利用北斗 GEO 卫星干涉信号功率反演土壤湿度

Soil moisture retrieval using Beidou geostationary Earth orbit (GEO) interference signal power was studied. Current researches mainly establish empirical models for retrieving soil moisture. Therefore, a semi-empirical retrieval method was proposed. Taking the advantage of Beidou GEO satellite’s stable geometric configuration relative to the earth, this method utilized the interference amplitude metric obtained in two consecutive days to cancel the influence of the power of the transmitted signal, therefore, achieving the retrieval of the reflection coefficient. Then, based on the reflection coefficient theoretical model under the influence of cross-polarization, a semi-empirical soil moisture retrieval model was constructed. Finally, the proposed method and model are validated through simulations and experiments. The simulation results showed that the proposed method and model can better adapt to the nonlinear situation encountered in the retrieval process. Finally, the experiment results show that the root mean square error of soil moisture retrieval is less than 0.02 cm³ ·cm⁻³, and the correlation coefficient exceeds 0.8.