针对传统雪深测量缺乏必要时空敏感性的不足,该文在分析GPS信号多路径反射模型的基础上,利用GPS信噪比观测数据,通过分离提取多路径反射分量研究其时频特性,探讨GPS多路径信号与雪深及其变化关系并进行反演建模。依据菲涅尔反射区理论,确定了反射区域范围,进一步探讨卫星、波段选择及初始反射高度确定等。对比实验研究表明,反演结果与实测值吻合较好,相关系数为0.93,均方根误差为8.6cm;信噪比多路径反射分量的频率能有效跟踪积雪深度的变化。
In view of the lack of necessary space time sensitivity of traditional snow depth measurement, multipath was extracted from the GPS SNR and its time-frequency characteristic was analyzed based on discussion on multipath reflection model, the relationship between GPS multipath signal and snow depth and its variation was investigated by modeling in this paper. The range of reflection area was determined based on Fresnel effect theory~ moreover, the choice of satellite and band, and the determina- tion of initial reflection height were discussed. The results showed that the inversion results were in good agreement with the measured values, and the correlation coefficient was 0.93, the RMSE was 8.6 cm; the frequency of multipath signals could effectively track the variation of the snow depth.