[Orekit Users] Using EGM96 with DSSTPropagator

[joseph.huwaldt@dynetics.com]

I've been evaluating Orekit for use at my company.  I am very impressed.  It
appears to be very high quality software. I do have a few questions.  Here is
the first.

I want to use the EGM96 gravity model (with the WGS84 ellipsoid) in
combination with the DSSTPropagator.  But, I can't seem to get there.  It is
trivial to use the EGM96 coefficients with the EcksteinHechlerPropagator, but
I'm not seeing how to get there with the DSSTPropagator (or the
NumericalPropagator for that matter).

I see that I can use DSSTPropagator.addForceModel() to add a DSSTCentralBody
using a UnnormalizedSphericalHarmonicsProvider to supply the gravity model.
In the examples, that in turn is created using
GravityFieldFactory.getUnnormalizedProvider(degree,order).  However, that
seems to return a EIGEN-6S model.  How do I get an EGM96 model?

Any help would be appreciated.  Thanks!

Ad astra,

Joseph Huwaldt
Dynetics, Inc.
Huntsville, AL