Real-time monitoring rapid ground subsidence using GNSS and Vondrak filter

Human activities such as coal mining may cause rapid ground subsidence, which will damage severely on human-built structures such as coal transport railway or buildings, and even kill lives. In coal-mining areas, ground subsidence happens continuously, and its amplitude may be up to 10cm per day. In order to assure the safety of coal-mining areas, it's necessary to monitor the ground subsidence timely and precisely. This paper presents a continuously operating real-time global navigation satellite system ground subsidence monitoring system, which consists of hardware, data processing algorithms and software, communication link and peripheral equipment. A particular architecture was designed for field operation. For the data processing, the Vondrak filter is proposed to process the monitoring data. We operated the proposed monitoring system on the coal-mining area and verified the performance during the mining period from early July to December 2017. The monitoring results show that the proposed system has an accuracy of 5mm for ground subsidence monitoring on the basis of precise leveling data that were simultaneously observed. The proposed method can meet the accuracy requirement of ground subsidence monitoring, and it can provide continuous subsidence information in real time, which cannot be achieved by the traditional leveling surveying method. The monitoring system and data processing method can be applied to the monitoring of ground subsidence in subsidence area as well as geological disasters such as landslides.