summaryrefslogtreecommitdiffstats
path: root/org/madore/ephem/Precession.java
diff options
context:
space:
mode:
authorDavid A. Madore <david+git@madore.org>2012-03-27 19:05:08 +0200
committerDavid A. Madore <david+git@madore.org>2012-03-27 19:46:09 +0200
commit221c71e37bdc19dc5bbc1f0303697f67847b7712 (patch)
tree677f3d9a07dc68146d74dad90af7832d0b81300e /org/madore/ephem/Precession.java
parentd7ffd8429e8fa68a43710f2d27c266c5c2ab670c (diff)
downloadephem-221c71e37bdc19dc5bbc1f0303697f67847b7712.tar.gz
ephem-221c71e37bdc19dc5bbc1f0303697f67847b7712.tar.bz2
ephem-221c71e37bdc19dc5bbc1f0303697f67847b7712.zip
Nutation.
Diffstat (limited to 'org/madore/ephem/Precession.java')
-rw-r--r--org/madore/ephem/Precession.java8
1 files changed, 5 insertions, 3 deletions
diff --git a/org/madore/ephem/Precession.java b/org/madore/ephem/Precession.java
index 5ac3a03..b52a1c5 100644
--- a/org/madore/ephem/Precession.java
+++ b/org/madore/ephem/Precession.java
@@ -3,16 +3,18 @@ package org.madore.ephem;
public final class Precession {
// The following angles are in arcseconds, argument is in Julian centuries since J2000.
- public static final double epsilon = 84381.406;
+ public static final double epsilon0 = 84381.406;
public static Comput.Polynomial psi
= new Comput.Polynomial(0, 5038.481507, -1.0790069, -0.00114045, 0.000132851, -0.0000000951);
public static Comput.Polynomial omega
- = new Comput.Polynomial(epsilon, -0.025754, 0.0512623, -0.00772503, -0.000000467, 0.0000003337);
+ = new Comput.Polynomial(epsilon0, -0.025754, 0.0512623, -0.00772503, -0.000000467, 0.0000003337);
public static Comput.Polynomial chi
= new Comput.Polynomial(0, 10.556403, -2.3814292, -0.00121197, 0.000170663, -0.0000000560);
+ public static Comput.Polynomial epsilon
+ = new Comput.Polynomial(epsilon0, -46.836769, -0.0001831, 0.00200340, -0.000000576, -0.0000000434);
public static Frames.RotationMatrix matrix(double t) {
- Frames.RotationMatrix mat1 = Frames.RotationMatrix.rotx(epsilon*Comput.arcsecond);
+ Frames.RotationMatrix mat1 = Frames.RotationMatrix.rotx(epsilon0*Comput.arcsecond);
Frames.RotationMatrix mat2 = Frames.RotationMatrix.rotz(-psi.v(t)*Comput.arcsecond).apply(mat1);
Frames.RotationMatrix mat3 = Frames.RotationMatrix.rotx(-omega.v(t)*Comput.arcsecond).apply(mat2);
Frames.RotationMatrix mat4 = Frames.RotationMatrix.rotz(chi.v(t)*Comput.arcsecond).apply(mat3);