Propagation between measurement steps in Sequential Filter

[aerow610]

In the interest of generating an ephemeris from solution state results, it would be nice to have propagation between the measurement steps reported out into the OD output. Or perhaps a method to generate an ephemeris from the results of a run.

While on the topic, it would also be nice to have a backwards-running smoothing function for said filter output. Filtered ephems are often jagged and unrealistic in their steps.

Thanks!