BeiDou/GNSS for surface multi-parameter monitoring in permafrost regions

The active layer of permafrost has a periodic variation law. Using traditional measurement methods to monitor the deformation of permafrost cannot meet the needs of high-precision and low-cost continuous observation, and GNSS positioning technology can solve these problems well. However, the cost of monitoring system using traditional geodetic receiver is high, which limits the popularization of this technology. In order to improve the universality of frozen soil monitoring, this paper proposes to use a universal BeiDou/GNSS receiver for monitoring combined with power supply system and Internet of Things technology to form a universal frozen soil comprehensive monitoring system. The precise point positioning (PPP) technology is used to obtain the ground deformation of frozen soil and invert the atmospheric precipitable water, and the Global Navigation Satellite System Interference Reflection (GNSS-IR) technology is used to invert the surface environmental parameters of frozen soil area, so as to realize the comprehensive monitoring of multi-parameters in frozen soil area. In order to ensure the quality of GNSS data, the Anubis software was used to comprehensively analyze the data quality of the observation files. The results show that under normal circumstances, the signal-to-noise ratio and multipath error of the observation data meet the requirements, the data integrity rate is low, and the cycle slip ratio of some observation data is higher. The frozen soil deformation calculated by the four-system fusion is better than that of the single BeiDou and single GPS systems in terms of accuracy and stability. The PWV and snow depth sequences obtained by multi-system fusion can better reflect the changes in the station environment. The inversion results of soil moisture can be well matched with the ERA5 soil moisture product. The universal BeiDou/GNSS monitoring system provides an efficient and economical scheme for monitoring ground deformation and environmental parameters in permafrost regions. It provides data support for permafrost disaster warning and permafrost degradation assessment, and expands the application value of BeiDou/GNSS monitoring in permafrost regions.