Inversion Of Vegetation Height Based On Polarimetric SAR Interferometry

Polarimetric SAR interferometry is a combination of interferometric SAR and polarization SAR techniques.It combines the ability of polarization SAR to acquire target scattering properties and the ability of interferometry SAR to acquire the spatial distribution of target scatterers.Polarimetric SAR interferometry technology improves the measurement accuracy of traditional interferometry SAR,and it can better acquire the target scattering mechanism.Polarimetric SAR interferometry technology utilizes all-polarization data and can significantly improve the inversion accuracy of surface parameters through the correlation matrix eigendecomposition technique,thereby providing a possibility for obtaining high-precision digital elevation information.This paper mainly studies the method of high-level inversion of ground vegetation in polarimetric SAR interferometry.At the same time,it conducts detailed research on polarization coherence tomography algorithm.The main work is as follows:(1)Analyze the characteristics of the scattering mechanism for different polarimetry and their sensitivities for vegetation regional;study the optimization of the polarization interference coherence coefficient.At the same time,the phase center estimation of the ESPRIT algorithm is analyzed in depth,and the performance of the algorithm is verified through simulation data.The experimental results show that based on the ESPRIT algorithm,the vegetation canopy and the surface phase center can be well estimated,and separate the phase center of the vegetation scattering body.(2)Research phase coherence fusion inversion algorithm,and the complex coherence amplitude inversion algorithm is used to make up for the DEM difference algorithm.This algorithm effectively reduces the influence of factors such as depolarization in the ESPRIT algorithm on the height estimation.In the DEM difference algorithm,study the selection and phase jump of the ground phase polarization mode.Experiments show that after median filtering,the HH-VV polarization mode can accurately estimate the phase of the ground surface;in the complex-coherence amplitude algorithm In this paper,the optimal coherence coefficient and the scattering model function are used to invert the high-precision vegetationheight.Finally,analyze the role of the weight coefficient in the phase-coherent fusion algorithm.The accurate vegetation height estimation was obtained through experiments and the validity of the phase coherent fusion inversion algorithm was verified.(3)In-depth study the polarization coherence tomography algorithm.The principle of the polarization coherence tomography algorithm is clarified,and the steps of the single baseline polarization coherence tomography algorithm are deduced.The vegetation co-occurrence estimation and the Legendre coefficient of the phase coherence fusion algorithm are mainly performed,and the simulation data experiment proves that the algorithm can acquire vegetation height and vertical structure scattering characteristics of the vegetation.