Integration of GPS with accelerometer for measuring total displacement response of tall buildings

Accelerometer is a common sensor used to monitor displacement response of tall buildings under gust winds. Owing to the incapability of measuring static or quasi-static displacement response with accelerometers, Global Positioning System (GPS) has become an emerging sensor for measuring and monitoring both static and dynamic (termed total) displacement responses of tall buildings. However, the accuracy of total displacement measurement with GPS is affected by multipath signals. The current GPS is also incapable of accurately measuring high frequency displacement response. This study explores the possibility of integrating GPS signals with accelerometer signals to enhance the measurement accuracy of total displacement response of tall buildings. An interactive data processing procedure using both empirical mode decomposition (EMD) and adaptive filtering techniques is developed. In order to assess the effectiveness of the interactive processing method, a series of field measurement tests is performed on a site using a motion simulation table to generate various types of wind-induced dynamic displacement motions of a tall building in the pre-defined static position. In these tests, the GPS antenna and an accelerometer are installed on the same motion simulation table. The GPS and accelerometer data are processed with the interactive data processing method and are compared with the simulated motion. The test results show that the developed method can significantly enhance the measurement accuracy of total displacement response.