Directional Acoustic Transponder

The focus of this program is on the development and integration of twocomplementary technologies designed to provide a single point referenceenabling undersea unmanned vehicles (UUVs) autonomously to obtain theirrange, bearing, and perhaps, geoposition. Each of the technologies isbased on an extensive history of development and application, although theintegration of the two is unique. Our approach involves broadband acousticcommunications (acomms) to provide range estimation and carry data, andsmall multi-element receivers for bearing estimation. The proposed systemplaces no burden on the UUV, beyond simply supporting a modem and a compass. The developments proposed here will provide an alternative navigation system for UUVs and divers without the expense, effort, and observability required to establish a conventional LBL navigation system. It will permit inexpensive UUVs and ROVs tomaintain a combined navigation and communications link with command. The techniques proposed are amenable to enhancement, especially with regard to integration with spatially distributed arrays and the increased directivity obtainable thereby. Two ormore units can easily be linked into a self-configuring network to provide both redundancy and performance improvement for navigation.