Exploiting polarimetric diversity to mitigate the effect of interferences in FM-based passive radar

In this paper the effect of interfering sources is characterized on the performance of a passive bistatic radar exploiting a FM radio broadcast transmitter. The signals emitted on same/adjacent frequency channels by other potential transmitters located in the surveillance area are shown to significantly affect the performance of the considered system in terms of both disturbance cancellation and target detection capability. To mitigate the effect of such interferences, the exploitation of different polarizations is considered for the surveillance antenna. A preliminary approach is proposed to jointly exploit the diversity of information conveyed by different polarizations. The results are shown against a real data set collected by an experimental multi-channel passive radar prototype developed and fielded at the Infocom Dept. of the University of Rome “La Sapienza” (Italy).