Prime meridian angle

1

Hi,
I would like to evaluate the prime meridian angle at date d for a celestial body.
I tried to access to this information throw the IUAPole interface using PredefinedIAUPoles but unfortunally, this enum is not public and cannot be used.
What is the best way to access to IAU pole and prime meridian orientations information in Orekit ?

Regards,
Guillaume

2

You could try to get the two body-related frames, using getInertiallyOrientedFrame and getBodyOrientedFrame. Then something along these lines should work:

  Transform bodyToInert = bodyOriented.getTransformTo(inertiallyOriented, date);
  Vector3D meridianInInertial = bodyToInert.transformVector(Vector3D.PLUS_I);
  double alpha = meridianInInertial.getAlpha();