Environmentally Adaptive Arctic navigation Signal Processing Navy STTR FY2012.A Sol No.: Navy STTR FY2012.A Topic No.: N12A-T016 Topic Title: Environmentally Adaptive Arctic navigation Signal Processing Proposal No.: N12A-016-0089 Firm: Ocean Acoustical Services and Instrumentation Syst 5 Militia Drive Lexington, Massachusetts 02421 Contact: Kevin Heaney Phone: (703) 346-3676 Web Site: oasislex.com Abstract: The proposed work will focus on combined signal processing and acoustic modeling that will ultimately enable high-accuracy navigation under the Arctic ice at ranges up to and including basin scale. This combined approach is required because as the source-vehicle range increases, the bandwidth of the signals decrease because the carrier frequency must be reduced to enable long-distance communications. The multipath spread and complexity of the signal also increase with range. The aim of the proposed work is to utilize as much of the received wave front information as possible in an effort to improve the range estimate and thus the localization accuracy. The effects of signal scatter off of the sea ice and limited a-priori sound-speed data will be addressed. Automated approaches for processing on-board the platform will be explored. The work builds upon and will extend that being done by WHOI for the ONR Marginal Ice Zone DRI, which will enable Sea Glider navigation to order 1 km and low-rate (several bps) communications. High-resolution acoustic propagation modeling, combining climatic and in-situ data, is essential in order to increase the accuracy and extent by more than an order of magnitude. Benefits: With a predicted increase in the amount of ice-free navigation time that will be available each year in the Arctic, a significant increase in commercial and military interest in this area is anticipated. To support these developments, a means for surveying seafloor and mid-water column properties will be required. To date, however, ice cover still prohibits surface ship operations for much of the year, making traditional ship-based surveys problematic. As a result, unmanned undersea vehicles (UUVs) present themselves as an optimal platform for performing large-scale surveys in this complex environment. A fleet of UUV-based surveying platforms can only be deployed if a robust under-ice navigation system is developed. This STTR proposal addresses several of the enabling technologies that will be required in order for that to happen. Return