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build-astrometry-index - Create index files


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


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 programs like solve-index (1).


Input FITS catalog: source RA,DEC, etc.
FITS extension to read when -i is specified.
-1 index
Share another index's stars (alternatively to -i/-e).
Output filename for index
Healpix Nside for quad-building
Minimum quad size (arcminutes)
Maximum quad size (arcminutes)
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
Sort column (default: assume the input file is already sorted)
Sort in descending order (eg, for FLUX); default ascending (eg, for MAG)
Specify the RA column name in the input FITS table (default "RA")
Specify the Dec column name in the input FITS table (default "Dec")
Cut any object whose sort-column value is less than val; for mags this is a bright limit
Healpix Nside for uniformization (default: same as -n)
Big healpix; default is all-sky
Big healpix Nside; default is 1
Add a margin of margin healpixels; default 0
Sweeps (ie, number of stars per fine healpix grid cell); default 10
Deduplication radius in arcseconds; default no deduplication
Positional error of stars in the reference catalog (in arcsec; default 1)
Number of stars in a "quad" (default 4).
Number of rounds of quad-building (ie, number of quads per healpix cell, default 16)
Number of times a star can be used (default: 8)
Make extra passes through the healpixes, increasing the -r reuse limit each time, up to max-reuses.
Scan through the catalog, checking which healpixes are occupied.
Set the unique ID of this index
In-memory (don't use temp files)
Don't delete temp files
Use this temp directory (default: /tmp)
Add verbosity.


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


hpsplit (1), solve-field (1)
For a tutorial, see

July 2015 0.56