A simple underwater video system for laser tracking

This paper presents a video system for underwater range finding and target tracking. The method depends on geometrical triangulation using a video camera, a laser diode, and an object plane. This system, which is completely controlled by a personal computer, provides excellent capabilities of efficient calibration and accurate range data processing. Through the calculation of the intensity center of the laser spot, we refine the performance of measurement up to subpixel accuracy. This system employs polynomial interpolation to calibrate the measurement error resulting from geometrical distortion and lens aberrations. The results show that the system can produce excellent accuracy for range finding and target tracking both in air and underwater.