Appendix

A1. Determining the scale and the rotation angle.

The guider sends corrections to the TCS through the gg command. The units for those corrections are pixels. The TCS scales and rotates those pixel values using the scale and rotation factors introduced by the user.

Scale and rotation factors have to be deremined empirically at the telescope. Tipically, you'll select a star, place the guide box on it and then tale note of the pixel coordinates of the box. Then you'll do an arc-second offset with the telescope and then you'll pu the the guiding box back on the star, taking note of the new position. The scale of the telescope will be one devided by the distance between the first and last position of the guiding box.

A.2 Demo software

The software sources include a set of demo programs useful for diagnostic. The README files included with each program describe how to compile and run the programs. Following is the demo programs directory tree.

• cdl
  • acq+ximtool
  • animate
  • comex+ximtool
  • cursor
  • patterns
• ic-pci
  • am-dig
  • am-std
• serial