view release on metacpan or  search on metacpan

lib/Astro/Catalog/Query/USNOA2.pm  view on Meta::CPAN

package Astro::Catalog::Query::USNOA2;

=head1 NAME

Astro::Catalog::Query::USNOA2 - A query request to the USNO-A2.0 Catalog

=head1 SYNOPSIS

    $usno = new Astro::Catalog::Query::USNOA2(
            Coords    => new Astro::Coords(),
            Radius    => $radius,
            Bright    => $magbright,
            Faint     => $magfaint,
            Sort      => $sort_type,
            Number    => $number_out);

    my $catalog = $usno->querydb();

=head1 DESCRIPTION

The module is an object orientated interface to the online USNO-A2.0
catalog at the ESO/ST-ECF archive site.

Stores information about an prospective USNO-A2.0 query and allows the query to
be made, returning an Astro::Catalog::USNOA2::Catalog object.

The object will by default pick up the proxy information from the HTTP_PROXY
and NO_PROXY environment variables, see the LWP::UserAgent documentation for
details.

See L<Astro::Catalog::BaseQuery> for the catalog-independent methods.

=cut

use strict;
use warnings;
use base qw/Astro::Catalog::Transport::REST/;

use File::Spec;
use Carp;

use Astro::Coords;
use Astro::Catalog;
use Astro::Catalog::Item;

use Astro::Flux;
use Astro::Fluxes;
use Astro::FluxColor;
use Number::Uncertainty;

our $VERSION = '4.38';

=begin __PRIVATE_METHODS__

=head2 Private methods

These methods are for internal use only.

=over 4

=item B<_default_remote_host>

=cut

sub _default_remote_host {
    return "archive.eso.org";
}

=item B<_default_url_path>

=cut

sub _default_url_path {
    return "skycat/servers/usnoa_res?";
}

=item B<_get_allowed_options>

Returns a hash with keys, being the internal options supported
by this subclass, and values being the key name actually required
by the remote system (and to be included in the query).

=cut

sub _get_allowed_options {
    my $self = shift;
    return (
        ra => 'ra',
        dec => 'dec',
        object => 'object',
        radmax => 'radmax',
        magbright => 'magbright',
        magfaint => 'magfaint',
        sort => 'sort',
        nout => 'nout',
        format => 'format',
   );
}

=item B<_get_default_options>

Get the default query state.

=cut

sub _get_default_options {
    return (
        ra => undef,
        dec => undef,

lib/Astro/Catalog/Query/USNOA2.pm  view on Meta::CPAN

                                    name => $star->id(),
                                ));
                    }

                    # Quality
                    my $quality = $separated[10];
                    $star->quality( $quality );

                    # Field
                    my $field = $separated[11];
                    $star->field( $field );

                    # GSC
                    my $gsc = $separated[12];
                    if ($gsc eq "+") {
                        $star->gsc("TRUE");
                    }
                    else {
                        $star->gsc("FALSE");
                    }

                    # Distance
                    my $distance = $separated[13];
                    $star->distance( $distance );

                    # Position Angle
                    my $pos_angle = $separated[14];
                    $star->posangle( $pos_angle );
                }

                # Calculate error

                # Error are calculated as follows
                #
                #   Delta.R = 0.15*sqrt( 1 + 10**(0.8*(R-19)) )
                #   Delta.B = 0.15*sqrt( 1 + 10**(0.8*(B-19)) )
                my ($power, $delta_r, $delta_b);

                # delta.R
                $power = 0.8*( $separated[8] - 19.0 );
                $delta_r = 0.15* (( 1.0 + ( 10.0 ** $power ) ) ** (1.0/2.0));

                # delta.B
                $power = 0.8*( $separated[9] - 19.0 );
                $delta_b = 0.15* (( 1.0 + ( 10.0 ** $power ) ) ** (1.0/2.0));


                # calcuate B-R colour and error

                # Error is calculated as follows
                #
                #   Delta.(B-R) = sqrt( Delta.R**2 + Delta.B**2 )

                my $b_minus_r = $separated[9] - $separated[8];

                # delta.(B-R)
                my $delta_bmr = ( ( $delta_r ** 2.0 ) + ( $delta_b ** 2.0 ) ) ** (1.0/2.0);

                $star->fluxes(new Astro::Fluxes(
                            new Astro::Flux(
                                new Number::Uncertainty(
                                    Value => $separated[8],
                                    Error => $delta_r ),
                                'mag', "R"),
                            new Astro::Flux(
                                new Number::Uncertainty(
                                    Value => $separated[9],
                                    Error => $delta_b),
                                'mag', "B"),
                            new Astro::FluxColor(
                                lower => "R",
                                upper => "B",
                                quantity => new Number::Uncertainty(
                                    Value => $b_minus_r,
                                    Error => $delta_bmr)),
                        ));

                # Push the star into the catalog

                # only push the star if the Astro::Coords object is
                # correctly defined. The Dec might be bogus since the
                # USNO-A2 catalog has its seconds field out of
                # normal range (0-59.9) in some cases.
                if ($star->coords()) {
                    $catalog->pushstar($star);
                }

                # increment counter
                $counter = $counter + 1;
            }

            # reset $line to correct place
            $line = $counter;
        }
    }

    # set the field centre
    $catalog->fieldcentre(%field);

    return $catalog;
}

=back

=head2 Translation Methods

The query options stored internally in the object are not necessarily
the form required for a query to a remote server. Methods for converting
from the internal representation to the external query format are
provided in the form of _from_$opt. ie:

    ($outkey, $outvalue) = $q->_from_ra();
    ($outkey, $outvalue) = $q->_from_object();

Currently translations are a bit thin on the ground...

=cut

# None special for subclass

1;

__END__

=end __PRIVATE_METHODS__

=head1 SEE ALSO

L<Astro::Catalog::Query>, L<Astro::Catalog::GSC::Query>

=head1 COPYRIGHT

Copyright (C) 2001 University of Exeter. All Rights Reserved.