Anotace:
Based on the solutions of physical optics (PO) and physical optics of diffraction (PTD), we propose a modified parametric scattering center model for high precise signal simulations of extended targets. Different from geometrical theory of diffraction (GTD), which is commonly used in the existing models, the solution of PTD represents the individual scattering contribution of edge diffraction, and can precisely describe the scattering field under full observation angles and polarizations. This model has higher precision than the existing ones, especially for the targets with dominant scattering centers induced by diffraction. And this model is physical where the parameters are related with geometry of the targets. To validate this model, four conducting targets with dominant contributions of diffraction are simulated in this study. The radar cross-sections (RCS) and the time-frequency representations (TFR) of backscattered waves simulated by this model are compared with those computed by a full-wave numerical method, as well as those simulated by a commonly used scattering model. The comparisons show that the results of this model have better agreement with those of the full-wave numerical method than the existing model.