NAME

Astro::FITS::HdrTrans::CGS4 - UKIRT CGS4 translations for "old" style CGS4 headers.

SYNOPSIS

  use Astro::FITS::HdrTrans::CGS4Old;

  %gen = Astro::FITS::HdrTrans::CGS4Old->translate_from_FITS( %hdr );

DESCRIPTION

This class provides a generic set of translations that are specific to the CGS4 spectrometer of the United Kingdom Infrared Telescope.

METHODS

can_translate

Returns true if the supplied headers can be handled by this class.

  $cando = $class->can_translate( \%hdrs );

This method returns true if the INSTRUME header exists and is equal to 'CGS4', and if the IDATE header exists, matches the regular expression '\d{8}', and is less than 20081115.

It also handles the reverse (to FITS) case where the INSTRUMENT header replaces INSTRUME, and UTDATE replaces IDATE in the above tests.

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_POLARIMETRY

Checks the FILTER FITS header keyword for the existance of 'prism'. If 'prism' is found, then the POLARIMETRY generic header is set to 1, otherwise 0.

to_DEC_TELESCOPE_OFFSET

The header keyword for the Dec telescope offset changed from DECOFF to TDECOFF on 20050315, so switch on this date to use the proper header.

from_DEC_TELESCOPE_OFFSET

The header keyword for the Dec telescope offset changed from DECOFF to TDECOFF on 20050315, so return the proper keyword depending on observation date.

to_RA_TELESCOPE_OFFSET

The header keyword for the RA telescope offset changed from RAOFF to TRAOFF on 20050315, so switch on this date to use the proper header.

from_RA_TELESCOPE_OFFSET

The header keyword for the RA telescope offset changed from RAOFF to TRAOFF on 20050315, so return the proper keyword depending on observation date.

to_DETECTOR_READ_TYPE

Should be the "MODE" header but if this is missing we can look at INTTYPE instead.

to_SAMPLING

Converts FITS header values in DETINCR and DETNINCR to a single descriptive string.

from_TELESCOPE

Returns 'UKIRT, Mauna Kea, HI' for the TELESCOP FITS header.

SEE ALSO

Astro::FITS::HdrTrans, Astro::FITS::HdrTrans::UKIRT.

AUTHOR

Brad Cavanagh <b.cavanagh@jach.hawaii.edu>, Tim Jenness <t.jenness@jach.hawaii.edu>.

COPYRIGHT

Copyright (C) 2003-2005 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