EVALUATION OF THE MONITORING OF SURFACE DEFORMATIONS IN OPEN-PIT MINES WITH SENTINEL-1A SATELLITE RADAR DATA

Abstract

Accidents and loss of life can occur in surface mines due to large mass displacements (landslides). In order to prevent these irreversible situations, it is very important to identify displacements in advance or to take necessary measures by obtaining early warning signs. Within the scope of this study, satellite radar images (SAR, Synthetic Aperture Radar) obtained from the European Space Agency (ESA) Sentinel-1A satellite were used to reveal the traceability and monitoring sensitivity of deformations and possible mass displacements in the dump area of a mining operation. The results obtained from 2 Global Positioning Systems (GPS) installed in the field were compared with the results obtained from satellite radar data and their compatibility with each other was evaluated. When the horizontal/vertical velocity values obtained by decomposing the Sentinel-1A ascending and descending satellite line of sight (LOS, Line Of Sight) velocities were compared with the horizontal/vertical velocity values of GPS, the results were statistically equal. GPS-based vertical velocities were -131.5 mm/year at GPS1 and -20.7 mm/year at GPS2, while Sentinel-1A-based velocities were -94.5 mm/year at GPS1 and -7.8 mm/year at GPS2. While both GPS and satellitebased vertical deformations show the same direction (in the form of subsidence), the deformation velocity values obtained from satellite radar data are lower than GPS results. Horizontal deformations obtained with satellite radar data could not be determined in the north/south direction due to satellite orbital motions, while they could be partially determined in the east/west direction. GPS-based east/west horizontal velocities were +2.8 mm/year in GPS1 and unsignificant velocity was found in GPS2. Satellite-based east/west horizontal velocity values were +6.8 mm/year at GPS1 and +8.4 mm/year at GPS2.