package Astro::FITS::HdrTrans::GEMINI;
=head1 NAME
Astro::FITS::HdrTrans::GEMINI - Base class for translation of Gemini instruments
=head1 SYNOPSIS
use Astro::FITS::HdrTrans::GEMINI;
=head1 DESCRIPTION
This class provides a generic set of translations that are common to
instrumentation from the Gemini Observatory. It should not be used
directly for translation of instrument FITS headers.
=cut
use 5.006;
use warnings;
use strict;
use Carp;
# Inherit from the Base translation class and not HdrTrans itself
# (which is just a class-less wrapper).
use base qw/ Astro::FITS::HdrTrans::FITS /;
use Scalar::Util qw/ looks_like_number /;
use Astro::FITS::HdrTrans::FITS;
use vars qw/ $VERSION /;
$VERSION = "1.50";
# in each class we have three sets of data.
# - constant mappings
# - unit mappings
# - complex mappings
# for a constant mapping, there is no FITS header, just a generic
# header that is constant
my %CONST_MAP = (
);
# unit mapping implies that the value propogates directly
# to the output with only a keyword name change
my %UNIT_MAP = (
AIRMASS_END => "AMEND",
AIRMASS_START => "AMSTART",
DEC_BASE => "CRVAL2",
EXPOSURE_TIME => "EXPTIME",
EQUINOX => "EQUINOX",
INSTRUMENT => "INSTRUME",
NUMBER_OF_EXPOSURES => "NSUBEXP",
NUMBER_OF_EXPOSURES => "COADDS",
OBJECT => "OBJECT",
X_REFERENCE_PIXEL => "CRPIX1",
Y_REFERENCE_PIXEL => "CRPIX2"
);
# Create the translation methods
__PACKAGE__->_generate_lookup_methods( \%CONST_MAP, \%UNIT_MAP );
=head1 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)
=over 4
=cut
# Note use list context as there are multiple CD matrices in
# the header. We want scalar context.
sub to_DEC_SCALE {
my $self = shift;
my $FITS_headers = shift;
my $cd11 = $FITS_headers->{"CD1_1"};
my $cd12 = $FITS_headers->{"CD1_2"};
my $cd21 = $FITS_headers->{"CD2_1"};
my $cd22 = $FITS_headers->{"CD2_2"};
my $sgn;
if ( ( $cd11 * $cd22 - $cd12 * $cd21 ) < 0 ) {
$sgn = -1;
} else {
$sgn = 1;
}
abs( sqrt( $cd11**2 + $cd21**2 ) );
}
sub to_DEC_TELESCOPE_OFFSET {
my $self = shift;
my $FITS_headers = shift;
# It's simple when there's a header.
my $offset = $FITS_headers->{ "DECOFFSE" };
# Otherwise for older data have to derive an offset from the source
# position and the frame position. This does assume that the
# reference pixel is unchanged in the group. The other headers
# are measured in degrees, but the offsets are in arceseconds.
if ( !defined( $offset ) ) {
my $decbase = $FITS_headers->{ "CRVAL2" } ;
my $dec = $FITS_headers->{ "DEC" };
if ( defined( $decbase ) && defined( $dec ) ) {
$offset = 3600.0 * ( $dec - $decbase );
} else {
$offset = 0.0;
}
}
return $offset;
}
sub from_DEC_TELESCOPE_OFFSET {
my $self = shift;
my $generic_headers = shift;
"DECOFFSE", $generic_headers->{ "DEC_TELESCOPE_OFFSET" };
}
sub to_FILTER {
my $self = shift;
my $FITS_headers = shift;
my $filter = "";
my $filter1 = $FITS_headers->{ "FILTER1" };
my $filter2 = $FITS_headers->{ "FILTER2" };
my $filter3 = $FITS_headers->{ "FILTER3" };
if ( $filter1 =~ "open" ) {
$filter = $filter2;
}
if ( $filter2 =~ "open" ) {
$filter = $filter1;
}
if ( ( $filter1 =~ "blank" ) ||
( $filter2 =~ "blank" ) ||
( $filter3 =~ "blank" ) ) {
$filter = "blank";
}
return $filter;
}
sub to_OBSERVATION_TYPE {
my $self = shift;
my $FITS_headers = shift;
my $type = $FITS_headers->{ "OBSTYPE" };
if ( $type eq "SCI" || $type eq "OBJECT-OBS" ) {
$type = "OBJECT";
}
return $type;
}
sub to_RA_BASE {
my $self = shift;
my $FITS_headers = shift;
my $ra = 0.0;
if ( exists ( $FITS_headers->{CRVAL1} ) ) {
$ra = $FITS_headers->{CRVAL1};
}
$ra = defined( $ra ) ? $ra: 0.0;
return $ra;
}
sub to_RA_SCALE {
my $self = shift;
my $FITS_headers = shift;
my $cd12 = $FITS_headers->{"CD1_2"};
my $cd22 = $FITS_headers->{"CD2_2"};
sqrt( $cd12**2 + $cd22**2 );
}
sub to_RA_TELESCOPE_OFFSET {
my $self = shift;
my $FITS_headers = shift;
