A Spatiotemporal Hybrid Integration Algorithm for Airborne Target Detection and Localization in Multi-Illuminator GNSS-Based Passive Radar

This paper addresses the fundamental power-budget limitation of global navigation satellite system (GNSS)-based passive radar in aircraft detection and localization by exploiting multiple satellite illuminators for spatiotemporal hybrid integration. In contrast to single illuminator operation, cross-link coupling effects, manifested as disparate range and Doppler signatures across individual bistatic links, pose a formidable barrier to coherent energy combination. To surmount this challenge, we first introduce a unified kinematic vector (UKV) that projects the target state into a link decoupled common domain. The UKV encapsulates the target direction of arrival (DOA) and monostatic range, three parameters that remain approximately invariant across all bistatic links sharing a common receiver. Building upon the UKV, we develop an interlink range scaling alignment (IRSA) algorithm that coherently integrates target returns along a UKV-constrained trajectory and project the accumulated energy onto a shared monostatic-range, zero-Doppler grid. This registration aligns target responses from disparate links at a unified spatial coordinate, thereby enabling genuine signal-level fusion across illuminators. When applied across multiple coherent frames, UKV–IRSA elevates sub-noise target energy to clearly detectable levels. Extensive numerical simulations and real-data experiments corroborate the efficacy of the proposed approach.