Research On Bare Surface Soil Moisture Inversion Based On The Microwave Remote Sensing

Surface soil moisture system plays a very important role in the earth’s ecological, It not only has a very important role in control for the migration and the circulation of the surface evaporation and groundwater, and at the same time, the surface soil moisture also plays a very important role in hydrology, climatology, agriculture, ecology and other fields of multidisciplinary research, so real-time monitoring of time and space distribution of surface soil moisture information has become an urgent need to solve the problem.The studies show that active microwave remote sensing to compensate for optical remote sensing, the defects in passive microwave remote sensing soil moisture monitoring application, for the main method of Large area of the surface soil moisture monitoring at present.For active microwave remote sensing, the launch of the interaction between electromagnetic wave and ground targets in radar process, influence factor, the surface scattering characteristics of a series of parameters, one of the most important influence factor is soil moisture and surface roughness. So the study of these two parameters for microwave scattering model is very important.In this paper, the main contents and results as follows:(1) this paper uses the RADARSAT2radar image data, useing ENVI4.8software for the RADARSAT-2data in the study area for calibration, geometric correction and image filtering, etc.(2) The existing theory and experience, the semi-empirical microwave scattering model comparative analysis, determining the scope of the use of these models and the advantages and disadvantages. Finally choosing AIEM model as the bare surface scattering model of soil moisture inversion experience of the study area.(3) The AIEM model database for bare surface microwave scattering characteristics)f simulation analysis and research, through the same to the poor, cross polarization scattering coefficient after polarization scattering coefficient difference and the elationship between the soil moisture, the surface roughness parameters analysis, established the concrete surface roughness in the study area, soil moisture inversion nodel. established the concrete surface roughness in the study area, soil moisture inversion model.(4) Established experience model is applied to the cold dry irrigation area, according to the already processed good RADARSAT-2the radar image data inversion in the study area, obtain the soil moisture spatial distribution. The soil moisture inversion simulation data correlation analysis with experimental data and the cross polarization combination VV-VH soil moisture inversion values and measured values of the highest degree in related, reached0.8927. For the purposes of this research area of bare soil moisture inversion accuracy is the highest cross polarization combination plan VV-VH, the result is basically in conformity with the scholar’s research results before, can well reflect spatial distribution of soil moisture of he-tao irrigation area.