NAME:
  pmcorrdr3
 PURPOSE:   (one line only)
  Correct for the Gaia DR3 proper motion bias.
 DESCRIPTION:
  This is an implmentation of the correction published in
    Cantat-Gaudin and Brandt, A&A 649, A124 (2021)
 CATEGORY:
  Astrometry
 CALLING SEQUENCE:
  pmcorrdr3,pmra,pmdec,ra,dec,gmag,newpmra,newpmdec,pmracorr,pmdeccorr
 INPUTS:
  pmra  - Proper motion in RA from the Gaia DR3 catalog [mas/yr]
  pmdec - Proper motion in Dec from the Gaia DR3 catalog [mas/yr]
  ra    - DR3 catalog position of source [deg]
  dec   - DR3 catalog position of source [deg]
  gmag  - DR3 catalog G magnitude of source
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  newpmra   - Corrected proper motion, same units as the input
  newpmdec  - Corrected proper motion, same units as the input
  pmracorr  - Correction to proper motion [mas]
  pmdeccorr - Correction to proper motion [mas]
 KEYWORD OUTPUT PARAMETERS:
 CONFIGURATION:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Southwest Research Institute based on the
     Python implmentation from Cantat-Gaudin and Brandt, A&A 649, A124 (2021)