The JKT was designed for astrometry. It has a focal length of 15 metres in the configuration which we used, with a CCD detector in a liquid-nitrogen cryostat at the Cassegrain focus. The CCD detectors have a pixel size of 22 microns, giving a scale of approximately 0.3 arc-seconds per pixel.
In 1991, the CCD detector had an array of 590 by 400 pixels, giving a field of view of 180 arc-second East-West and 120 arc-seconds North-South. At all subsequent oppositions, we used a much larger CCD with an array 1280 by 1180 pixels. This gave a field of view of approximately 360 by 300 arc-seconds.
We used the IRAF (Image Reduction and Analysis Facility) software to measure the positions of satellites and stars in the CCD frames.