Cameras as displacement sensors to get the dynamic motion of a bridge: performance evaluation against traditional approaches

Nowadays there is a strong interest towards new measurement techniques for structural health monitoring, especially related to bridges. The cost and complexity of any new measurement system are the main restraints or might constitute the reason for success. On the other side the performances of any new approach must be known and granted, accounting for facts like resolution, sensitivity, uncertainty. That is why recently a testing activity has been carried out on a bridge by comparing several state of the art approaches against traditional ones. Each of them had advantages and drawbacks if compared against the usual approaches; in this paper the use of cameras to monitor the bridge response during trains transit is being considered and some results will be presented.