Differential Radar Interferometry for Mine Subsidence Monitoring

The history of mining disasters includes cases of subsidence and collapse into workings, and also a number of inrushes into underground mines, where deficiencies in surveying, or in maintenance and interpretation of plans, were prime factors. The most recent incident in Australia was at the Gretley Colliery in NSW, in 1996. The most recent such incident in the USA was at the Quecreek Mine in Somerset County, in 2002. There is one thing common between the two incidents: the mining surface was too close to the abandoned workings and nobody knew it. Is it possible to prevent such mining disasters by monitoring subsidence as the signature of mining activity using differential radar interferometry (DInSAR)? In this paper, it is proposed to use GPS to assist precise georeference and ensure sub-centimetre accuracy of InSAR results and GIS to interpret, archive, and deliver the subsidence data derived from InSAR. The procedure is being tested in Appin, southwest of Sydney, Australia.