Based On Soil Moisture Inversion Method Of Sar Image

Soil moisture is an important part of earth’s water cycle,as an important indicator plays an important role in hydrology, meteorology, agriculture and other fields of research. Therefore, the accurately monitor of soil moisture is very important, and has always attracted people’s attention. It is difficult for us to obtain a wide range of surface soil moisture spatial information in the short term based on the traditional measurement method, has not been able to satisfy performance requirements for speed and large range of soil moisture monitoring. Microwave remote sensing in particular active microwave remote sensing technology development, has laid a foundation.for fast, accurate monitoring of large area surface water content information. This study is analysis the characteristics of active microwave remote sensing, with the imge data features of Multi-polarization ASAR and parameters set of Single polarization SAR as research foundation, study the suitable semi-empirical model for soil moisture inversion.In the aspect of theory, this paper based on Integrated Equation Model (AIEM) and Water Clud Model, analysis the characteristics of microwave scattering for bare and vegetation covered surface soil. First of all, using the simplified formula of backscattering coefficient with soil water content and roughness developed a inversion model of bare soil moisture used for Multi-polarization ASAR data. Secondly, based on the AIEM, developed a inversion model of bare soil moisture used for single polarized SAR data.Finally, using the land-based scattering data of measured in winter wheat ground established wheat Water Clud Model, while access to the correspondence between vegetation water content and polarization difference.Based on identified wheat Water Clud model established water content inversion model under vegetation covered surface.In the application of the results, We apply inversion arithmetic in the testing area of Qiong Lai city.Using the two ASAR images wo have acquired of Qiong lai city into the Multi-polarization semi-empirical inversionmodel of soil moisture, obtained the spatial distribution of soil moisture about the testing area. At the same time, using S-band land-based scattering measurement data into single polarization inversion model, got the inversion values of water content.The correlation between the results by using the model of soil moisture and measured datas are better,proved that these modelsof soil moisture inversion are simple and effective used to the testing area, and can be used can be used for the inversion of a large area of surfaces soil moisture.