Holographic navigation

This paper presents a method for navigating relative to the sea floor using sonar imagery. The aspect dependent terrain recognition problem is addressed by generating acoustic holograms of the sea floor containing images of all aspects of interest. Grazing angle compensation is applied to reduce the required spatial sampling from planar to linear. Sonar images are coherently correlated with centimeter resolution to provide navigational updates. The technique is demonstrated using five short duration missions in St. Andrew Bay and three long duration missions, with a combined extent of 69.7 km, in the Gulf of Mexico.