Dielectric Information Extraction Based on Microwave Scattering Model

The dielectric constant reflects the radiation, scattering, absorption and transmission characteristics of electromagnetic waves. In this paper, the Xingcheng area of Liaoning Province was selected as the research area, and the ALOS PALSAR fully polarized synthetic aperture radar data was used to carry out the dielectric constant inversion of surface media in the study area. Since different microwave scattering models are suitable for different degrees of surface roughness scale range, the perturbation model is suitable for relatively smooth surface, and the Oh model is applicable to a wide range of roughness, so it was proved through inversion that the selected model was applicable to the corresponding research area in terms of roughness degree. The existing perturbation model involves many parameters, which is inconvenient to calculate. During the research, it was found that the inversion process could be simplified by the ratio calculation of the horizontal polarization backscattering coefficient equation and the vertical polarization backscattering coefficient equation. After taking the permeability as constant 1, the model only showed the relationship between the polarizability, wave number, incident angle and relative dielectric constant. Finally, comparing the regional lithologic geological map, it was found that the dielectric constant inversion result of the Oh model was better for the red granite. It was also proved that the Oh model could be used for relative dielectric constant inversion in shallow overburden area.