LXI in satellite system testing

Satellites are used for a wide range of military and aerospace applications including weather prediction, navigation, and communications. The performance of satellite systems crucially depends on achieving constant magnitude and linear phase versus frequency of the transmission coefficient within the useful band. Measuring the phase linearity and the group delay of such a system is vital. Test engineers must find a reliable way to measure group delay where the transmitters and receivers are geographically separated from one another, as well as from their controller, by significant distances.