Surface soil moisture is an important parameter in draught monitoring and crop yield estimation, it is important to obtain spatial-temporal soil moisture information in large range. Microwave signal is much related to dielectric constant of object observed, and soil dielectric constant is determined by soil moisture, which was the basis of the use of microwave remote sensing technology for soil moisture monitoring. To solve the transformation of soil moisture and soil dielectric constant, the Dobson semi-empirical model was used to build a simulated database, and then the Hallikainen formula calibrated by the least square regression method at radiometer SMOS( 1.4 GHz), AMSR-E(6.9 GHz), and scatterometer ERS-WCS and METOP-ASCAT (both at 5.3 GHz) frequency-points were performed to set up the simplified models to transform the real part of the dielectric constant to the soil volumetric moisture content. The validations were performed using both simulated data of the Dobson model and in-situ observations, and the results showed that the simplified models had good accuracy and practicability.%为了获取大范围地表土壤水分时窄分布信息,该文开展了微波辐射计／散射计监测介电常数与土壤体积含水率之间的关系研究.微波观测的信号与目标的介电常数密切相关,而土壤含水率是决定土壤介电常数的决定性因素,这是利用微波遥感监测土壤水分的物理基础.该研究针对土壤介电常数到土壤水分之间的转换问题,利用Dobson半经验模型建立模拟数据库,用建立的模拟数据库对Hallikainen关系式进行最小二乘回归法标定,建立了适用于微波辐射计SMOS(频率1.4 GHz)、AMSR-E(频率6.9 GHz)和微波散射计ERS-WCS/METOP-ASCAT(频率5.3 GHz)监测的介电常数到土壤体积含水率转换的简化模型.利用模拟数据和实测数据的联合验证结果表明,简化模型具有良好的精度和实用性.
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