Broadband target detection algorithm in FM‐based passive bistatic radar systems

Abstract

In this study, the authors propose a new broadband target detection algorithm for FM-based passive bistatic radar systems, which simultaneously exploits multiple FM radio channels transmitted by the same transmitting station. It is shown that the joint exploitation of the signals of opportunity received at multiple carrier frequencies improves target detection capability as well as the target range resolution. In addition, the proposed detection algorithm exploits all available information making the detection performance robust against time-varying program content broadcast by the individual FM radio channels. Therefore, after formulating the broadband target detection problem as a composite hypothesis test, they derive a broadband uniformly most powerful invariant (B-UMPI) test, together with a closed-form expression for a statistical threshold that allows for automatic detection. To get a better insight into the detection performance of the proposed detector, a close-form expression for the probability of detection is also derived. In addition, they analytically show that how the range resolution of the proposed broadband target detection algorithm improves. They also analytically obtain an integrated sidelobe level ratio at the output of the B-UMPI statistics to show an improvement in the target detection quality. Finally, they provide some simulation examples to validate the authors’ theoretical analysis as well as to show the improvement in the target detection capability and the target range resolution in the broadband FM-based passive bistatic radar systems.