A Global Laser Rangefinder Profilometry System for the Measurement of Three Dimensional Wave Surfaces

A Global Laser Range Profilometry (GLRP) System has been developed at the Naval Surface Warfare Center, Carderock Division (NSWCCD) for the measurement of three dimensional wave surfaces. A laser diode array consisting of 100 diodes operating at 650nm with an energy output of 3.5 mW was used to illuminate the wave surface seeded with fluorescent dye at various points in the Miniature Water Basin (MWB) facility at NSWCCD. A CCD camera located above the water surface recorded successive images of the laser array at 30 frames per second. Image processing techniques were used to locate the centroid of the laser array diode locations in the collected images. Calibration images were taken at various calm water heights in order to convert the image centroid locations to real coordinates. Two- and three-dimensional results are presented, along with error analysis of the GLRP system and comparison to flow visualization. A discussion of possible applications and planned future work is also presented in this work.