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lib/Astro/FITS/HdrTrans/JCMT.pm  view on Meta::CPAN

our $VERSION = '1.66';

use base qw/ Astro::FITS::HdrTrans::JAC /;

# Unit mapping implies that the value propogates directly
# to the output with only a keyword name change.
my %UNIT_MAP =
  (
    AIRMASS_START        => 'AMSTART',
    AZIMUTH_START        => 'AZSTART',
    ELEVATION_START      => 'ELSTART',
    FILENAME             => 'FILE_ID',
    DR_RECIPE            => "RECIPE",
    HUMIDITY             => 'HUMSTART',
    LATITUDE             => 'LAT-OBS',
    LONGITUDE            => 'LONG-OBS',
    OBJECT               => 'OBJECT',
    OBSERVATION_NUMBER   => 'OBSNUM',
    PROJECT              => 'PROJECT',
    SCAN_PATTERN         => 'SCAN_PAT',
    STANDARD             => 'STANDARD',
    TAI_UTC_CORRECTION   => 'DTAI',
    UT1_UTC_CORRECTION   => 'DUT1',
    WIND_BLIND           => 'WND_BLND',
    X_APERTURE           => 'INSTAP_X',
    Y_APERTURE           => 'INSTAP_Y',
  );

my %CONST_MAP = ();

# Create the translation methods
__PACKAGE__->_generate_lookup_methods( \%CONST_MAP, \%UNIT_MAP );

our $COORDS;

=head1 METHODS

=over 4

=item B<translate_from_FITS>

This routine overrides the base class implementation to enable the
caches to be cleared for target location.

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.

Date fixups are handled in a super class.

=cut

sub translate_from_FITS {
  my $class = shift;
  my $headers = shift;

  # clear cache
  $COORDS = undef;

  # Go to the base class
  return $class->SUPER::translate_from_FITS( $headers, @_ );
}

=item B<to_UTDATE>

Converts the date in a date-obs header into a number of form YYYYMMDD.

=cut

sub to_UTDATE {
  my $class = shift;
  my $FITS_headers = shift;

  $class->_fix_dates( $FITS_headers );
  return $class->SUPER::to_UTDATE( $FITS_headers, @_ );
}

=item B<to_UTEND>

Converts UT date in a date-end header into C<Time::Piece> object

=cut

sub to_UTEND {
  my $class = shift;
  my $FITS_headers = shift;

  $class->_fix_dates( $FITS_headers );
  return $class->SUPER::to_UTEND( $FITS_headers, @_ );
}

=item B<to_UTSTART>

Converts UT date in a date-obs header into C<Time::Piece> object.

=cut

sub to_UTSTART {
  my $class = shift;
  my $FITS_headers = shift;

  $class->_fix_dates( $FITS_headers );
  return $class->SUPER::to_UTSTART( $FITS_headers, @_ );
}

=item B<to_RA_BASE>

Uses the elevation, azimuth, telescope name, and observation start
time headers (ELSTART, AZSTART, TELESCOP, and DATE-OBS headers,
respectively) to calculate the base RA.

Returns the RA in degrees.

=cut

sub to_RA_BASE {
  my $self = shift;
  my $FITS_headers = shift;

  my $coords = $self->_calc_coords( $FITS_headers );
  return undef unless defined $coords;
  return $coords->ra( format => 'deg' );
}

=item B<to_DEC_BASE>

Uses the elevation, azimuth, telescope name, and observation start
time headers (ELSTART, AZSTART, TELESCOP, and DATE-OBS headers,
respectively) to calculate the base declination.

Returns the declination in degrees.

=cut

sub to_DEC_BASE {
  my $self = shift;
  my $FITS_headers = shift;

  my $coords = $self->_calc_coords( $FITS_headers );

  return undef unless defined $coords;
  return $coords->dec( format => 'deg' );
}

=item B<to_TAU>

Use the average WVM tau measurements.

=cut

sub to_TAU {
  my $self = shift;
  my $FITS_headers = shift;

  my $tau = undef;
  for my $src (qw/ TAU225 WVMTAU /) {
    my $st = $src . "ST";
    my $en = $src . "EN";

    my @startvals = $self->via_subheader_undef_check( $FITS_headers, $st );
    my @endvals   = $self->via_subheader_undef_check( $FITS_headers, $en );
    my $startval = $startvals[0];
    my $endval = $endvals[-1];