Numerical Simulation of Micro-Doppler Characteristics of Ships Based on EM Scattering Model

When a ship moves on a dynamic sea, apart from the translation caused by its velocity, it also has micro rotation motions caused by the interaction between the ship and the ocean waves, i.e. the roll, the pitch and the yaw, which leads to the micro-Doppler features of ships. This paper focuses on the study of the micro-Doppler characteristics of ships on a dynamic sea because it can provide a way for inversion of the target's state of motion, which will benefit the detection and recognition of ships in a marine environment. For this purpose, the radar echo of a ship target is simulated based on its scattering characteristics and the radar parameters. In this process, the scattering characteristics of the target is estimated with the famous geometrical optics and the physical optics (GO-PO) hybrid method. Then, the micro doppler spectrogram is calculated with the short-time Fourier transform (STFT). With this procedure, the micro doppler spectrograms of the ship target with different types of micro motions are simulated. The numerical results show that the amplitude and the period of motion can be estimated with the micro doppler spectrogram, which will benefit the target detection in a marine environment.