Analysis of SSR signals by super resolution algorithms

A new method for SSR (secondary surveillance radar) signal analysis, in particular SSR Mode S replies, can be obtained exploiting the super resolution algorithms capability to discriminate signals in the frequency domain. This work summarises the results obtained by the application of Tufts-Kumaresan, Music, Esprit and Unitary Esprit algorithms to decode Mode S replies and squitters acquired in a live environment. Hence, we propose 16 possible processing schemes which, compared to conventional schemes, have shown sensible improvements. It results that the main limit is represented by the quality of the on board transponder local oscillator which causes a too small spectral separation between two overlapped signals.