Structural displacement monitoring remains a challenging problem, especially for long-span bridges. A ground-based microwave interferometric radar system was developed and used to obtain multipoint displacement measurements of a suspension bridge with a main span of 1200 m. First, a microwave interferometric radar system with the merits of low price, straightforward usage, and good stability and robustness was developed. The phase was obtained by performing fast Fourier transform (FFT) of the in-phase/quadrature signals and calculating the displacement according to the phase interference. Second, the radar system was used in field tests of a long-span suspension bridge, including static, ambient vibration, and moving load tests. Multipoint displacements of the bridge girder, tower, and cables were obtained, and simultaneous measurements of the multipoint displacement influence lines of the bridge girder were performed. A method that uses three reference points to measure the bridge girder displacement was proposed. Good agreements between the results from the developed radar system and those from traditional sensors, including connecting pipes and total stations, demonstrated the excellent performance of the proposed method for remote multipoint displacement measurements of long-span bridges.

结构位移监测仍然是一个具有挑战性的问题，特别是对于大跨度桥梁。开发了一种地面微波干涉雷达系统，该系统用于获得主跨为1200 m的悬​​索桥的多点位移测量。首先，开发了价格低廉，使用简便，稳定性和鲁棒性强的微波干涉雷达系统。通过对同相/正交信号执行快速傅里叶变换（FFT）并根据相位干扰计算位移来获得相位。其次，该雷达系统用于大跨度悬索桥的现场测试，包括静态，环境振动和移动载荷测试。获得了桥梁，塔架和电缆的多点位移，并同时测量了桥梁的多点位移影响线。提出了一种使用三个参考点来测量桥梁位移的方法。发达雷达系统的结果与传统传感器（包括连接管道和全站仪）的结果之间达成了良好的协议，证明了该方法在大跨度桥梁远程多点位移测量中的出色性能。