Dynamic Bridge Monitoring with Remote Sensing Techniques

Dynamic monitoring of bridges is usually performed with mounted sensors on the structure. Typically used technologies are accelerometers, electric strain gauges or fibre bragg grating sensors. All of them have the drawback that access to the structures is needed. This usually results in bridge closures during installation or during the measurement campaign. Furthermore, every measurement position has to be equipped with a separate sensor. We explore an alternative approach where the dynamic bridge behavior is determined with remote sensing techniques. Profile based terrestrial laser scanning as well as interferometric radar measurements enable the contactless measurement of bridge profiles with measurement rates of up to several hundred Hertz. Furthermore, dynamic 3D displacements can be determined with robotic total stations and GNSS receivers. This article thus discusses the state-of-the art of dynamic remote sensing techniques and in addition investigates the spatial and frequency resolution in real world examples.