Joint Motion Estimation and Target-Specific Compensation for Simultaneous Inverse SAR Imaging of Dense Fixed-Wing UAV Swarms with Overlapping High-Resolution Range Profiles

Dense fixed-wing UAV swarms can produce overlapping HRRPs, for which echo separation may truncate extended-target responses and propagate reconstruction errors. This paper proposes an ICWE + SPMP + FWDC framework for simultaneous multi-target ISAR imaging. ICWE extracts fixed windows under multi-target masking. SPMP jointly estimates initial range cell locations and radial motion parameters through structured trajectory matching and search-space peeling. FWDC compensates the original mixed echo for each target and coherently combines the compensated components retained by their associated windows. The framework couples target-wise motion estimation with simultaneous focusing of overlapping targets. Experiments using ideal scattering center and electromagnetic simulation data demonstrate comparable visual focusing to the comparison methods under the evaluated low-SNR conditions with HRRP overlap, with less parameter estimation time and lower compensation cost. The results support a model-driven approach to simultaneous imaging without reconstructing individual target echoes.