Simulated 3D slope stability monitoring using InSAR enabled by the MDA CHORUS synthetic aperture radar constellation

Authors: Hickson, D; Oliver, P; Morin, R Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2535_51

Cite As:
Hickson, D, Oliver, P & Morin, R 2025, 'Simulated 3D slope stability monitoring using InSAR enabled by the MDA CHORUS synthetic aperture radar constellation', in JJ Potter & J Wesseloo (eds), SSIM 2025: Fourth International Slope Stability in Mining Conference, Australian Centre for Geomechanics, Perth, https://doi.org/10.36487/ACG_repo/2535_51



Abstract:
Satellite synthetic aperture radar (SAR) observations are crucial for an effective ground stability monitoring program in mining operations. Interferometric processing can provide millimetre-precision time series measurements of ground displacement at high resolution over wide areas, regardless of time of day or weather conditions. However, if the direction of ground displacement is not aligned with the line-of-sight (LOS) between the satellite and target, the measurements will be significantly underestimated. Furthermore, the side-looking imaging geometry of these satellites introduces imaging distortions, such as layover and shadow, that also depend on the LOS and surface topography. These limitations on the quality of interferometric measurements are significant over mining sites with complex topographies and dynamic ground movement. These disadvantages can be partially overcome by incorporating multiple imaging geometries into the monitoring plan; however, given that most SAR satellites are sun-synchronous orbiting (SSO), a nearly polar orbit, this only improves sensitivity to east–west components of ground motion, leaving any north–south components poorly constrained. MDA Space will soon be offering MDA CHORUS, a next-generation dual-frequency C- and X-band SAR satellite constellation which will operate in an innovative mid-inclination orbit that provides access to new imaging geometries for interferometric processing. These unique LOS vectors will increase the measurement coverage in areas with variable topography and enable 3D ground displacement measurements with high precision in all directions, including the north–south component. In this work we present simulations of InSAR processing for 3D ground displacement monitoring at the BetzePost open pit at the Goldstrike mine in Nevada, USA. For the open pit we show how measurements by CHORUS increase the density of reliable measurements for a better characterisation of ground motion. For various multi-sensor combinations of CHORUS with SSO SAR sensors, such as CHORUS and RADARSAT-2, we simulate the precision attainable in 3D ground displacement measurements.

Keywords: slope stability, subsidence, geotechnical risk, remote sensing, InSAR

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