NAME

Astro::FITS::HdrTrans::JAC - Base class for translation of Joint Astronomy Centre instruments.

SYNOPSIS

use Astro::FITS::HdrTrans::JAC;

DESCRIPTION

This class provides a generic set of translations that are common to instrumentation from the Joint Astronomy Centre. It should not be used directly for translation of instrument FITS headers.

translate_from_FITS

This routine overrides the base class implementation to enable the caches to be cleared and for the location of the DATE-OBS/DATE-END field to be found so that base class implementations will work correctly.

This means that some conversion methods (in particular those using time in a base class) may not work properly outside the context of a full translation unless they have been subclassed locally.

COMPLEX CONVERSIONS

These methods are more complicated than a simple mapping. We have to provide both from- and to-FITS conversions All these routines are methods and the to_ routines all take a reference to a hash and return the translated value (a many-to-one mapping). The from_ methods take a reference to a generic hash and return a translated hash (sometimes these are many-to-many).

to_OBSERVATION_ID

Converts the OBSID header directly into the OBSERVATION_ID generic header, or if that header does not exist, converts the INSTRUME, RUNNR, and DATE-OBS headers into OBSERVATION_ID.

The form of the observation ID string is documented in JSA/ANA/001 (http://docs.jach.hawaii.edu/JCMT/JSA/ANA/001/jsa_ana_001.pdf).

_fix_dates

Sort out DATE-OBS and DATE-END in cases where they are not available directly. This is mainly an issue with database retrievals where the date format is not FITS compliant.

Astro::FITS::HdrTrans::JAC->_fix_dates( \%headers );

REVISION

$Id$

SEE ALSO

Astro::FITS::HdrTrans, Astro::FITS::HdrTrans::Base.

AUTHOR

Brad Cavanagh <b.cavanagh@jach.hawaii.edu>.

COPYRIGHT

Copyright (C) 2007 Science and Technology Facilities Council. Copyright (C) 2006 Particle Physics and Astronomy Research Council. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either Version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.