Monitoring slope stability and ground movement in and around Open Pits using
Advanced InSAR techniques.
Authors: Adrian Bohane, Giacomo Falorni, Fabrizio Novali
TRE Canada
Suite 410
475 West Georgia Street
Vancouver
BC
V6B 4M9
Tel 604 331 2512
www.trecanada.com
Abstract:
InSAR is a remote sensing technique that can be used in several different types and stages of mining.
The technique has developed rapidly in recent years and the most evolved algorithms are now capable of
providing a high spatial density of precise ground movement measurements over large areas.
The most advanced techniques process a large number of satellite radar images to determine
displacement of natural or man-made targets. The use of multiple images allows sophisticated statistical
calculations to model atmospheric noise, which can then be removed from the displacement
measurements, increasing accuracy to the millimetre level. SqueeSAR™, the most recent algorithm
produced by TRE, can also capture signals from spatially distributed targets, greatly increasing the
density of measurement points in rural areas.
In the case of open pit mines the technique can be used to monitor the stability of the surface area
around the pit, providing details on ground stability, deformation rates, active fault locations and
movement distribution, all information that can be used to guide the development of the mine pit. The
stability of the open pit slopes can also be measured, with an advanced technique that allows the
decomposition of the east/west and vertical components of motion.
The resultant movement can be tracked and reported on a weekly or monthly basis.
Examples of ground deformation data related to a large copper mine in the Thompson region of BC and
from Chile will be shown.
For sub-surface mining the technique is used to measure ground subsidence above the mine shafts and
in the surrounding areas. Examples from Rock Springs, Wyoming, will be shown in which SqueeSAR™
was used to identify and delineate subsidence troughs and to guide remediation activities. In this area a
density of 17,600 measurement points per square km was achieved, allowing the ground deformation
pattern to be mapped with minute detail.
Further applications of the technique are post-closure monitoring of mining sites, monitoring of tailing
pond dams and the monitoring of waste pile stability.
InSAR has a number of characteristics that make it a unique technique:

It normally does not require installation of ground instrumentation, making it non-intrusive.

It provides a high density of precise measurements over areas that can range from small to
extremely large (thousands of square kilometres).
Already well-established in the fields of Oil & Gas, landslide monitoring, transportation and groundwater
management it has only recently started becoming used in the mining industry.