view release on metacpan or  search on metacpan

eg/xml  view on Meta::CPAN

    qw{ latitude=f longitude=f height=f horizon=f twilight=f more+
    time_zone|time-zone|zone=s pretty! },
    help => sub { pod2usage( { -verbose => 2 } ) },
) or pod2usage( { -verbose => 0 } );

my $now = time;		# The time the script was run.
my $start_time;		# The start time for the prediction
if ( my $time = shift @ARGV ) {
    require Date::Manip;
    $start_time = Date::Manip::UnixDate( $time, '%s' )
	or die "Invalid start time $time\n";
} else {
    $start_time = $now;
}
my $days = shift @ARGV || 7;	# Number of days to predict

# Retrieve the TLE data from Celestrak.

my $getter = Astro::SpaceTrack->new( direct => 1, with_name => 1 );
my $resp = $getter->celestrak( 'stations' );
$resp->is_success()
    or die 'Failed to retrieve TLE data: ', $resp->status_line();

# Parse the TLE data, eliminating any Progress or Soyuz modules, or
# whatever else may be in the same data set.

my ( $iss ) = grep { 25544 == $_->get( 'id' ) }
    Astro::Coord::ECI::TLE->parse( $resp->content() );

# Set up our location

my $sta = Astro::Coord::ECI->new(
)->geodetic(
    deg2rad( $opt{latitude} ),
    deg2rad( $opt{longitude} ),
    $opt{height} / 1000,
);

# Configure the TLE object as desired for the pass prediction, based on
# the option values.

$iss->set(
    horizon	=> deg2rad( $opt{horizon} ),
    pass_variant => ( $opt{more} ?
	PASS_VARIANT_NONE :
	PASS_VARIANT_VISIBLE_EVENTS | PASS_VARIANT_FAKE_MAX |
	    PASS_VARIANT_START_END
    ),
    station	=> $sta,
    twilight	=> deg2rad( $opt{twilight} ),
    visible	=> $opt{more} < 2,
);

# Compute the passes.

my @passes = $iss->pass( $start_time, $start_time + $days * 86400 );

# Put the output into UTF-8 mode, since that is what we intend to use.
# This gets eval'ed to hide it if we're using Perl 5.6.

$] ge '5.008'
    and eval "binmode STDOUT, ':encoding(utf-8)'";

# Now fire up the XML generator.

my $xw = XML::Writer->new(
    DATA_MODE	=> $opt{pretty},
    DATA_INDENT => 4,
    ENCODING	=> 'utf-8',
);

# Start the XML.

$xw->xmlDecl();	# The declaration
$xw->startTag( 'transits',	# The document tag
    latitude => $opt{latitude},
    longitude => $opt{longitude},
    altitude => $opt{height},
    timezone => $opt{time_zone},
    days => $days,
    gmtnow => DateTime->from_epoch(
	epoch => $now,
	time_zone => 'GMT',
    )->strftime( '%Y-%m-%dT%H:%M:%S' ),
    object => $iss->get( 'name' ),
    oid => $iss->get( 'id' ),
);

# For each pass,

my $pass_number = 1;
foreach my $pass ( @passes ) {

    # Emit the start tag for the pass

    $xw->startTag( 'pass',
	number => $pass_number++,
	date => DateTime->from_epoch(
	    epoch => $pass->{events}[0]{time},
	    time_zone => $opt{time_zone},
	)->strftime( '%Y-%m-%d' ),
    );

    # For each event in the pass

    foreach my $event ( @{ $pass->{events} } ) {

	# Emit a tag representing the event itself

	$xw->startTag( $event->{event} );

	# Emit the time of the event

	$xw->dataElement( time => DateTime->from_epoch(
		epoch => $event->{time},
		time_zone => $opt{time_zone},
	    )->strftime( '%H:%M:%S' ),
	);

	# Emit the elevation of the event