Integrated Space Geodetic Techniques for Monitoring Ground Subsidence Due to Underground Mining

Ground subsidence monitoring is of paramount importance in relation to the safety and efficiency of underground mining operations. Moreover, in established coal fields in eastern Australia, it has become harder and harder to select underground minesites which can avoid major engineering structures both on the surface and underground (highways, bridges, buildings, abandoned workings of old underground mines, and so on). Therefore, monitoring of mining operations via the integration of several geodetic techniques is important for the safety of the major engineering structures in the mine environment. However, the current subsidence monitoring techniques are both time-consuming and costly. In this paper, two schemes, namely, the integration of the Continuously-operating GPS (CGPS) receiver networks and Interferometric Synthetic Aperture Radar (InSAR) (the so-called ‘soft densification’ option), and the integration of singleand dual-frequency GPS receivers (the so-called ‘hard densification’ option), are proposed to address the applications of ground subsidence monitoring. Experiments at the Tower Colliery near Sydney, Australia, will be described.