The GNSS observations quality can be affected by the environment around the station.Using the signal-to-noise ratios to correct the observation influenced by multipath effect has attracted attention of many scholars.Meanwhile,using GNSS-MR technology based on SNR information to study environmental changes around the station has become a new research subject.And that makes the GNSS active in the field of remote sensing.Firstly,the relationship between GPS multipath and SNR is analyzed in this paper.Then,based on the SNR and the signal amplitude variation,the basic principle of GPS-MR technology is given.GPS observation data in P351 and SNOTEL station snow data are used to evaluate the effectiveness of the algorithm.Also,satellite reflection point trajectory and satellite selection of snow depth detection are further analyzed.The experimental results show that: GPS-MR can be used to measure the snow depth,and its detection precision is 0.08 m.GPS-MR technology not only can make full use of multipath effect,but also provides a development space for GPS technology using in the surface environment monitoring.