Soil moisture inversion method based on three-component decomposition of generalized scattering model

Abstract

The invention provides a generalized scattering model-based three-component decomposition soil moisture inversion method, which comprises the following steps of: firstly, preprocessing a fully polarized synthetic aperture radar image in a crop growth period, and converting an observation scattering matrix into an observation coherence matrix; and establishing a lookup table according to a co-polarization power ratio to obtain an optimal SNVSM body scattering model for a single pixel, establishing an equation relation with an observation coherence matrix residual term (obtained by removing body scattering contribution from the observation coherence matrix) based on an X-Bragg surface scattering model and an improved double Fresnel dihedral angle scattering model, and finally resolving to obtain a soil dielectric constant. And converting into the soil water content through a dielectric hybrid model. The method has the advantages that coherence matrix information is fully utilized through self-adaptive modeling, an underdetermined equation set is converted into a suitable equation set for nonlinear fitting calculation, and inversion can be efficiently and accurately conducted on the soil moisture under vegetation coverage without the help of ground prior data.

Description

technical field [0001] The invention relates to the field of polarimetric radar remote sensing quantitative inversion, in particular to a soil moisture inversion method based on three-component decomposition of a generalized scattering model. Background technique [0002] In the application of precision agriculture, soil moisture is not only an important part of soil fertility, but also an important factor affecting crop growth and development and an important indicator of crop drought disasters. Therefore, accurate estimation of soil moisture is of great value in crop growth simulation and yield prediction. [0003] Traditional soil moisture field measurement methods are time-consuming and labor-intensive, and the scope of investigation is limited. Active microwave remote sensing is sensitive to object characteristics such as the dielectric constant of the scattering target, and the signal has a certain surface penetration, which can continuously monitor the vegetation cov...

AI Technical Summary

Problems solved by technology

However, because the traditional model-based three-component polarization decomposition method is based on the assumption that the scattering particles obey random orientation and uniform distribution, it is difficult to accurately describe the scattering characteristics of the ground surface and vegetation, and there are underdetermined problems in the parameter calculation process, so it is directly applied to The accuracy and universality of soil moisture retrieval still need to be improved

Images