小波多尺度和多星融合的GPS-IR土壤湿度反演

GPS-IR Soil Moisture Inversion Combined with Wavelet Multi-Scale and Multi-Star Fusion

全球定位系统干涉反射测量GPS-IR(Global Positioning System Interferometric Reflectometry)是利用多路径信噪比反射分量参数幅度、相位、频率的变化监测地表环境的技术。针对多路径信号中同时包含卫星直射信号和反射信号,传统低阶多项式难以准确提取卫星反射信号有效参数的问题,本文利用小波分析对卫星直射、反射信号进行分离,准确获取卫星反射信号,利用熵值法多星融合模型反演土壤湿度。经理论和实验研究表明:该方法能够更为精确地反映测站周围土壤湿度的变化,有效改善了部分异常跳变现象。相关系数为0.914,相比单星反演模型至少提高18.4%。

Global Positioning System Interferometric Reflectometry(GPS-IR)is a technique for monitoring the surface environment by using the multipath SNR reflection component parameter amplitude,phase,and frequency changes.Aiming at the problem that the multipath signal contains both the direct satellite signal and the reflected signal,the traditional low-order polynomial is difficult to accurately extract the effective parameters of the satellite reflected signal,the direct and reflected signals of the satellite are separated by wavelet analysis to obtain the real reflection signal,and the soil moisture is retrieved by the entropy method multi-star fusion model.Theoretical and experimental studies show that the method can more accurately reflect the change of soil moisture around the station and effectively improve some abnormal jumps.The correlation coefficient is 0.914,which is at least 18.4%higher than the single-satellite inversion model.