Modal Imaging of Portsmouth, New Hampshire Bridge for Video- Based Structural Health Monitoring

We compare the results of modal imaging [1], a method for measuring operational deflection mode shapes and frequencies in video, to the predictions of a finite element simulation, as well as accelerometer measurements, of a Portsmouth, New Hampshire bridge. The finite element simulation is based on schematics obtained from the New Hampshire Department of Transportation. We also compare the results of modal imaging on the bridge to previous visual analysis from [2], and discuss some of the algorithmic differences that appear to improve results.