Review of electromagnetic waves-based distance measurement technologies for remote monitoring of civil engineering structures

Abstract

Measuring distance is essential for health monitoring and condition assessment of civil engineering structures. This paper reviews recent advances in remote sensing technologies for measuring distance based on electromagnetic waves. Specifically, four families of technologies are reviewed, which are the Global Navigation Satellite Systems, microwave radars, laser-based methods, and vision-based methods. The reviewed content covers the measurement principles, signal processing methods, state-of-the-art applications, and key performance metrics. The investigated performance includes the measurement accuracy, sampling frequency, operating distance, robustness to the environment, and compatibility with autonomous platforms. Existing inconsistent viewpoints concerning the performance are discussed. Based on the features of different technologies, a decision tree is presented to facilitate selection of appropriate methods for intended applications. This research is expected to promote development and applications of remote sensing technologies for facilitating condition assessment of engineering structures.