Parameter Inversion Model For Targets Beneath Canopy Using PolInSAR Images

Polarimetric SAR interferometry (PolInSAR) is the technique that integrates SAR polarimetry and SAR interferometry. The interferometric analysis of a full coherent polarimetric data set enables the combination of final structure properties and spatial information of the targets. PolInSAR allows a more sophisticated physical interpretation of scattering mechanism. PolInSAR has extented the applications of SAR remote sensing, and has wide and latent prospective applications and valuable researching aspects.PolInSAR has been used to invert vegetation parameters of terrain surface by the backward scattering model, especially for height of forest. These parameters are the bases of terrain classification and target detection and recognition. Therefore, deriving correct scattering model is the bases of terrain surface vegetation parameters inversion and deriving different kind of backward scattering model has been hot research topics in polarimetric interferometry in recent years.Parameter inversion model for targets beneath canopy using PolInSAR images is discussed in detail in this dissertation. The main contents include Polarimetric Interferometric Phase Coherence Optimization (PIPCO), Random Volume over Ground (RVoG) coherence scattering model in vegetation area and RVoG coherence scattering model in the area of tagets beneath vegetation, and simulation model generating PolInSAR data.Firstly, this dissertation provides an overview of basic theory of PolSAR, such as representation of polarimetric scattering characters of targets and elementary scattering mechanisms. Then theory of InSAR and all kinds of decorrelation factors are discussed. Furthermore, the principles of polarimetric interferometry and the theory of global space coherence optimization are discussed in detail.Secondly, scalar coherence scattering models and vector coherence scattering models are studied. The study is focused on the RVoG scattering model. The influences upon coherence of all the parameters in the model are discussed. Thirdly, after in-depth discussion of RVoG scattering model in vegetation area, the characteristic of area of man-made target beneath vegetation is studied. The scattering models in this case are derived with two methods and compared.Finally, a simplified three-level scattering model is used as the input of the PolInSAR system to get the simulation data that is used to explain whether the new scattering model is reasonable. The results of the experiments are then discussed in detail. The results show that the new scattering model can extract the parameters of the man-made target besides the parameters of the vegatation.