ISAR Imaging Simulation for Low‐Angle Targets in the Troposphere Based on Ray Tracing Method

ABSTRACT This letter proposes a novel model for inverse synthetic aperture radar (ISAR) imaging of low‐angle targets in the troposphere using echoes simulated by the ray tracing method (RTM). The proposed approach integrates the electromagnetic (EM) wave propagation model with radar imaging techniques to account for the influence of environmental factors, such as atmospheric refraction and ground multipath, on ISAR imaging. First, a spherical multipath calculation method based on the RTM is proposed to acquire path parameters. Subsequently, an environmental transfer function, incorporating path parameters, antenna pattern, and surface characteristics, is created and combined with the target reflectivity function to generate the echo data matrix. Range‐Doppler (RD) processing is then applied to obtain the target's ISAR image. Finally, a typical example is given to validate the correctness and effectiveness of the multipath calculation method. Meanwhile, simulation analysis of ISAR images for an aircraft in flight in a tropospheric environment is conducted. Results indicate that the proposed method effectively predicts the impact of the tropospheric environment on ISAR imaging of low‐angle targets.