

An evenly illuminated part of the chip should be used where the exposure is at least 5000ADU.

Non-windowed images will take a long time to reduce.

Make sure the chip format file contains a carriage return as the last character.

Make sure the chip format file is in the same directory as the images and that this is the current directory.

Avoid boundary areas for selection of image and bias strip areas.

 


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