Radio Science Subsystem - Function of The RSS

Function of The RSS

The RSS uses radio signals to probe a medium such as a planetary atmosphere. The spacecraft transmits a highly stable signal to ground stations, receives such a signal from ground stations, or both. Since the transmitted signal parameters are accurately known to the receiver, any changes to these parameters are attributable to the propagation medium or to the relative motion of the spacecraft and ground station.

The RSS is usually not a separate instrument; its functions are usually "piggybacked" on the existing telecommunications subsystem. More advanced systems use multiple antennas with orthogonal polarizations.