Measurement of Bridge Dynamic Responses Using Network-Based Real-Time Kinematic GNSS Technique

The network-based real-time kinematic (NRTK) global navigation satellite system (GNSS) technique was proposed for the first time to monitor the dynamic response of bridges. It could receive corrections from an established remote continuously operating reference station (CORS) network instead of a user-defined local reference station. To validate the feasibility of the NRTK-GNSS technique, laboratory and field experiments were both conducted at the University of Nottingham, U.K., and the Wilford suspension bridge, a footbridge close to the university's campus. The conventional real-time kinematic (RTK)-GNSS and accelerometer techniques were synchronously considered for validating the accuracy of the NRTK-GNSS technique. A wavelet packet filtering scheme was designed to process full-scale experimental data according to the characteristics of NRTK-GNSS measurement noise. The dynamic displacements and vibration frequencies of the bridge were successfully identified from the NRTK-GNSS data with satisfactory accuracy. In conclusion, the study confirms that the proposed NRTK-GNSS can be a potential technique for the dynamic monitoring of bridges, with adequate performance and lower operational cost. It will be a powerful monitoring tool for structural health monitoring with continuous enhancement in the hardware and algorithm.