gastro2 is the successor to gastro. The gastro2 program determines the astrometric transformation for an image based on the cmp/smp file. This file contains both the table of object data and the complete image FITS header. Using the header astrometric information as a starting point, gastro2 loads the reference astrometry objects appropriate for the region and determines the matching objects between the image and the reference. These objects are used, with iteration to improve the sample, to determine the astrometric transformation with up to 3rd order polynomials.

    gastro filtname.cmp
    options:
      -h
      -help
      -v
      -p (photcode)
      -plot
      -maglims
      -nstars
      -fx
      -fy
      -coords (ra) (dec)
      -dump
      -mdmp
      -cdmp
      -loneos

    gastro2 configuration variables:
    OFFSET_RADIUS     - unused
    MIN_MATCHES	  - unused
    DEFAULT_RADIUS	  - unused
    MINIMUM_RADIUS	  -
    MAX_ERROR	  -
    MAX_NONLINEAR	  -
    MAX_PRECISE	  -
    CCD_PC1_1	  -
    CCD_PC2_2	  -
    CCD_PC1_2	  -
    CCD_PC2_1	  -
    ASEC_PIX	  -
    NFIELD		  -
    NPOLYTERMS	  -
    ROT_ZERO	  -
    dROT		  -
    NROT		  -
    POLAR_ALIGNMENT	  -
    GSCFILE		  -
    GSCDIR		  -
    2MASS_DIR         -
    POLAR_AXIS_RA     -
    POLAR_AXIS_DEC    -
    RA_OFFSET         -
    DEC_OFFSET        -
    LONEOS_REGIONS    -
    USNO_CDROM        -
    ASTRO_REFCAT      -
    CATDIR            -
    ROUGH_ASTROMETRY  -
    PHOTCODE_FILE     -
    GASTRO_MAX_NSTARS -