Simulation of the deep sea mosaicking process

The WHOI Deep Submergence Laboratory has bean investigating mosaicking of underwater imagery for many years, and successfully creating such mosaics on a production basis. The mosaics are at best an approximation of the true appearance of the underwater terrain, and their proper use requires understanding of the errors inherent in the mosaicking process. A simulation of the mosaicking process, from collection to production, has been developed. The simulation allows the variation of terrain type and roughness, sensor trajectory, tie-point collection scheme, and image reprojection. Strip mosaics formed from large numbers of images can be simulated. Random variations are introduced throughout. The simulated mosaics formed using standard techniques can be displayed visually and compared to a map made using rigorous techniques. Statistics involving tie point position errors are collected and presented. Results from the simulation are presented and explained. The simulation results are compared to real data from undersea vehicles. The results confirm the authors´ understanding of the major causes of mosaicking errors, allowing an understanding of how their current mosaics should and should not be used, as well as the fruitful direction of new developments in computer driven and aided mosaicking efforts