Doppler blind zone analysis for ground target tracking with bistatic airborne GMTI radar

This paper investigates the Doppler blind zone of bistatic transmitter and receiver configurations and its impact on the tracking of ground targets based on measurements from airborne ground moving target indication (GMTI) radar. The Doppler blind zone arises from the clutter cancellation by space-time adaptive processing (STAP). In general, this poses a significant challenge in ground target tracking because low-Doppler targets can easily be hidden within this blind zone, leading to sequences of missed detections that strongly deteriorate the performance of a standard tracking filter. In this study the width of the bistatic Doppler blind zone is calculated and this knowledge is incorporated into a UKF-MHT tracking algorithm. Based on simulation scenarios, it is demonstrated that in contrast to a monostatic configuration with sideways-looking radar, the minimum detectable velocity that characterizes the width of the Doppler blind zone does not need to be constant. Track results reveal the benefit of exploiting this additional knowledge.