Spaceborne InSAR for Monitoring and Health Assessment of Historical Architectures: The Tianjin Case Study

Abstract Recently, interferometry synthetic aperture radar (InSAR) technology has shown its capabilities to monitor the displacement of natural processes with millimeter accuracy. Nevertheless, there is limited InSAR research on the health assessment of historical architectures. In this paper, we firstly proposed a possible methodology aiming at health assessment of historical architectures using space-borne SAR data. The proposed strategy consists of extracting building deformation from Persistent Scatterer Interferometry (PSI)results with spatial analysis between a geographical database and geocoded Persistent Scatterer (PS) and Inverse Distance Weighted (IDW) interpolation, deriving assessment parameters of both angular angle () and unequal subsidence velocity (), finally comparing them with alarm value for health assessment. This method has been applied to the Heping District of Tianjin (China), which contains many historical architectures, and two important examples (the Bohai Building and the China Theater) in the region were selected for detailed analysis, through the use of a high-resolution satellite dataset. For these two buildings, after extracting and analyzing deformation, both of the assessment parameters (and ) were acquired, and the good health conclusions were acquired in the case of values smaller than the alarm thresholds, which were validated by the similar conclusion from in situ leveling records. Finally, both the deformation mechanism of two architectures and health assessment ability with InSAR were analyzed in detail for further application.