NAME

       build-astrometry-index - Create astrometry.net index files

SYNOPSIS

       build-astrometry-index [options] -i catalog -o file -P scale

DESCRIPTION

       build-astrometry-index  takes  a  FITS  catalog  table  containing  at  least RA, DEC, and
       magnitude  columns  and  converts  it  into  an  index  file  that  can  be  used  by  the
       astrometry.net programs like solve-index (1).

OPTIONS

       -i catalog
              Input FITS catalog: source RA,DEC, etc.

       -e extension
              FITS extension to read when -i is specified.

       -1 index
              Share another index's stars (alternatively to -i/-e).

       -o file
              Output filename for index

       -N nside
              Healpix Nside for quad-building

       -l size
              Minimum quad size (arcminutes)

       -u size
              Maximum quad size (arcminutes)

       -P number
              Use  'preset' values for -N, -l, and -u. The scale-number is the last two digits of
              the pre-cooked index filename -- eg., index-205 is -P 5.

              -P 0 should be good for images about 6 arcmin in size  and  it  goes  in  steps  of
              sqrt(2), so:

              -P 2 should work for images about 12 arcmin across

              -P 4 should work for images about 24 arcmin across

              -P 6 should work for images about 1 degree across

              -P 8 should work for images about 2 degree across

              -P 10 should work for images about 4 degree across etc... up to -P 19

       -S column
              Sort column (default: assume the input file is already sorted)

       -f     Sort in descending order (eg, for FLUX); default ascending (eg, for MAG)

       -A column
              Specify the RA  column name in the input FITS table (default "RA")

       -D column
              Specify the Dec column name in the input FITS table (default "Dec")

       -B val Cut  any object whose sort-column value is less than val; for mags this is a bright
              limit

       -U     Healpix Nside for uniformization (default: same as -n)

       -H big healpix
              Big healpix; default is all-sky

       -s Nside
              Big healpix Nside; default is 1

       -m margin
              Add a margin of margin healpixels; default 0

       -n sweeps
              Sweeps (ie, number of stars per fine healpix grid cell); default 10

       -r radius
              Deduplication radius in arcseconds; default no deduplication

       -j jitter
              Positional error of stars in the reference catalog (in arcsec; default 1)

       -d dimquads
              Number of stars in a "quad" (default 4).

       -p passes
              Number of rounds of quad-building (ie, number of quads per  healpix  cell,  default
              16)

       -R reuse
              Number of times a star can be used (default: 8)

       -L max-reuses
              Make  extra  passes through the healpixes, increasing the -r reuse limit each time,
              up to max-reuses.

       -E     Scan through the catalog, checking which healpixes are occupied.

       -I id  Set the unique ID of this index

       -M     In-memory (don't use temp files)

       -T     Don't delete temp files

       -t dir Use this temp directory (default: /tmp)

       -v     Add verbosity.

AUTHOR

       The Astrometry.net team. Principal investigators are David W. Hogg (NYU) and  Dustin  Lang
       (CMU).

SEE ALSO

       hpsplit (1), solve-field (1)
       For a tutorial, see http://astrometry.net/doc/build-index.html