Optimal Analysis of Seismic Response of a Tall Tower Monitored by an Integrated RTK-GPS System

Seismic response of a tall steel tower in Tokyo, Japan, has been monitored by an integrated RTK-GPS and accelerometer system and compared to results of finite element models (FEM) and frequency domain decomposition (FDD) method. The integrated results presented herein are consistent with FEM predicted values. Because of the inherent limitations of GPS and accelerometer when applied to civil structural monitoring, a solid reliability can only be realized through the multi-sensor integration. The integration enables system redundancy through information fusion by using digital signal processing techniques in the transformation of one form of measurement (e.g. displacement) to another (e.g. acceleration). Moreover, the newly developed algorithm for time-dominant frequency analysis presented in this paper supplies the frequency change information with respect to time. The findings have demonstrated the advantages of using high precision GPS sensor together with traditional accelerometer in civil structural monitoring under extreme loading conditions. The effectiveness of digital signal processing in optimal analysis of structural monitoring data from different sensors has been highlighted.