NAME

Astro::FITS::HdrTrans::WFCAM - UKIRT WFCAM translations

SYNOPSIS

use Astro::FITS::HdrTrans::WFCAM;

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

DESCRIPTION

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

METHODS

this_instrument

The name of the instrument required to match (case insensitively) against the INSTRUME/INSTRUMENT keyword to allow this class to translate the specified headers. Called by the default can_translate method.

$inst = $class->this_instrument();

Returns "WFCAM".

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_DATA_UNITS

Returns the data units. This uses the BUNIT header, with a default of "counts/exp" (unless the observations was with a ND read type between 2006-10-23 and 2006-12-20 when the default was "counts/sec").

to_DEC_SCALE

Returns the declination pixel scale in in arcseconds per pixel. For Cameras 1 and 3, it scales the CD2_1 keyword to the DEC_SCALE generic header. For Cameras 2 and 4, it scales the CD2_2 keyword instead.

from_DEC_SCALE

For Cameras 1 and 3, it scales the DEC_SCALE generic header to the CD2_1 header. For Cameras 2 and 4, it scales DEC_SCALE to the CD2_2 header. The returned units are degrees per pixel.

to_GAIN

Determines the gain entirely from camera number.

The GAIN FITS header is not used.

from_GAIN

This is a null operation. The GAIN FITS header in WFCAM data is always incorrect.

to_NUMBER_OF_OFFSETS

Return the number of offsets (jitters and micro steps).

to_RA_BASE

Returns the RABASE header converted to degrees.

to_RA_SCALE

Returns the right-ascension pixel scale in arcseconds per pixel. For Cameras 1 and 3, it scales the CD1_2 keyword to the RA_SCALE generic header. For Cameras 2 and 4, it scales the CD1_1 keyword instead.

from_RA_SCALE

For Cameras 1 and 3, it scales the RA_SCALE generic header to the CD1_2 keyword. For Cameras 2 and 4, scales RA_SCALE to the CD1_1 keyword. Returned units are degrees per pixel.

to_ROTATION

Determines the rotation of the array in world co-ordinates.

SEE ALSO

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

AUTHOR

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

COPYRIGHT

Copyright (C) 2008 Science and Technology Facilities Council. 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.