Reliability of InSAR satellite monitoring of buildings near inner city quay walls

Abstract

Amsterdam currently has a huge task of assessing and potentially upgrading its quay walls along the historic canals. Before replacement can take place, Amsterdam needs to determine the potential impact the replacement can have on the nearby buildings. The rate of vertical deformation of the adjacent buildings is used as indicator of potential foundation problems. To determine that rate, the current practice is to monitor the buildings by levelling for two years at least. This study shows that application of satellite measurements using Permanent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) could reduce the monitoring period to a few months. The paper describes the statistical procedure that has been applied to levelling and satellite measurements to verify their reliability and determine the rate of vertical deformation of the buildings. The procedure was applied in three case studies. The rates of deformation observed in the InSAR measurements are in good agreement with the rates of deformation observed in the levelling in two of the case studies. The locally optimized InSAR data set with observations in the period 2014-2019 provides an almost 100% coverage of reliable data points for all buildings in the case studies. More experience will need to be gained in the interpretation of InSAR measurements with respect to vulnerability of the buildings. Also, the procedure may be extended to include analysis of non-linear trends such as second order trends and seasonal effects.