astrom is a powerful package
which allows you to add or improve sky coordinate information to
your images, which in turn helps when you are, for example, registering
(multi-wavelength) data. However,
quite hard to use:
autoastrom tries to make it
This bundle includes a version of
generates FITS WCS headers. That
version is bundled within the
download below, but if you want, you can also get it
autoastrom(html/ps), and SUN/5 (html/ps) for
astrom application provides powerful
astrometry facilities, for analysing astronomical images; it is,
however, rather cumbersome to use. As described in SUN/5,
obtain the plate centre and plate scale of a CCD image, by comparing plate positions of objects with those in a reference catalogue, and fitting with both four- and six-component distortion models;
with enough data, obtain cubic distortion and plate tilt, using seven- to nine-component models;
if enough information is available, it will do the reductions in observed place, correcting for atmospheric refraction.
autoastrom provides a shell
astrom so that, as well as the core astrometric
work on a CCD image provided as an NDF, as long as it has at least rough astrometry (plate centre and scale);
automatically download appropriate reference catalogue information from catalogue servers supported by the SkyCat library;
insert the astrometric results into the original NDF, as a WCS component;
alternatively or additionally make the astrometry available as a set of FITS-WCS header cards.
autoastrom requires at least CCDPACK version 4.0-1
and ATOOLS version 1.5. These may already be installed on your
system, but if not should be obtainable from the Starlink
software store. If these components are installed in
non-standard places, then you need to point to them with the
ATOOLS_DIR respectively. Contact Norman if you need
autoastrom also relies on KAPPA and
EXTRACTOR, but though these should be recent-ish versions,
autoastrom isn't particularly sensitive to them.
The script can also use the matching program
Version 0.7 of this is now distributed with
autoastrom, but if you build a separate version
(newer or older), and install it in the directory
To build, give the sequence of commands
./mk build ./mk install
Although everything works on the development system, as checked out of CVS, several of these tests fail in the distribution bundle, for silly but hard to fix reasons. Thus these regression tests aren't actually terribly useful for anything in the way of checking that the build worked. Pity about that, really.
There's a pre-installation regression test
(if you haven't installed
match, a couple of the regression
tests will fail in a harmless but obvious way):
$ mkdir /tmp/autoastrom $ setenv AUTOASTROM_DIR /tmp/autoastrom # or whatever $ ./mk test-install $ ./mk pretest
A couple of regression tests fail on DUX, apparently due to rounding errors somewhere.
One of the ASTROM regression tests fails due to inadequate build-time configuration (which is really hard to fix in the distribution bundles because of the ... curious makefile conventions we have).
The regression test t/t9 (which consists of two runs of autoastrom right after each other) seems to hang on rlspc5 at RAL (though it works on my box in Glasgow), with an error which suggests that the Perl/ADAM system has got itself into a terminal fankle. I suspect that this is caused by something like the monoliths from the first run not being fully shut down before the second starts, but I don't have any more specific explanation at present.
2004 June 18