Influence Factors and Performance Degradation of Space-to-Space ISAR Imaging Induced by Orbital Mutual Inclination and Altitude

In recent years, the concept of utilizing space-based inverse synthetic aperture radar (ISAR) for space situational awareness (SSA) has been proposed, attracting significant attention in the field of orbital target imaging. The relative motion analysis between the radar and the target is crucial to ISAR imaging research. For space-to-space ISAR imaging, the orbital parameters of both the platform and the target significantly impact the relative motion during the imaging process. These parameters affect imaging accumulation time and angle and consequently degrade imaging performance. In this article, a space-to-space ISAR imaging geometric model was established based on the orbital characteristics of satellite operations, and the influence of relative orbital parameters, such as orbital mutual inclination and altitude, on imaging conditions-including detectable duration and imaging accumulation angle-was analyzed. Additionally, the imaging influence factors for eight typical scenarios of space-to-space ISAR imaging were thoroughly discussed. The study delves into the effects of orbital mutual inclination angle and altitude on the imaging projection plane (IPP), motion errors, and the degradation of focusing performance. This article provides a reference for the research on motion compensation technology in space-to-space ISAR imaging and the development of space-to-space ISAR systems.