All:
 
As the list has grown I'm duplicating the info that Michael Richmond sent today.  His work is grossly advanced and is shown at his web address:

 
http://spiff.rit.edu/richmond/occult/bessel/bessel.html
 
I do not yet have a working demo program for you but am working on it regularly as time permits.
 
In the meantime, if you like puzzles, try to count and list the parameters which must be adjusted in a given data set in order to fit the real data to the theory.  For example:

 
Distance to moon or asteroid
velocity of moon or asteroid
size of star
 
Some can be set as constants, e.g.
wavelength of light
      (probably can fix as a constant mix by sampling the spectrum)

 
Art Lucas, Sc. D., secy/treas, IOTA

BREIT IDEAS  Observatory
http://www.poyntsource.com/BREIT_IDEAS/index.htm