Passive Monostatic Radar with Deterministic Multifrequency Dither for Single-Dwell Multi-Target Localization

Abstract

This correspondence extends a previously introduced waveform-domain monostatic passive radar from single-target localization to simultaneous multi-target detection and localization. The radar employs a Sparse Uniform Circular Array (SUCA) with Deterministic Multifrequency Dither (DMD), for which target location is represented by a precomputed physical waveform dictionary. The previously developed QR formulation transforms the dictionary and the received composite waveform into an orthogonal Q-space, where correlations provide direct detection and physical-index localization without conventional range–Doppler processing. Two complementary performance measures are considered. First, target-presence detection is evaluated at a prescribed false-alarm probability of Pfa=10−4. Monte Carlo results show high detection probability with only weak dependence on the number of simultaneously present targets for P=1,…,10. Second, exact complete-index recovery is used to quantify multi-target localization. For both range-separated and azimuth-separated targets, the exact-recovery probability approaches unity for all investigated target populations P=1,…,10, with substantially lower SNR required in the azimuth-separated case. These results are obtained from a single T = 1 μs dwell without Doppler separation, temporal averaging, tracking, sequential target cancellation, or explicit estimation of the unknown scattering coefficients. The results demonstrate the feasibility of extending waveform-domain passive sensing to simultaneous multi-target detection and direct physical-index localization using narrowband signals of opportunity.