Monitoring subsidence of waste piles and infrastructures of active open PIT iron mine in the Brazilian Amazon Region using SBAS interferometric technique and TerraSAR-X data

This paper presents the results of applying SBAS (Small Baseline Subset) differential interferometric technique using 33 Stripmap mode images from the TerraSAR-X satellite, over a 1-year monitoring, Stripmap mode, for detection of ground deformation processes in five Carajas open pit iron mines in the state of Pará/Brazil in Amazon region, characterized by torrential rains. The SBAS algorithm was used for the interferometric processing, with coherence threshold of 45%, 4 looks, Delaunay Minimum Cost Flow (MCF), with a reference GeoEye-1 DEM, which allowed obtaining a synoptic view of the mine complex, covering the infrastructure and benches, as well as detecting the deformation in one mine (N5W). In order to monitor the waste piles, a lower coherence value (30%) was necessary. The results obtained were consistent with field work data, including topographic surveying, showing that this technique can be very useful for ground movement alert, planning, and risk assessment.