my $l;
my $n_offset;
my @list;
+my ($rise, $set, $az, $dec, $loss, $ifrac);
while ($f = shift @f){
if(!$n_offset){
}
foreach $l (@in) {
- my ($rise, $set, $az, $dec, $loss )=Sun::rise_set($yr,$month,$day,$hr,$min,$l->[1],$l->[2],1);
+ ($rise, $set, $az, $dec, $loss, $ifrac)=Sun::rise_set($yr,$month,$day,$hr,$min,$l->[1],$l->[2],1);
$l->[3] =~ s{(-\d+|/\w+)$}{};
if( !$n_offset ) {
push @out,sprintf("%-6.6s %-30.30s %02d/%02d/%4d %s %s %6.1f %6.1f", $l->[3], $l->[0], $day, $month, $yr, $rise, $set, $az, $dec);
push @out,sprintf("%-6.6s %-30.30s %02d/%02d/%4d %s %s", $l->[3], $l->[0], $day, $month, $yr, $rise, $set);
}
}
-
-
-
+push @out,sprintf("Illuminated fraction of the Moon's disk is %4.2f",$ifrac);
return (1, @out);
-#!/usr/bin/perl -w
+#/usr/bin/perl -w
#
# This module was written by Steve Franke K9AN.
# November, 1999.
my ($alpha1,$alpha2,$alpha3,$delta1,$delta2,$delta3);
my ($m0,$m1,$m2,$theta,$alpha,$delta,$H,$az,$h,$h0,$aznow,$hnow,$corr);
my ($i,$arg,$argtest,$H0,$alphanow,$deltanow,$distance,$distancenow);
+ my ($ifrac,$ifracnow);
my $julianday=Julian_Day($year,$month,$day);
my $tt1 = ($julianday-1-2451545)/36525.;
}
if ( $sun0_moon1 == 1 ) {
- ($alpha1, $delta1, $distance)=get_moon_alpha_delta($tt1);
- ($alpha2, $delta2, $distance)=get_moon_alpha_delta($tt2);
- ($alpha3, $delta3, $distance)=get_moon_alpha_delta($tt3);
- ($alphanow, $deltanow, $distancenow)=get_moon_alpha_delta($ttnow);
+ ($alpha1, $delta1, $distance, $ifrac)=get_moon_alpha_delta($tt1);
+ ($alpha2, $delta2, $distance, $ifrac)=get_moon_alpha_delta($tt2);
+ ($alpha3, $delta3, $distance, $ifrac)=get_moon_alpha_delta($tt3);
+ ($alphanow, $deltanow, $distancenow, $ifracnow)=get_moon_alpha_delta($ttnow);
$h0=0.7275*$r2d*asin(6378.14/$distancenow)-34./60.;
$H=$thetanow-$lon-$alphanow;
$H=reduce_angle_to_360($H);
}
if ( $sun0_moon1 == 1 ) {
return (sprintf("%s", $risetime), sprintf("%s",$settime),
- $aznow+180,$hnow, -40*log10($distance/385000) );
+ $aznow+180,$hnow, -40*log10($distance/385000), $ifracnow );
}
}
sub get_moon_alpha_delta
#
# Calculate the moon's right ascension and declination
#
+ # As of October 2001, also calculate the illuminated fraction of the
+ # moon's disk... (why not?)
+ #
my $tt=shift;
my $Lp=218.3164477+481267.88123421*$tt-
my $delta=asin(cosdeg($beta)*sindeg($epsilon)*sindeg($lambda)+sindeg($beta)*cosdeg($epsilon))*$r2d;
$delta = reduce_angle_to_360($delta);
- return ($alpha,$delta,$distance);
+# $phase will be the "moon phase angle" from p. 346 of Meeus' book...
+ my $phase=180.0 - $D - 6.289 *sindeg($Mp)
+ + 2.100 *sindeg($M)
+ - 1.274 *sindeg(2.*$D - $Mp)
+ - 0.658 *sindeg(2.*$D)
+ - 0.214 *sindeg(2.*$Mp)
+ - 0.110 *sindeg($D);
+
+# $illum_frac is the fraction of the disk that is illuminated, and will be
+# zero at new moon and 1.0 at full moon.
+
+ my $illum_frac = (1.0 + cosdeg( $phase ))/2.;
+
+ return ($alpha,$delta,$distance,$illum_frac);
}
sub get_sun_alpha_delta