NAME
focusgrid - generates a grid of star images for finding telescope focus
SYNOPSIS
focusgrid
DESCRIPTION
focusgrid is a procedure usually invoked by telco to point to a
star (RA, DEC and EPOCH, must be in the environment) and then proceeds to
generate an image containing a grid of images with EXPTIME (that must be set
in the environment) at six different secondary positions (offset by .01
degree in declination). Six images are taken (offset .01 degree in ra) at
each of the secondary positions so that the effect of seeing can be
minimised. The focus is adjusted by the amount specified by the variable
FOCUS_STEP in
ait.config.
The FITS header contains the keywords TELFOC1, TELFOC2 .. which are the
secondary positions for each group of
spots.
The request may be generated by genfocusgrid and the resulting images
analyzed by
focanl.
SEE ALSO
ait.config, focanl, genfocusgrid, tserver