Abstract:

The modeling and electromagnetic scattering characteristics of composite rough surface of ground and ocean in adjacent region are studied. The Monte Carlo method is applied to construct composite rough surface of ground and ocean in adjacent region, Gauss spectral function is used to simulate actual ground surface, and joint north sea wave project （JONSWAP） spectral function which is combined with shallow coefficient is used to simulate actual near sea surface. Based on the theory of composite rough surface modeling, different weighted inverse tangent functions are presented to realize diverse actual environments, such as adjacent region with linear boundary, crescent boundary, and valley boundary. The couplings of facets in respective region and facets of region near borderline are considered, and an iterative physical optics (IPO) based on facets of composite rough surface of ground and sea in adjacent region is presented. The fast far field approximation (FaFFA) and partial coupling technology are applied to accelerate the process of IPO. The curves of bistatic scattering coefficient (BSC) of ground rough surface, sea surface and composite rough surface are compared. Electromagnetic scattering characteristics of composite rough surface are analyzed. The influences of polarization, incident angle, shape of borderline, root mean square (RMS) and correlation length of ground rough surface, wind velocity of sea surface on BSC are discussed. Based on the electromagnetic scattering field of composite rough surface which is calculated by IPO, the synthetic aperture radar (SAR) images of composite rough surfaces with special boundaries are obtained by the Rang-Doppler method with the stripmap mode. The influences of relative dielectric constants of ground rough surface and sea surface on SAR imaging are discussed. This research includes construction of an adjacent environment model, calculation of the electromagnetic scattering field, and application of SAR imaging technology. The simulation results show the characteristics of the SAR image of the composite rough surface, which can be a reference for detection, remote sensing and inversion of the electromagnetic characteristics of the environment of ground and sea in adjacent region.