Results of soil moisture inversion from radiometer biased by periodic change of row structure on farmland
农田垄行结构对被动微波遥感土壤壤湿度反演的影响

The discrete method is used to simulate emissivity of one dimension of rough surface with row structure. Compared to the emissivity measured by ground radiometer, the bias between measured and simulated emissivity is less than 0.01, and this conf irms that the discrete method is feasibility to simulate emissivity of rough surface with row structure. At a given row structure, the difference of emissivity between row structure and fl at smooth surface changes with observed azimuth angle, and the value falls in the range of 0.02 and 0.05. This indicates that emissivity of row structure surface is anisotropic, and it should be considered in the process of modeling microwave radiation of row structure surface. In addition, the error of soil moisture inversion caused by neglecting the existence of row structure is analyzed across different soil moisture, and results show that the absolute error of soil moisture is between 0 cm3/cm3 and 0.1 cm3/cm3 when soil moisture changes from 0.02 cm3/cm3 to 0.5 cm3/cm3. This error is greater than the error tolerance limit of soil moisture inversion. Therefore, in the process of farmland parameter inversion from passive microwave remote sensing, surface row structure effect cannot be ignored.