Soil Moisture Inversion Modeling Based On GPS Reflectometry

GPS Reflectometry, making use of L-band GPS signal, is a kind of remotesensing methods to sense physical properties of land surface. Based on multipatheffects and relationship between GPS signal characteristics and land surfaceenvironmental parameters, GPS-R has been recognized that it is possible to study onproperties of the reflection region around GPS station.This thesis focuses on the methodology and modeling for soil moisture inversionwith GPS-R. Firstly, it described the relationship of soil moisture and the reflectioncoefficient of land surface soil. Moreover it analyzed the relationship of GPS satelliteelevation angle and the reflection coefficient of land surface soil, which was taken toimprove the inversion model of soil moisture.Secondly, the thesis introduced four signal processing approaches for remotelysensing soil moisture. In terms of low-layer soil moisture experiment for land surface,signal transmission loss was corrected with the application of PO scattering model.Then, according to principles of GPS Reflectometry, it proposed weighted model ofsoil moisture. After performing GPS reflected signal and soil moisture observationbefore and after watering in the experimental area, improved model of soil moistureretrieved by GPS Reflectometry was studied according to three experiments.Finally, some conclusions were made and further researches related to this themewere suggested.