Satellite imagery able to detect surface deformation caused by mining

29th January 2014 By: Natalie Greve - Creamer Media Contributing Editor Online

Satellite imagery able to detect surface deformation caused by mining

Photo by: Bloomberg

JOHANNESBURG (miningweekly.com) – University of Cape Town (UCT) PhD graduate Dr Jeanine Engelbrecht has asserted in her thesis that microwave imagery captured from earth-orbiting satellites is able to measure deformation caused by underground mining.

“Surface deformation owing to underground mining poses risks to health and safety as well as infrastructure and the environment. The information, derived from the analysis of microwave data, will be useful for long-term monitoring efforts to guide future development planning and subsidence risk assessment,” she commented.

According to Engelbrecht’s research, satellite-based sensors could be used for remote detection and the monitoring of surface subsidence, contrasting with traditional field-based measurements, which were point-based and did not “understand” the full extent of deforming areas.

Added to this, monitoring large areas regularly was labour intensive.

To overcome these limitations, she used image data collected from earth-orbiting satellites to monitor millimetre- to centimetre-scale deformation at the earth’s surface.

Through the use of advanced signal-processing techniques, known as differential radar-interferometric techniques, Engelbrecht successfully measured and monitored surface subsidence that resulted from shallow underground mining activities. 

“The results suggest that, by using satellite data, large areas can be monitored remotely and the areal extent of deforming areas can be assessed, effectively overcoming the limitations of field-based techniques,” she said.  

Engelbrecht graduated from UCT’s Faculty of Engineering and the Build Environment last month.