Effective path of SAR double bounce scattering between trees and undulating terrain

A computation method for effective path of SAR double bounce scattering from trees and undulating terrain is presented. The large-scale elements of surface fitting are used to describe the variation of surface slope. The situation that there may be none or many effective paths of double bounce scattering from trees when the terrain is undulating with large-scale feature is fully considered through conditional searching. In order to improve the computation efficiency, the forest stand is divided into three-dimension grids. The conditional searching for the scatterers in a certain grid is based on the searching results of the centre of the grid. The computation results on measured DEM by LiDAR at Culai mountain in China are demonstrated. It is shown that the method proposed by this paper can effectively characterize the double bounce scattering from trees based on undulating terrain compared with the results based on tilted ground with single slope.