Influence Factors of Space-to-Space ISAR Imaging Induced by Radial Impulsive Thrust

As space activities rapidly evolve from static deployment to dynamic interaction, the demand for space-based imaging of on-orbit targets has significantly increased, garnering widespread attention. Most current space-based imaging models focus on static scenarios, and systematic studies on space-based inverse synthetic aperture radar (ISAR) imaging technology—especially for dynamic interaction scenarios—remain scarce. This paper examines the imaging characteristics of a space-based ISAR system observing space targets under radial impulsive thrust. Based on orbital dynamics, a maneuver-induced space-to-space imaging geometry model is constructed, along with the derivation of the corresponding slant-range model and echo signal formulation. The effects of varying radial impulsive thrust magnitudes on key imaging parameters between two satellites are systematically analyzed, and the feasibility and constraints of maneuver-induced ISAR imaging driven by radial impulsive thrust are evaluated. In particular, a co-orbital configuration is adopted to deliberately suppress natural line-of-sight (LOS) variation caused by orbital altitude differences and mutual inclination, such that the evolution of the imaging geometry is dominated by the maneuver itself, enabling a clearer interpretation of maneuver-induced imaging mechanisms. The results reveal that favorable imaging conditions emerge only when the maneuver drives the observation satellite into a close-approach regime, forming time windows with practical imaging value. Meanwhile, although radial impulsive thrust accelerates angular accumulation under high-resolution conditions, it also reshapes the imaging projection plane (IPP) and strengthens motion-induced phase errors, thereby imposing stricter requirements on compensation accuracy. The study provides a useful reference for modeling, evaluation, and strategy design of space-based ISAR in maneuvering scenarios.