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本文基于微波辐射模型模拟研究了像元尺度内裸露土壤不同空间分布形态的土壤参数对被动微波遥感反演土壤水分的影响.并利用试验数据对采用的模型、算法和模拟研究结果进行了验证.首先,利用地面试验数据对模拟研究中采用的模型和算法进行精度评价;在此基础上模拟了不同空间分布(包括均匀分布,正态分布和随机分布)和异质情况的土壤参数,来研究空间异质性是否会影响土壤水分反演精度,进而寻找空间异质性和土壤水分反演误差之间的关系.最后基于车载微波辐射计开展针对性的地面控制试验,利用所获数据对模拟研究的结果进行了验证.结果表明,本文采用的模型和土壤水分反演算法精度较高(rmse=0.049cm3cm?3),能够满足模拟研究的需要.利用模拟数据的研究结果与实测数据得到的结果吻合良好.被动微波像元尺度内,不同空间分布的裸土参数在被动微波遥感反演土壤水分中会造成不同程度的误差.整体来看,几何随机分布情形下的土壤水分异质性造成的反演误差最大,其次是正态分布,均匀分布由于异质性情况较小,因此引起的土壤水分反演误差最小.
In this paper, based on the microwave radiation model simulation, the effect of soil parameters on the soil moisture retrieval by passive microwave remote sensing was studied based on the spatial distribution patterns of bare soils in pixel scale. The model, algorithm and simulation results were verified by the experimental data. Firstly, the ground test data are used to evaluate the accuracy of the models and algorithms used in the simulation study. Based on this, the soil parameters of different spatial distributions (including uniform distribution, normal distribution and random distribution) and heterogeneities are simulated Spatial heterogeneity will affect the soil moisture retrieval accuracy, and then look for the relationship between spatial heterogeneity and soil moisture inversion error.Finally based on vehicle microwave radiometer to carry out targeted ground control experiments, the use of data obtained by the simulation The results show that the proposed model and the soil moisture inversion algorithm have high precision (rmse = 0.049cm3cm? 3), which can meet the needs of simulation research.Based on the results of simulation data and the measured data The results agree well with the passive microwave pixel scale, the bare soil parameters of different spatial distribution in the passive microwave Inversion of soil moisture will cause different degrees of error.Overall, the geometrical random distribution of soil moisture heterogeneity caused by the largest error of inversion, followed by the normal distribution, uniform distribution due to the heterogeneity of the smaller , So the soil moisture inversion error caused by the smallest.