Stability analysis of the GNSS reference stations for displacement monitoring

Satellite measurements are of great importance in monitoring the deformations of the Earth's crust, which have resulted from the impact of natural forces and human activities. The example of human activities that cause surface deformations is mining activity. Geodetic monitoring of deformations and displacements caused by mining activities is of key importance for ensuring the safety of people's activities on the surface. To perform geodetic surveys, the establishment and maintenance of a local control network with reference stations of the highest accuracy is essential. The stability of the reference network should be constantly monitored and controlled to assessed the quality of the actual solutions of the reference stations and the reliability of the entire network.

The goal of this study is to perform the stability analysis of the GNSS permanent stations located at a mining area where significant mining activity is observed. Daily coordinate solutions obtained from over 2 years of GNSS data processing performed in Bernese GNSS Software v.5.4 are collected and analyzed. The results show that the station coordinates are characterized by high stability over time. The standard deviation is below 2 mm for the horizontal components and below 3.5 mm for the height for all stations. The results also reveal a continuous movement of one station located near a mine shaft. In addition, a jump in the station coordinates was registered which was caused by a mining shock on the 7^th of April, 2022. As a results, the station moved 50 mm northwards, 48 mm in the eastwards and 88 mm downwards.