Positional Astronomy help needed.

[Scott S]

Hello all,

I'm a surveyor working on an Excel spreadsheet to convert FK5 positions into altitude and azimuth system. Yeah, I know there's an FK6, but one step at a time.
I know it sounds simple, right.
But I have to account for proper motion, precession, nutation, aberration, parallax, light deflection, polar rotation and refraction.
I built the sheet and got very close to the USNO values (minus refraction, of course) but I need help tightening it up.

I'm within about 30 seconds in azimuth and 10 seconds in altitude.
I used Meeus mostly, so don't recommend that, please.

If anyone would be willing to help, I would GREATLY appreciated it.

Thanks, Scott

 

[Scott S]

Found what I needed from the IAU.
SHould anyone else stumble along this way, this is the ticket;

http://adsabs.harvard.edu/full/1989AJ...97.1197K