Submillimeter Accuracy of Multipass Corner Reflector Monitoring by PS Technique

This paper presents the results of an experiment that is performed with a network of bidirectional corner reflector (CR) multipass scattering equipment (MUSE), which enable 3-D-displacement measurements. We describe the results of an experiment which was designed to assess the precision of the measurements of ground displacement using MUSE CRs and the permanent scatterer (PS) technique. The CR displacements are applied by micrometric vernier controls during the acquisition of a TerraSAR-X time series of ten images. The relative displacements are estimated between each date, using a PS technique. This paper shows that the relative displacements between the reflectors are estimated with a precision of 0.48 mm along the line of sight. This precision is defined as the standard deviation of the difference between the measured and the applied displacements along the time series. The linear displacement rates of the reflectors are then estimated using the spatiotemporal unwrapping network algorithm, with a 0.4-mm/year precision. We finally show that the experimental results are well predicted by theorical simulations.