X-Git-Url: http://dxcluster.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=perl%2FSun.pm;h=0616d47321c5b57804b0e94c96745950e45b4ea1;hb=1172aa77de530206b0dbb648d8489922a518d502;hp=2fe033cd8e42911c37209f430120f402312dea98;hpb=d0adf21cbcea77d72ffc021441961039c41852bf;p=spider.git

diff --git a/perl/Sun.pm b/perl/Sun.pm
index 2fe033cd..0616d473 100644
--- a/perl/Sun.pm
+++ b/perl/Sun.pm
@@ -1,4 +1,4 @@
-#!/usr/bin/perl -w
+#/usr/bin/perl -w
 #
 # This module was written by Steve Franke K9AN. 
 # November, 1999.
@@ -18,6 +18,7 @@
 #
 # $Id$
 # 
+# 2001/12/16 Fixed Julian_Date_of_Epoch and now I actually use it...
 # 2001/09/15 some changes to take care of cases where the object 
 #            doesn't rise or set on a given day... 
 
@@ -33,7 +34,7 @@ use strict;
 
 use vars qw($VERSION $BRANCH);
 $VERSION = sprintf( "%d.%03d", q$Revision$ =~ /(\d+)\.(\d+)/ );
-$BRANCH = sprintf( "%d.%03d", q$Revision$ =~ /\d+\.\d+\.(\d+)\.(\d+)/ ) || 0;
+$BRANCH = sprintf( "%d.%03d", q$Revision$ =~ /\d+\.\d+\.(\d+)\.(\d+)/  || (0,0));
 $main::build += $VERSION;
 $main::branch += $BRANCH;
 
@@ -76,13 +77,18 @@ sub Julian_Day
 sub Julian_Date_of_Epoch
 {
 	my $epoch=shift;
-	my $year=int($epoch*1e-3);
-	$year=$year+2000 if ($year < 57);
-	$year=$year+1900 if ($year >= 57);
-	my $day=$epoch-$year*1e3;
+	my $year=int($epoch/1000);
+	my $day=$epoch-$year*1000;
+	if ($year < 57 ) {
+		$year=$year+2000;
+	}
+	else {
+		$year=$year+1900;
+	}
 	my $Julian_Date_of_Epoch=Julian_Date_of_Year($year)+$day;
 	return $Julian_Date_of_Epoch;
 }
+
 sub Julian_Date_of_Year
 {
 	my $year=shift;
@@ -169,6 +175,7 @@ sub rise_set
 	my ($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.;
@@ -198,10 +205,10 @@ sub rise_set
 	}
 
 	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);
@@ -315,7 +322,7 @@ sub rise_set
 	}
 	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 
@@ -323,6 +330,9 @@ 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-
@@ -542,7 +552,20 @@ sub get_moon_alpha_delta
 	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 
@@ -628,14 +651,7 @@ sub get_satellite_pos
 
 	my $epoch = $sat_ref ->{epoch};
 #printf("epoch = %10.2f\n",$epoch);
-	my $epoch_year=int($epoch/1000);
-	my $epoch_day=$epoch-int(1000*$epoch_year);
-#printf("epoch_year = %10.2f\n",$epoch_year);
-#printf("epoch_day = %17.12f\n",$epoch_day);
-	my $ep_year=$epoch_year+2000 if ($epoch_year < 57);
-	$ep_year=$epoch_year+1900 if ($epoch_year >= 57);
-	my $jt_epoch=Julian_Date_of_Year($ep_year);
-	$jt_epoch=$jt_epoch+$epoch_day;
+	my $jt_epoch=Julian_Date_of_Epoch($epoch);
 #printf("JT for epoch = %17.12f\n",$jt_epoch);
 	my $tsince=($jtime-$jt_epoch)*24*60;
 #printf("tsince (min) = %17.12f\n",$tsince);