LIDAR As A Laboratory Based Wave Measurement Tool

Abstract

Light detection and ranging (LIDAR) is a nonintrusive measurement technique commonly used in applications such as topographic mapping and architectural surveys. It relies on the time-of-flight of a laser pulse to measure the distance to a reflective surface. Work by Hwang et al. (2000) and Reineman et al. (2009) has identified the utility of using near-infrared scanning LIDAR systems to map sea surface elevation from airborne platforms. Terill and Fu (2008) have demonstrated the use of LIDAR from sea-based platforms such as FSF-1 Sea Fighter and R/V Athena. Work at NSWCCD has shown the LIDAR to be an effective tool in large-scale towing tank experiments as a non-intrusive spatial measurement of the free surface. This paper will present an overview of the operation of a LIDAR based measurement system in a laboratory setting using data from a series of experiments conducted at NSWCCD on Model 5673. Measurements from a range of Fn numbers based on the ship length and speed were made. Once the flow field around the transom sterned model was stationary, the LIDAR was traversed across the area of interest. This results in a 3-D map of the transom wake with an approximate nominal spatial resolution of 1.5 inches (3.8 cm) in either direction. Recommendations for future work and additional applications will also be discussed.