C波段多极化SAR反演土壤水分研究

【目的】研究不同极化方式下雷达后向散射系数与地表土壤含水量之间的关系。【方法】在分析不同地表微波散射模型基础上,选用合适的植被散射模型结合多极化雷达数据从雷达总的后向散射中去除植被影响,建立土壤后向散射系数与土壤含水量的关系。【结果】拟合HH极化、HV极化雷达观测数据与土壤水分数据,相关系数为HH极化R2=0.5523,HV极化R2=0.3579。【结论】微波具有全天候、穿透性以及不受云层影响的独特物理机制,使其在研究大尺度土壤水分反演时效果较好,相比较HV极化,HH极化雷达影像数据更适合干旱区作物植被覆盖地区土壤水分监测。

A Study on Soil Moisture Retrieval by C-band Multi-Polarization SAR

Objective]The present study was designed to examcne the relationship between radar backscatter coefficient and surface soil moisture in different polarization mode.Method]Based on different surface microwave scatter model,appropriate vegetation scatter model combined with multi-polarization radar data were selected to wipe off the effect of vegetation from the radar total backscatter,the relationship between soil backscatter coefficient and soil moisture content were established.Result]Fitting soil moisture data and the observation data from radar HH polarization and HV polarization,the result indicated that the R2 of HH polarization is 0.552 3,and the R2 of HV polarization is 0.357 9.Conclusion]Because of the distinctive physical mechanism of all-weather,penetrability and not being affected by cloud,microwave remote sensing has its own advantages to discriminate to extract soil water content in large scale regions.Compared with HV polarization,HH polarization radar data is more efficient technical means for remote sensing monitoring of soil water content in arid area.