Urban Subsidence Monitoring Using Radar Interferometry

Abstract

The differential interferometric SAR (DInSAR) technique has proved its capability to detect small surface deformations in several types of applications. In this paper, its use as a quantitative subsidence monitoring tool is addressed to. A complete procedure is described, giving emphasis to the algorithms that have a major impact on the quality of the DInSAR results: the calibration of the InSAR geometry based on ground control points, which guarantees a high accuracy of the InSAR geometric model; a filtering procedure suitable to reduce the atmospheric effects in small-scale subsidences; and a data fusion procedure for multiple observations, which represents a key step to improve the quality of the DInSAR products. The procedure was used in the analysis of a small-scale urban subsidence located in Catalonia, northeastern Spain. The validation of the results, which was based on the comparison with precise and independent reference data, is discussed in detail.