Bridge monitoring using BDS-RTK and GPS-RTK techniques

Global Navigation Satellite System (GNSS), especially Global Positioning System (GPS) technology has been employed to monitor large bridge deformation for more than 20 years. With the efforts of Chinese government and scholars, BeiDou regional navigation satellite system (BDS) has fully operated since December 27th, 2012, and the new-generation BeiDou-3 navigation satellites started to launch in 2015. That means BDS could be a new tool for the SHM (Structural Health Monitoring) of bridges. Hence, in this study, we will primarily focus on the promising performance of BDS system in the area of bridge monitoring. Firstly, the basic information of BDS satellites orbit was introduced. Then, the background noise and the ability to detect displacements of BDS were examined in an experimental platform. Thirdly, an experiment at the Baishazhou Yangtze River Bridge in China was carried out to assess the performance that BDS has compared with GPS. We found that the precision of BDS at static mode can achieve to 2-3 mm and 5-7 mm in horizontal and vertical component, and millimeter level displacements can also be detected by BDS measurements. With the real bridge monitoring data, BDS has a same or even better observation condition and data quality compared with GPS. It can also effectively identify the natural frequencies and movement statement of the bridge.