Analysis on Near-field Electromagnetic Scattering of a Ship on Sea Surface based on High-frequency Technique

A near-field physical optics formulation on high-frequency method, which is based on the expanded phase approximation of the Green’s function, is presented to simulate the electromagnetic (EM) scattering of an electrically large size target of interest in the near-field zone. This method is shown to be more general at no extra computational cost, it differs from standard formulations and is better suited to near-field computation. Most of the times, vessels in naval scenario are observed in near-field zone. Under the Fraunhofer limit, nearfield scattering characteristic of the target is thus a function of observation angle and radar range.