Ambient Light Calibration of a Scanning Slope Sensor

摘要

This paper outlines a procedure developed to calibrate a laser-based watersurface slope sensor against ambient light variations. An analysis of the optical position sensor used in the system indicates how variations in the ambient light intensity cause shifts in the illumination pattern centroid calculated by the sensor electronics. These shifts are misinterpreted as slope variations of the water surface unless special calibration measures are performed. The analysis is also used to illustrate a technique to compensate for this effect. The analysis is validated using laboratory and field data, and the calibration technique is then applied to data recently collected in the North Atlantic during the joint ONR/NRL HIRES program.