Motion-compensated acoustic positioning in very shallow waters using spread-spectrum ultra-short baseline array processing

A motion-compensated ultra-short baseline acoustic positioning system operable in shallow water and port environment has been implemented at Florida Atlantic University. Multi-tones signal modulation and log-likelihood maximization enable this acoustic positioning system to operate in volumes of water of less than 10 cubic meters. The motion compensation system estimates the array position and orientation by merging inertial and differential GPS measurements using Kalman filtering techniques. Experiments show 0.67 and 2.67 degrees of error for the array tilt and heading estimates, and 0.74 meter for the array position estimate at a range of 23 meters.