Experimental utilization of interferometric radar techniques for structural monitoring

This paper presents a new surveying technique that can be employed with hardly reachable structures or extensive structures. The technique is based on an interferometric radar device, which can be positioned up to 2 km away from the structure to be examined and can record displacement measurements with a sampling frequency of up to 100 Hz and an accuracy of 0.1 mm. The results given by the radar are compared with those given by a set of three accelerometers on a test structure (namely, a steel cable-stayed footbridge) for three different loads: a symmetric dynamic load, an eccentric dynamic load and a symmetric quasi-static load.