An analytical model of double scattering for SAR imaging of urban structures

An analytical solution of double scattering for urban structures is proposed. This model is based on geometrical optics (GO) and first order small slope approximation (SSA1), thus has a wider scope of application than classical analytical models. In our model, the surface of building is assumed to be smooth and the ground is regarded as Gauss rough surface, then a closed form can be obtained. The radar cross section (RCS) and SAR images of double scattering for buildings surrounded by grass are simulated respectively. By comparing the real and simulated images, it shows that this model can accurately exhibit the effects of aspect angle on the double scattering feature in SAR image. This model is believed to possess great value in SAR image simulation and feature extraction of urban scene for its easy implementation and clear physical interpretation.