GPS-R技术辅助的土壤水含量变化监测

Monitoring of Soil Moisture Fluctuation in Mining Areas Based on GPS-R

针对传统地表土壤含水量测量方法时空分辨率小等不足,研究一种基于GPS卫星信号的矿区地表土壤水含量反演算法。针对傅里叶变换难以处理非均匀时序数据,设计了一种Lomb Scargle算法分析GPS信噪比特性。直接分离其中的直射信号和反射信号,提取多路径反射信号并分析其时频特征。通过与实测数据对比,分析反演土壤含水率的可行性。结果表明:反射信号频谱特征与实际数据具有较强的相关性。该方法为高时空分辨率监测地表土壤含水率提供了一种新的思路。

Traditional methods for measuring soil moisture of land surface have lower spatial resolution. A promising algorithm for monitoring land surface soil moisture based on GPS satellite signals was discussed in this paper.For the difficulty to handle non-uniform time series data through Fourier transformation, the Lomb Scargle Fourier transformation was introduced in the algorithm, Within it, multipath is extracted from the GPS SNR feature through the separation of the direct and reflected signals. With time-frequency analysis method, we analyzed the feasibility to monitor soil moisture by comparison with the on-site observation data. The results indicated that spectral characteristics of the reflected signal were strongly correlated with soil moisture. It is a promising approach to receiving soil moisture with high spatiotemporal resolution in mining areas.