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build-astrometry-index(1)

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).

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