Undersea Navigation System Under Development
The U.S. Defense Advanced Research Projects Agency (DARPA) is developing an undersea navigation system aimed at enhancing the U.S. Navy’s ability to provide precise, global positioning throughout the ocean basins.
A recently awarded contract to BAE Systems will support a program called the Positioning System for Deep Ocean Navigation (POSYDON), which seeks to allow undersea vehicles to accurately navigate while remaining below the ocean’s surface.
POSYDON aims to replace current navigational methods that pose a detection risk for undersea vehicles forced to surface periodically to access the space-based Global Positioning System (GPS), which cannot sufficiently penetrate seawater. Access to above-water GPS could also potentially be denied by hostile signal jamming.
Currently, submerged vessels use inertial measurement units and other dead-reckoning sensors to calculate their positions, DARPA said, but those sensors tend to provide accurate sole-source navigation only for short-term missions. On longer missions, vessels eventually have to surface to get a GPS reading, and in many situations, that surfacing can put them at risk.
A BAE Systems-led team will create a positioning, navigation and timing system designed to permit vehicles to remain underwater by using multiple, integrated, long-range acoustic sources at fixed locations around the oceans.
The vehicle instrumentation needed to capture and process acoustic signals for accurate navigation will also be developed under this program. Current state-of-the art inertial measurement units, Doppler velocity log systems and other underwater navigational sensors have significant cost and power requirements, which the agency is aiming to lower with the new program.
U.S. Defense Secretary Ash Carter has allocated $600 million over the next five years toward unmanned undersea technology development, including the POSYDON program. Other members of the POSYDON team are the University of Washington, the Massachusetts Institute of Technology and the University of Texas at Austin.
The technology is currently being prototyped, and the project is expected to take four years to complete. DARPA intends the system to serve autonomous underwater vehicles, although it will accept proposals for systems that could be used by other undersea vessels.
“BAE Systems has more than 40 years of experience developing underwater active and passive acoustic systems,” said Joshua Niedzwiecki, director of Sensor Processing and Exploitation at BAE Systems. “We’ll use this same technology to revolutionize undersea navigation for the POSYDON program, by selecting and demonstrating acoustic underwater GPS sources and corresponding small-form factor receivers.”