Soil Microwave Remote Sensing Mechanism

Microwave remote sensing has developed very fast from the 60's due to its advantages. In the microwave remote sensing, research on the bare soil is very significant. As an important parameter of ecology, soil moisture is very important for soil remote sensing application. Therefore, it is necessary to build up the measurement system in lab to study the principle of soil microwave remote sensing. For this purpose, this paper has done a lot of study on simulation of backscattering models for rough surfaces, establishing the measurement system of complex dielectric constant within lab, including the open measurement system of backscattering constant.At first, this paper introduces the application of Power-law spectrum in the backscattering models, including its advancement and disadvantage. What's more, this paper has studied the simulation characteristic of IEM model and also made an analysis on the improvement of the model. About the IEM, this paper not only analyzes how the dielectric constant of soil has an influent on the backscattering argument, but also it advances new method about the IEM according to the result of simulation.In addition, this paper introduces a simple but practical measurement system based on the Transmission/Reflect theory. And we improve the traditional measurement system because of its localizations. In the measurement system, we adopt the nonstandard calibration and analyze its disadvantages. Then, the electrical length calculation method is put forward so as to locate the calibration plane and the sample reflect plane. What's more, this paper analyzes the effect of the different sample length on the calculation of complex dielectric constant especially that of thick sample. Also, we analyze the error that may be taken into the complex dielectric constant calculation, using different length waveguides with sample. Finally, the single port measurement formulations are also extrapolated and validated in the experiment. To sum up, this paper has rally elaborated these special problems about the measurement on the complex dielectric constant of soil.Last but not the least, this paper introduces the basic principle of open backscattering measurement system, the conditions of the system availability, and the principle of system scaling methods. Also, we have compared the basic method to otherdifferent methods of surface parameters calculation, preparing for the study of soilbackscattering.