Hi everyone !
I have noticed that when using BatchLSEstimator , the propagator builder automatically get one additional force NewtonianAttraction after calling the .estimate() method. Is it not already included in the HolmesFeatherStone gravitational harmonics ?
I have read in this topic link that it should be removed for interplanetary orbit determination, but I don’t quite get the difference with LEO OD or how to perform it.
Thanks for you help !
Hi there,
The HolmesFeatherStone class does not include the zeroth degree term of the potential.
The reason why the estimator adds the NewtonianAttraction is that in Orekit at the moment the OD system assumes a (possibly perturbed) two body problem. In other words, it wants a central body so it adds one.
Cheers,
Romain.
Hi Romain, thank you for your answer.
I also have just noticed that the NewtonianAttraction is manually added to the forceModels in the NumericalPropagation tutorial, it all makes sense !