Exploiting long coherent integration times in DVB-T based passive radar systems

Long coherent integration times can be exploited in passive radar systems in order to broaden their coverage and to improve their target detection capability. However, proper strategies must be considered to compensate for the target migration effects that could limit the system performance when long coherent processing intervals are used. In this paper, we refer to the case of a passive coherent location system for air traffic surveillance, exploiting DVB-T signals as source of opportunity, and we propose two strategies able to deal with the typically high speeds and possible accelerations of civil aircrafts. We show that the proposed detection schemes allow to effectively correct the target walk effects and therefore to benefit from the extended coherent integration time, while controlling the false alarm rate. The effectiveness is demonstrated on both simulated and real data provided by Leonardo S.p.A. The experimental results clearly show that the proposed approaches allow the coherent integration time to be increased up to a few seconds.