Measurement of wind-induced response of buildings using RTK-GPS

Accelerometers have been used for field measurements of wind-induced responses of buildings. However, wind-induced response consists of a static component, i.e. a mean value, and a dynamic fluctuating component. The static component is difficult to measure by accelerometers. An RTK-GPS (Leica MC1000) has a nominal accuracy of71 cm +1 ppm for horizontal displacements and 72cm +2ppm for vertical displacements with a sampling rate of 10Hz. This study aims to demonstrate the feasibility of RTK-GPS for wind-induced response measurements and its efficiency in measuring the displacement of a full-scale tower. As the first experiment, the accuracy of Real-Time Kinematic-Global Positioning System (RTK-GPS) in measuring sinusoidal displacements was examined, using an electronic exciter. When the vibration frequency was lower than 2Hz and the vibration amplitude was larger than 2 cm, RTK-GPS results seemed to closely follow the actual displacement. The efficiency of RTK-GPS was then demonstrated in the full-scale measurement of an actual steel tower. Based on the feasibility study of RTK-GPS for measuring wind-induced responses of buildings, the responses with amplitudes larger than 2 cm and natural frequencies lower than 2Hz can be detected by RTK-GPS