Passive Radar STAP Detection and DoA Estimation Under Antenna Calibration Errors

Abstract

This article addresses the problem of clutter cancelation for slowly moving target detection and localization in multichannel passive radar onboard mobile platforms. A post-Doppler space-time adaptive processing (STAP) approach is exploited in the case of an angle-dependent imbalance affecting the receiving channels. While the clutter suppression capability is ensured by the adaptivity of space-time filtering, different solutions are compared, aimed at recovering the detection performance losses associated with channel calibration errors. A space-time generalized-likelihood ratio test (GLRT) scheme is considered, where the steering vector is not specified in the spatial domain, resulting in a noncoherent integration of target echoes across the receiving channels. This is compared with a fully coherent GLRT scheme where echoes from the stationary scene are exploited for the proper calibration of spatial steering vector mismatch. The first scheme proves to be a simple solution for target detection in the passive radar case, offering comparable clutter cancelation capability. The Manuscript

Dual Cancelled Channel STAP for Target Detection and DOA Estimation in Passive Radar

“…Recent advances in passive radar research have opened interesting new perspectives and application areas [ 1 , 2 , 3 ]. Among them, in the last few years, the potentialities of passive radar mounted onboard moving platforms have been investigated, aiming towards synthetic aperture radar (SAR) imaging [ 4 , 5 , 6 , 7 ] and ground moving target indication (GMTI) [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ] applications.…”

“…Such limitations can be overcome by employing multiple channels on receive and applying adaptive space-time processing (STAP) techniques [ 14 , 15 , 16 , 17 , 18 ]. Specifically, a complete scheme for STAP in mobile passive radar has been recently proposed by the authors in [ 18 ].…”

“…Such limitations can be overcome by employing multiple channels on receive and applying adaptive space-time processing (STAP) techniques [ 14 , 15 , 16 , 17 , 18 ]. Specifically, a complete scheme for STAP in mobile passive radar has been recently proposed by the authors in [ 18 ]. By resorting to a post-Doppler strategy [ 21 , 22 , 23 ], it easily fits into the typical passive radar processing chain and takes advantage of the long integration times to reduce the size of the adaptive cancellation problem and compensate for potential angle-dependent channel errors.…”

“…The approach in [ 18 ] enables effective GMTI capability and gains a larger flexibility compared to the DPCA schemes thanks to the adaptive use of a higher number of spatial degrees of freedom (DOF). In fact, clutter cancellation, target detection and angular localisation, and even the spatial steering vector calibration are performed according to a fullarray strategy, i.e., by jointly exploiting all the N available channels on receive.…”

“…This technique is first integrated into the post-Doppler STAP scheme proposed in [ 18 ]. After the first processing stages are applied separately at each receiving channel, the outputs are arranged into two spatially displaced antenna sub-arrays, and a STAP scheme is applied to each of them to obtain two clutter cancelled channels.…”