Integration of GPS, Accelerometer and Optical Fibre Sensors for Structural Deformation Monitoring

An integrated system comprising GPS, accelerometer, and optical fibre sensors has been proposed to monitor structural deformation in order to assess the integrity of the structure. The GPS and accelerometer sensors have been installed on a 108m tall steel tower, and data have been collected during Typhoon No. 21 on 1 October 2002, at 10Hz and 20Hz rates respectively. The wind induced deformation has been analysed in both time and frequency domains. In the frequency domain, both the GPS and accelerometer results show strong peaks at 0.57Hz, although GPS measurements are noisy in the low frequency end. On the other hand, the result of a series of indoor experiments shows that the optical fibre Bragg grating (FBG) sensors have demonstrated excellent performance with respect to sensitivity, linearity, repeatability and dynamic range.