Soil Moisture Inversion By Means Of IEM And The Dual-polarization TerraSAR Data

As an important part of the soil, soil moisture is basic material for plant. It restricts the crop yield, determines the surface energy to heat and latent heat of transformation of allocation proportion, the proportion of surface water infiltration and formation of surface runoff. In addition, it influences the distribution of land sueface vegetation.Remote sensing has the characteristics of monitoring of a wide range and obtaining spatial continuity images. It attracts more attention in the study of soil moisture.In recent year, four models have been frequently mentioned in soil moisture inversion, which are Oh model, Dubois model, Shi model and IEM model. The current research methods of bare surface soil moisture are discussed. We analyzesd the advantages and disadvantages of each model and use scope in this article.Thus, the research direction of inversion the exposed surface soil moisture is aiso proposed.The reaction of radar backscatter coefficient to different groud paramenters, are simulated by the IEM model. Then, the variation law of radar backscatter coefficient fllowing these paramenters are revealed. The parameters setting of ideal system in inversion surface soil moisture SAR is studied and discussed.According to the characteristics of study area and radar data, the IEM scattering model was used to simulate the characteristics of the exposed surface. This paper mainly analysis the relationship between the radar backscattering coefficient and soil moisture as well as surface roughness parameters. The empirical model of surface roughness inversion using scattering coefficient difference of co-polarization(VV and HH) is proposed. And based on the proposed model, another empirical model of surface soil moisture inversion using radar backscattering coefficient(HH) is established.To demonstrate the mechanics of the new models, a case study of Shendong mining area is presended in this papar. Spatial distribution information of surface soil moisture in study area is extracted and the precision of inversion model is evaluated. The correlation coefficient that relative error between soil moisture of mode is 0.744. Therefore, the precision of inverse soil moisture is verified and the reliabiling of established empirical model is proved.