Single-UAV Synthetic-Aperture Passive Localization via Spatial Vector Backprojection

High-precision passive localization with a single airborne platform remains challenging due to low SNR, navigation errors, and attitude jitter. Traditional single-UAV methods suffer from limited accuracy and weak elevation observability, while multi-UAV schemes - though improving geometry - introduce synchronization and configuration constraints. To address these issues, this paper proposes a spatial-vector backprojection(SVBP) algorithm for single-aircraft, single-antenna passive localization. Exploiting platform motion to form a virtual synthetic aperture, SV-BP builds a trajectory-consistent spatial guidance vector directly from the measured flight path and performs coherent backprojection via subspace projection over the region of interest, enabling high-precision localization. The scene is parameterized by slant range and squint angle, and solved with a compact coarse-to-fine R-θ search that reduces computational load while preserving resolution. Simulations demonstrate marked accuracy gains over representative singlestation methods and strong robustness to YPR(yaw, pitch, and roll) jitter and navigation perturbations, indicating promising potential for onboard, real-time deployment.