insbs: INStrument BoreSight calculation

• SYNOPSIS
  
      insbs instrument=<instr> ra=<ra> dec=<dec> apos=<apos> bstoolsout=true|false
  
• DESCRIPTION
  Given the viewing direction of the star tracker in terms of Right Ascension and Declination of the boresight + astronomical position angle insbs computes the viewing direction of the instrument specified via the instrument parameter - result is written to stdout in verbose form (default) or as a strbs command line if bstoolsout=true.

  The Right Ascension/Declination of the star tracker boresight can be entered in either of the forms

        23h59m48.12s / 45o38'14.55"
  

  or decimal degrees:

        123.23445 / 45.238474
  

  Position angles have to be entered in decimal degrees.

• REFERENCE
  See task epicbscalgen and cal documentation for definition of boresight related coordinate frames.