Concurrent mapping and localization and map matching on autonomous underwater vehicles

Concerns autonomous underwater vehicle (AUV) navigation by concurrent mapping and localization (CAM). This technique, which has roots in the robotics community, endeavors to build a map of a vehicle's environment by extracting information from objects within it while concurrently using that map to position the vehicle. As presented in this paper, CML relies on accurate vehicle attitude information and target tracking to retard the positional error growth rate. Map matching is an independent, but complementary process to CML. Map matching requires good short-term navigation for the creation of a small, local map. The location of this local map is then identified within a larger reference map, providing a periodic positional reset. The a priori reference map may have been created completely in a previous mission, or earlier in the current mission at a time when the positional uncertainty was comparatively small.