Simulation study of atmospheric ducting impacts on maritime target ISAR using the parabolic equation method

This letter proposes a simulation method for maritime target inverse synthetic aperture radar (ISAR) imaging under atmospheric ducting conditions,based on the 3-D parabolic equation (PE) method. First, the PE is introduced to model the radar wave propagation and obtain the field illuminating upon the target. Then, a phase-containing pattern propagation factor, incorporating path information, atmospheric medium characteristics, sea surface properties, etc., is created and combined with the target reflectivity function to generate the echo data matrix. Subsequently, the ISAR image of the target is reconstructed through Range-Doppler (RD) processing. In addition, a field calculation method based on the discrete Fourier transform (DFT) form of the 3-D PE solution is developed to address the PE's limitation in directly obtaining field information at arbitrary spatial positions. Finally, numerical simulations under flat-sea conditions validate the effectiveness of the proposed approach, and ISAR imaging results of a ship target near the radar line-of-sight edge under different atmospheric ducting scenarios are presented and analyzed.