Research And Application Of Snow Parameters Through Ground-Based GPS Remote Sensing

Snow is one of the most active natural elements on the earth's surface,snow cover changes have a major impact on the global water,energy cycle,social economy and ecological environment.Therefore,the detection of snow information is of great significance to the scientific research of global water resources,climate and environment.With the continuous improvement of the GNSS system and the continuous expansion of the application field,the inversion surrounding environment parameters around the station based on the SNR information influenced by multi-path effects represented by GNSS-MR technology has become a new research hotspot,which makes ground-based GPS remote sensing develop vigorously in the field of surface monitoring.Based on the research results of scholars at home and abroad,this paper carried out research on the inversion of snow depth by GPS-MR technology in Altay and analysis of snow density simulation and snow water equivalent estimation combined with GPS-MR technology and observation data from SNOTEL station.The main research contents and innovations of this article are as follows:1.Explained the concept of multipath and SNR,and discussed its spatio-temporal characteristics and influencing factors.On this basis,the correlation between multipath and signal-to-noise ratio is analyzed in detail,and it is pointed out that the signal-to-noise ratio is seriously affected by the multipath effect at low altitude angles,and the reflected signal contains surface environmental information.The method of polynomial fitting is used to peel off the multi-path reflection signal,and then the signal-to-noise ratio information influenced by multi-path is used to achieve the inversion of the surface environmental parameters.2.This paper describes the principle and method of retrieving snow depth by GPS-MR technology in detail,and gives the inversion process and calculation method.Combined with the measured data of the Altay Snow Monitoring Station in Xinjiang,the influence of the parameter setting of the GNSS observation data on the GPS-MR inversion accuracy was analyzed.3.Based on the analysis of the correlation between snow depth and snow cover density,this paper describes the simulation of snow density,the method of snow water equivalent estimation and the steps of building an empirical model.In addition,the technical route and process for constructing snow cover density simulation and snow water equivalent estimation model are given.Furthermore,the validity of this model and the simulation accuracy are verified combined with the measured data from GPS station and SNOTEL site.The experimental results show that this model can effectively simulate snow cover density and snow water equivalent estimation.