Loading normalized spherical harmonics for the moon

Orekit usage
5

Hi Frank,

The GL0660B model (http://icgem.gfz-potsdam.de/getmodel/gfc/b4f8182e0e0a2112fc3720a2fb5d10f885e4aed39652b8ba8e9d3c2a8645c29c/GL0660B.gfc) I have been using does have sigma C and sigma S columns, so 7 columns in total.

The following piece of code works for me for instance:

GravityFieldFactory.clearPotentialCoefficientsReaders();
ICGEMFormatReader potentialCoefficientsReader = new ICGEMFormatReader("GL0660B.gfc", false);
GravityFieldFactory.addPotentialCoefficientsReader(potentialCoefficientsReader);
NormalizedSphericalHarmonicsProvider moonHarmonicsProvider = GravityFieldFactory.getNormalizedProvider(64, 64);
ForceModel moonForceModel = new HolmesFeatherstoneAttractionModel(
                CelestialBodyFactory.getMoon().getInertiallyOrientedFrame(), moonHarmonicsProvider);

Cheers
Clément