Separation of multiple secondary surveillance radar sources in a real environment for the near-far case

Multilateration systems based on Secondary Surveillance Radar (SSR) systems and omni-directional antennae are operational today [1,2]. Assuming the replacement of the single-element antenna by an array, we proposed new algorithms to discriminate overlapped signals in previous works [3,4,5]; other solutions were also proposed in the literature [6,7,8]. Unfortunately, all have either some shortcomings, or an expensive computational cost, or no simple practical implementation. Therefore, we proposed in [9] a reliable, simple, and effective projection algorithm. Nevertheless, some issues were overlooked: in particular the relative power ratio between the signals to be separated may be important, which we study in this paper with real-life signals.