GPS信噪比观测值的土壤湿度变化趋势反演

土壤湿度变化趋势是某一个位置或区域内水资源循环的重要指标.多路径误差作为一种在导航、定位中的重要测量误差,由于其较弱的空间相关性,难以采用全球甚至区域性模型或差分的方法予以消除.在讨论和研究了多路径误差反射模型的基础上,实现了利用 GPS信噪比 SNR(Signal - to - NoiseRatio)观测值中的多路径反射分量对土壤湿度变化趋势的模拟.结合实测 GPS数据和土壤湿度计观测数据的对比和分析表明,该方法能反映土壤湿度变化趋势.同时,在计算过程中如何选择合适卫星、对反演结果质量进行评价以及如何实现两种观测结果之间的同化等是进一步需要研究的问题.

Inversion of Soil Moisture Fluctuation Based on Signal-to-Noise Ratio of Global Positioning System

Soil moisture and its fluctuation play an important role on reflection of the water resources recycling at a certain position or within a region.As a kind of significant measure noises,the multipath error is difficult to remove by global or regional models or differential ways because of the weak spatial correlations.Based on discussion on multipath reflection model,how to use the GPS signal-to-ratio observables to model the fluctuations of soil moisture was presented and realized.With the observed GPS and soil moisture data through soil water probe,the comparisons and analysis were conducted.And the results showed that there was the possibility to reflect the fluctuation of soli water content.Meanwhile,how to select the proper satellites,how to evaluate the quality of the inversion and even how to unified the two kind of results were the problems to be considered in future.