Light detection and ranging (LiDAR) for measurement of coastal processes

An experimental study has been completed to investigate the ability of a low-cost, industrial 2D LiDAR instrument to obtain detailed measurements of time-varying free-surface elevation in both the laboratory and the field. When mounted above the swash zone of a sandy beach, the LiDAR instrument was able to make swash-surface measurements that compared well with concurrent measurements using an array of ultrasonic altimeters which have been shown to provide accurate point measurements. A significant advantage of using LiDAR technology is that a single instrument can be used to make measurements throughout the swash zone at a high spatial resolution O(10cm) that enables small scale O(10cm) flow features to be evaluated and is impractical using alternative point measurement devices. When mounted above a laboratory wave flume, the LiDAR instrument was shown to make measurements of the time-varying free-surface elevation along a section of the wave flume at a spatial resolution O(10mm) with comparable accuracy to an array of conventional capacitance wave probes. Thus using a laser scanner, a single instrument can be utilised to measure the entire wave field allowing detailed evaluation of wave transformation throughout the experimental domain.