Multidimensional Data Analysis of Scanning Laser Doppler Vibrometer Measurements: An Application to the Diagnostics of Frescos at the US Capitol

A large-scale survey (∼700m) of frescoes and wall paintings was undertaken in the US Capitol Building in Washington, DC to identify regions that may need structural repair due to detachment, delamination, or other defects. A common approach for post-processing time series called Proper Orthogonal Decomposition, or POD, was adapted to frequency-domain data in order to extract the essential features of the structure. We present a POD analysis for one of these panels, pinpointing regions that have experienced severe substructural degradation.