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BUILD-ASTROMETRY-INDEX(1) astrometry.net 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).

SEE ALSO

hpsplit (1), solve-field (1)
For a tutorial, see http://astrometry.net/doc/build-index.html
July 2015 0.56