Applicability of displacement measurements by microwave interferometry in bridge dynamics

Abstract

The terrestrial microwave interferometry is a rather new measuring technique, which allows the measurement of relative displacements of structures with an accuracy of up to 0.01 mm at a sampling rate of up to 4000 Hz, without any kind of instrumentation on the structure. Due to the high sampling frequency, capturing the vibrational behaviour of the measured object is also possible and thus its modal parameters can be directly determined. This paper presents briefly the measuring principle and some preliminary investigations performed to demonstrate the applicability of this measuring technique in structural dynamics of bridges.