I would love to have a higher level abstraction for receiver, encompassing both ground stations ans spaceborne receivers, this would reduce code duplication significantly and would be easier to understand.
One thing that may be tricky is the fact that for spaceborne receivers, the receiver is often the thing we want to estimate, but sometimes it is the other way round, and sometimes both link ends have to be estimated. We already have the possibility to estimate the receiver position for ground stations (slightly adjusting it be estimating some Cartesian offsets), but it is clumsy.
We need to design a better architecture.