Over the past 10 years, slope monitoring radar via the interferometry technique has evolved as an important tool for safety-critical monitoring of pit wall movements in surface mining. While radar can provide near real-time high spatial resolution surface displacement movement, the displacement vector measured using interferometry is line-of- site (LOS) to the radar position and does not provide a spatially oriented vector.
Using two or more ground-based interferometric synthetic aperture radar (GBInSAR) systems to rapidly record continuous, spatially dense LOS displacement data of an open pit slope in ‘stereo’, has potential to provide detailed vector movement across an entire wall or whole pit. The radar displacement vectors can be combined to create a pseudo three-dimensional (3D) displacement map of the pit slope using millions of monitoring points. Data collected from several radar systems has potential to greatly improve the understanding of the 3D kinematics of a large rock slope and further assist in better mine planning and design, thus allowing more efficient mine operations. This paper will cover examples and analysis of pseudo 3D displacement map data from GBInSAR systems.
Ground-based interferometric radar (GBInRad) systems are a class of terrestrial remote sensing imaging systems, based on radar interferometric techniques (Monserrat, Crosetto, and Luzi. 2014; Caduff et al. 2015).
Interferometric radar imaging systems operate by emitting a phase-coherent signal in the microwave frequency band and then receiving the reflected arrival of the signal from the targets of interest. The basic principle of interferometry involves the comparison of two images, where the phase image from one measurement is subtracted from another one. The principal application of GBInRad systems is deformation monitoring, since the phase difference between the two radar images can be related to the displacement that occurred with respect to the line-of-site (LOS) (Tarchi, 1999, 2003; Reeves, 2000; Luzi, 2010; Farina et al,. 2011).