Real-Time and Near Real-Time Displacement Monitoring With GNSS Observations in the Mining Activity Areas
Damian Tondaś, Kamil Kaźmierski, Jan Kapłon
Abstract
Ground deformations can be determined via various measurement methods, such as levelling, laser scanning, satellite navigation systems, synthetic aperture radar, and many others. In this paper, the authors present cross-validation displacement monitoring results obtained via real-time (RT) and near real-time (NRT) GNSS (Global Navigation Satellite System) calculation scenarios. To verify and validate the quality of RT and NRT long-term displacements, an independent post-processing (P-P) service was established. The study area was located in the Upper Silesian coal mining region in Poland. The verification procedure for the RT and NRT systems included a demonstration of the achieved accuracy, the time span required to detect a significant displacement, and the determination of the minimum detectable value of deformation. Regarding the P-P data source, the NRT service had RMS errors of approximately 2 and 4 mm for the horizontal components, while the RT errors ranged from 5 to 10 mm. In the vertical direction, the NRT strategy had RMS errors of 5-6 mm, while the RT service achieved the accuracy of 10 mm. The minimum detectable values of deformation for the NRT procedure were 5, 7, and 11 mm in the northern, eastern, and up directions, respectively. For the RT system, the significant values were determined to be 10 and 15 mm for the horizontal and 20 mm for the vertical components.