Improve estimation of propagation and measurement parameters with Unscented Kalman Filter
Currently the Unscented Kalman Filter can "estimate" propagation and measurement parameters without throwing any exception. However, because these parameters are not “time propagated” like orbital parameters, the propagated sigma points are equals to the initial sigma points for these parameters. As a results, they don’t have any evolution because the computation of the corrected value depends on the difference between the propagated and the initial ones.
A solution is presented in the following paper:
Matthew C. VANDYKE et al. Unscented Kalman Filtering for Spacecraft attitude state and parameter estimation. AAS.
Probably the fix will also need modifications in Hipparchus.