Study on the characteristics of composite electromagnetic scattering from actual terrain surfaces with multiple targets

In order to meet the needs of the acquisition and characterization of target radar echo characteristic data in the actual ground object environment, the four-component model proposed by Wang and Schmugge was adopted to simulate the dielectric properties of soil. In addition, the digital elevation model (DEM) was used to accurately depict the inhomogeneity of the terrain surface, and the electromagnetic scattering behavior under complex terrain and multi-target conditions was analyzed by using the finite difference in time domain method (FDTD). In this study, the angular distribution characteristics of the composite scattering coefficient are described, and the specific effects of many factors such as incident angle, wavelength, soil moisture, number of scatterers, scatterer spacing and burial depth on the scattering coefficient are comprehensively discussed. The results show that the composite scattering coefficient shows an obvious oscillation phenomenon with the change of scattering angle, and the scattering intensity is significantly enhanced in the specular reflection direction. In addition, the composite scattering coefficient shows the following trend: it gradually decreases with the increase of the angle of incidence, increases with the decrease of wavelength, increases with the increase of soil moisture, increases with the increase of the number of scatterers, increases with the expansion of scatterer spacing, and increases with the deepening of the buried depth of the scatterers. This study provides important theoretical and practical guidance for understanding the electromagnetic scattering behavior of targets in complex terrain and optimizing electromagnetic wave detection systems, especially for target detection and recognition in changing environments.