.TH BUILD-ASTROMETRY-INDEX "1" "July 2015" "0.56" "astrometry.net"
.SH NAME
build-astrometry-index \- Create astrometry.net index files
.SH SYNOPSIS
.B
build-astrometry-index
[options]
\fB\-i\fR \fIcatalog\fR \fB\-o\fR \fIfile\fR \fB-P\fR \fIscale\fR
.SH DESCRIPTION
\fBbuild-astrometry-index\fR takes a FITS catalog table containing at least
\fIRA\fB, \fIDEC\fR, and \fImagnitude\fR columns and converts it into
an index file that can be used by the astrometry.net programs like
\fBsolve-index\fR (1).
.SH OPTIONS
.TP
\fB\-i\fR \fIcatalog\fR
Input FITS catalog: source RA,DEC, etc.
.TP
\fB\-e\fR \fIextension\fR
FITS extension to read when \fB\-i\fR is specified.
.TP
\fB\-1\fR \fIindex\fR
Share another index's stars (alternatively to \fB\-i\fR/\fB\-e\fR).
.TP
\fB\-o\fR \fIfile\fR
Output filename for index
.TP
\fB\-N\fR \fInside\fR
Healpix Nside for quad-building
.TP
\fB\-l\fR \fIsize\fR
Minimum quad size (arcminutes)
.TP
\fB\-u\fR \fIsize\fR
Maximum quad size (arcminutes)
.TP
\fB\-P\fR \fInumber\fR
Use 'preset' values for \fB\-N\fR, \fB\-l\fR, and \fB\-u\fR. The scale-number is the
last two digits of the pre-cooked index filename \-\- eg., index-205
is \fB-P\fR \fI5\fR.
.IP
\fB\-P\fR \fI0\fR should be good for images about 6 arcmin in size and
it goes in steps of sqrt(2), so:
.IP
\fB\-P\fR \fI2\fR should work for images about 12 arcmin across
.IP
\fB\-P\fR \fI4\fR should work for images about 24 arcmin across
.IP
\fB\-P\fR \fI6\fR should work for images about 1 degree across
.IP
\fB\-P\fR \fI8\fR should work for images about 2 degree across
.IP
\fB\-P\fR \fI10\fR should work for images about 4 degree across etc... up to \fB\-P\fR \fI19\fR
.TP
\fB\-S\fR \fIcolumn\fR
Sort column (default: assume the input file is already sorted)
.TP
\fB\-f\fR
Sort in descending order (eg, for FLUX); default ascending (eg, for MAG)
.TP
\fB\-A\fR \fIcolumn\fR
Specify the RA  column name in the input FITS table (default "RA")
.TP
\fB\-D\fR \fIcolumn\fR
Specify the Dec column name in the input FITS table (default "Dec")
.TP
\fB\-B\fR \fIval\fR
Cut any object whose sort-column value is less than \fIval\fR; for
mags this is a bright limit
.TP
\fB\-U\fR
Healpix Nside for uniformization (default: same as \fB\-n\fR)
.TP
\fB\-H\fR \fIbig healpix\fR
Big healpix; default is all-sky
.TP
\fB\-s\fR \fINside\fR
Big healpix Nside; default is 1
.TP
\fB\-m\fR \fImargin\fR
Add a margin of \fImargin\fR healpixels; default 0
.TP
\fB\-n\fR \fIsweeps\fR
Sweeps (ie, number of stars per fine healpix grid cell); default 10
.TP
\fB\-r\fR \fIradius\fR
Deduplication radius in arcseconds; default no deduplication
.TP
\fB\-j\fR \fIjitter\fR
Positional error of stars in the reference catalog (in arcsec; default 1)
.TP
\fB\-d\fR \fIdimquads\fR
Number of stars in a "quad" (default 4).
.TP
\fB\-p\fR \fIpasses\fR
Number of rounds of quad-building (ie, number of quads per healpix cell, default 16)
.TP
\fB\-R\fR \fIreuse\fR
Number of times a star can be used (default: 8)
.TP
\fB\-L\fR \fImax-reuses\fR
Make extra passes through the healpixes, increasing the \fB\-r\fR
reuse limit each time, up to \fImax-reuses\fR.
.TP
\fB\-E\fR
Scan through the catalog, checking which healpixes are occupied.
.TP
\fB\-I\fR \fIid\fR
Set the unique ID of this index
.TP
\fB\-M\fR
In-memory (don't use temp files)
.TP
\fB\-T\fR
Don't delete temp files
.TP
\fB\-t\fR \fIdir\fR
Use this temp directory (default: /tmp)
.TP
\fB\-v\fR
Add verbosity.
.SH AUTHOR
The Astrometry.net team. Principal investigators are David W. Hogg (NYU) and
Dustin Lang (CMU).
.SH SEE ALSO
hpsplit (1), solve-field (1)
.br
For a tutorial, see http://astrometry.net/doc/build-index.html