Global Laser Rangefinder Profilometry: Initial Test and Uncertainty Analysis

Abstract

Global Laser Rangefinder Profilometry (GLRP) is a novel optical technique for instantaneous measurement of complex three-dimensional surfaces. A functional GLRP system has been constructed in the Maneuvering and Seakeeping Basin (MASK) at the Naval Surface Warfare Center, Carderock Division (NSWCCD). The system is capable of measuring surface height displacements over 800 measurement points at 30 Hz. The MASK GLRP system was used to measure the surface profiles of large waves produced by wave-makers in the MASK and bow waves generated by a surface ship remote-controlled model (RCM). Several large wave measurements were performed at various wave heights and compared to sonic probe measurements. The large wave measurements were found to be consistent with sonic probe measurements to within 5%. The results from the large wave measurements and RCM model bow wave measurements are presented and discussed. Data was collected in calm water to quantify sources of error, including optical jitter. The random error of the GLRP system is estimated at approximately 1.6 mm. The purpose of this work was to test the ability of the GLRP system for use in tests commonly performed at NSWCCD.