Orekit v10.0 EclipseDetector setting the OneAxisEllipsoid Frame for non-Earth bodies

Dear Orekit Team,

First of all thanks for the great work in delivering the v10.0!

I have updated my project to this version, and I would like to ask you how to configure the EclipseDetector, since I have seen that now it makes use of the OneAxisEllipsoid.
In particular on how to define the Frame of the OneAxisEllipsoid if I want to take other bodies into account instead of the Earth.

Thank you for your answer

Kind Regards

Hi Leonardo,

The OneAxisEllipsoid parameter allows the eclipse detector to take into account the flatness of the eclipsing body. This is related to the Z axis of the body frame you specify.

If your eclipsing body is one of the CelestialBody available in Orekit (say Mars or Jupiter), then you can just call thebody.getBodyOrientedFrame() which will return the official reference frame defined by the IAU/IAG Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites (WGCCRE).

If your eclipsing body is not one of the bodies provided by Orekit, you need to creae its frame by yourself. The important part there will be to have this frame centered at the ellipsoid center and the Z axis aligned with the polar axis of the ellipsoid. The rotation around the Z axis (i.e. the directions of X and Y axes) is not important in this case because the ellipsoid has a rotational symmetry.

Hi Luc,

thank you really much for your fast answer :slight_smile: