NAVIGATION SYSTEM FOR AUTONOMOUS UNDERWATER VEHICLE BASED ON COHERENCE MAP

摘要

A method and system for facilitating navigation of an autonomous underwater vehicle (AUV) about an egress path that mirrors an ingress path. Complex return data during an ingress cycle are obtained and a corresponding complex image of the seabed along the ingress cycle is generated. Complex return data during an egress cycle are also obtained and a plurality of corresponding complex local images of the seabed along the egress cycle can be generated. The complex local images are compared to the complex ingress image to identify a normalized cross-correlation coefficient (NCCC). A maximum NCCC indicates that a position of the AUV in the along-track direction has been found. Successive local complex images from the egress cycle can be compared against the complex image from the ingress cycle as the AUV moves along the egress path to identify successive NCCCs, and monitored overtime to determine if the successive NCCCs are increasing or decreasing as the AUV moves along the egress path. The path of the AUV can be corrected to mirror the egress path to the ingress path based on the change of the NCCCs as compared to maximum NCCC.