Determine the mean pointing for the observation.
This subroutine first merges all attitude files into a
single file. It then runs the aspect FTOOL to calculate the
mean pointing. It applies an instrument to spacecraft mean
alignment file if there is one.
The result is a set of Euler angles giving the mean spacecraft
orientation, and a set of RA, Dec and Roll giving the mean
instrument pointing as offset by the alignment file.
The subroutine next calculates the galactic coordinates
corresponding to the mean instrument RA, Dec and Roll.
All of this information is logged and stored in the
This body method just calls determine_pointing
subclasses may override this to do other things.
Determine the nominal pointing after merging all attitude files.