SAR土壤水分反演中的介电常数实部简化模型

A simplified model of the real part of the soil complex permittivity for soil moisture estimation from SAR image

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,标定其在SAR关键频点下的系数并进行适当改进,最终建立了介电常数实部与土壤体积含水量关系的简化模型.对建立的简化模型进行验证和对比,结果表明,简化模型在精度上优于Hallikainen经验模型,并且与复杂的Dobson半经验模型相比,具有良好的精度和实用性.

A simulated database built with the Dobson semi-empirical model was fitted to the Hallikainen formula by the least square regression method.The coefficients at key frequency points of SAR were calibrated with some improvement.The simplified model between the real part of the complex permittivity and the soil volumetric moisture content was established.It was validated and compared with other models.The results show that the simplified model has better accuracy than the Hallikainen empirical model,and also has good accuracy and practicality compared with the complex Dobson semi-empirical model.