Possible inconsistencies when using different Earth GM values within Newtonian term and the harmonics of the gravitational field

Dear all,
in order to compute the gravitational field force model (tesseral+zonal) for the DSST propagator by reading a gravitational field file (.gfc) provided within the Orekit data context, I was using:

GravityFieldFactory.getUnnormalizedProvider(degree, order)

I noticed that the central body attraction coefficient GM is taken directly from the file containing the gravity field coefficients and it is used to compute the tesseral and zonal harmonics for the DSST propagator.

However I was wondering if this could lead to inconsistencies in the computation of the gravity field if I provide a different GM for the computation of the Newtonian term when I instantiate the orbit.

In practice, I could potentially have the Newtonian term of the gravity field computed with a GM and the tesseral and zonal harmonics computed with a different GM. Or please correct me if I am mistaken.

Is this problem leading to significant errors? Do you advice to always use the GM provided within the gravity field file to instantiate the orbit if then it is used also to compute the harmonic terms of the gravity field?

Is there a way to still get the harmonic provider from the Orekit data context (as above) and set a specific GM (the same that I will provide to instantiate the orbit) also for tesseral and zonal harmonics in order to avoid inconsistencies within the computation of the gravity field force model?

Many thanks.

Best Regards.

Dear @fpan,

First of all, sorry for the delay.

You are right.

I think it is good advice and a safe way to ensure the consistency of the GM values between the force models.

I don’t think it is doable but I may be wrong.

Cheers,
Maxime