# It's simple when there's a header.
my $offset = $FITS_headers->{ "RAOFFSET" };
# Otherwise for older data have to derive an offset from the source
# position and the frame position. This does assume that the
# reference pixel is unchanged in the group. The other headers
# are measured in degrees, but the offsets are in arceseconds.
if ( !defined( $offset ) ) {
my $rabase = $FITS_headers->{ "CRVAL1" };
my $ra = $FITS_headers->{ "RA" };
my $dec = $FITS_headers->{ "DEC" };
if ( defined( $rabase ) && defined( $ra ) && defined( $dec ) ) {
$offset = 3600* ( $ra - $rabase ) * cosdeg( $dec );
} else {
$offset = 0.0;
}
}
return $offset;
}
sub from_RA_TELESCOPE_OFFSET {
my $self = shift;
my $generic_headers = shift;
"RAOFFSE", $generic_headers->{ "RA_TELESCOPE_OFFSET" };
}
sub to_UTSTART {
my $self = shift;
my $FITS_headers = shift;
my $return;
if (exists $FITS_headers->{'DATE-OBS'}) {
my $iso;
if ( $FITS_headers->{'DATE-OBS'} =~ /T/ ) {
# standard format
$iso = $FITS_headers->{'DATE-OBS'};
} elsif ( exists $FITS_headers->{UTSTART} ) {
$iso = $FITS_headers->{'DATE-OBS'}. "T" . $FITS_headers->{UTSTART};
} elsif ( exists $FITS_headers->{UT} ) {
$iso = $FITS_headers->{'DATE-OBS'}. "T" . $FITS_headers->{UT};
}
$return = $self->_parse_iso_date( $iso ) if $iso;
}
return $return;
}
sub to_UTEND {
my $self = shift;
my $FITS_headers = shift;
my $return;
if ( exists $FITS_headers->{'DATE-END'} ) {
$return = $self->_parse_iso_date( $FITS_headers->{'DATE-END'} );
} elsif (exists $FITS_headers->{'DATE-OBS'}) {
my $iso;
my $ut;
if ( $FITS_headers->{'DATE-OBS'} =~ /T/ ) {
$ut = $FITS_headers->{'DATE-OBS'};
$ut =~ s/T.*$//;
} else {
$ut = $FITS_headers->{'DATE-OBS'};
}
if (exists $FITS_headers->{UTEND}) {
$iso = $ut. "T" . $FITS_headers->{UTEND};
}
$return = $self->_parse_iso_date( $iso ) if $iso;
}
return $return;
}
sub to_UTDATE {
my $self = shift;
my $FITS_headers = shift;
return $self->get_UT_date( $FITS_headers );
}
sub from_UTEND {
my $self = shift;
my $generic_headers = shift;
my $utend = $generic_headers->{UTEND}->strptime( '%T' );
return ( "UTEND"=> $utend );
}
sub from_UTSTART {
my $self = shift;
my $generic_headers = shift;
my $utstart = $generic_headers->{UTSTART}->strptime('%T');
return ( "UTSTART"=> $utstart );
}
sub from_UTDATE {
my $self = shift;
my $generic_headers = shift;
my $ymd = $generic_headers->{UTDATE};
my $dobs = substr( $ymd, 0, 4 ) . "-" . substr( $ymd, 4, 2 ) ."-" . substr( $ymd, 6, 2 );
return ( "DATE-OBS"=>$dobs );
}
# Supplementary methods for the translations
# ------------------------------------------
# Returns the UT date in YYYYMMDD format.
sub get_UT_date {
my $self = shift;
my $FITS_headers = shift;
# This is UT start and time.
my $dateobs = $FITS_headers->{"DATE-OBS"};
# Extract out the data in yyyymmdd format.
return substr( $dateobs, 0, 4 ) . substr( $dateobs, 5, 2 ) . substr( $dateobs, 8, 2 );
}
=back
=head1 REVISION
$Id: ESO.pm 14385 2007-08-27 22:01:06Z timj $
=head1 SEE ALSO
C<Astro::FITS::HdrTrans>, C<Astro::FITS::HdrTrans::Base>.
=head1 AUTHOR
Paul Hirst <p.hirst@jach.hawaii.edu>
Malcolm J. Currie <mjc@star.rl.ac.uk>
Tim Jenness E<lt>t.jenness@jach.hawaii.eduE<gt>
=head1 COPYRIGHT
Copyright (C) 2007-2008 Science and Technology Facilities Council.
Copyright (C) 2006-2007 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.
=cut
1;