Ephemeris based estimation

Hello again!

I wonder if someone could help me with some BatchLSEstimator problem.

I’m trying to perform some kind of measurements validation algorithm using the predifined tabulated orbit, so I managed to initialize Ephemeris class object for it.
But now I’m stuck. Is it possible to use Ephemeris object in BatchLSEstimator, to estimate only Measurements parameters? I mean could I solve such problem without using numerical propagation atall?


Unfortunately, not yet.
Currently, only the integration-based parpagators (i.e. numerical and DSST) can be used in
batch least square estimator (and Kalman filter). There has been successful attempts to extend
this for analytical propagator, with the work of a Thomas Paulet this summer. He implemented orbit determination for the SGP4/SDP4 analytical models.

Now we have another internship position open for continuing this work for all other analytical propagators. Ephemeris is a kind of analytical propagator, however it is a very special one as it is immutable. In your case, however, it would make sense to estimate other things rather than the orbit itself, so your case is really interesting!

Could you open an feature request on our issue tracker so we don’t forget to include this use case when we start extending Thomas’s work?

Thanks a lot, @luc! Surely I will make a request.
Wish you success! And of course, many thanks for such great tool as orekit is.