Raytheon's 5th generation hull mounted sonar to enable anti-submarine, undersea warfare

Raytheon was awarded a sub-contract from Science Applications International Corporation (SAIC) to deliver its first 5th generation medium frequency hull mounted sonar system as part of the Defense Advanced Research Projects Agency (DARPA) Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) program.
According to the U.S. Navy, 43 nations operate more than 600 submarines; the steady increase in undersea vessels makes tracking a challenge.
Raytheon's Modular Scalable Sonar System (MS³) will integrate into SAIC's prototype trimaran vessel as the primary search and detection sonar. The system is designed to provide search, detection, passive-threat filtering, localization and tracking capabilities without requiring human operation.
MS³ enables anti-submarine warfare (ASW) and undersea warfare with capabilities such as active and passive search, torpedo detection and alertness, and small object avoidance.
Data from multiple sonars may be fed to a central command and control node, providing a common operating picture as part of the ASW mission. By integrating a host of capabilities in a single sonar system, Raytheon delivers an affordable solution that addresses critical naval challenges. 
"Historically, manned sonars were central to anti-submarine warfare missions. However, the growing number of submarines traversing the world's oceans makes this model unsustainable," said Joe Biondi, vice president of Advanced Technology for Raytheon's Integrated Defense Systems business. "By leveraging Raytheon's heritage in developing undersea sensors, MS³ can be configured to provide the capabilities required for ASW in an autonomous environment."
The Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) is developing an unmanned vessel optimized to robustly track quiet diesel electric submarines. The program is structured around three primary goals:

• Explore the performance potential of a surface platform conceived from concept to field demonstration under the premise that a human is never intended to step aboard at any point in its operating cycle.  As a result, a new design paradigm emerges with reduced constraints on conventional naval architecture elements such as layout, accessibility, crew support systems, reserve buoyancy and dynamic stability.  The objective is to generate a vessel design that exceeds state-of-the art platform performance to provide complete propulsive overmatch against diesel electric submarines at a fraction of their size and cost.
   
• Advance unmanned maritime system autonomy to enable independently deploying systems capable of missions spanning thousands of kilometers of range and months of endurance under a sparse remote supervisory control model.  This includes autonomous compliance with maritime laws and conventions for safe navigation, autonomous system management for operational reliability, and autonomous interactions with an intelligent adversary.
   
• Demonstrate the capability of the ACTUV system to use its unique characteristics to employ non-conventional sensor technologies that achieve robust continuous track of the quietest submarine targets over their entire operating envelope.

While the ACTUV program is focused on demonstrating the ASW tracking capability in this configuration, the core platform and autonomy technologies are broadly extendable to underpin a wide range of missions and configurations for future unmanned naval vessels.
The program has four phases. During phase 1, the program refined and validated the system concept and associated performance metrics, completing risk reduction testing to inform program risks associated with submarine tracking sensors and maritime autonomy. In August 2012, DARPA awarded a contract for phases 2-4.  The program plans the following in upcoming phases: Design a vessel (Phase 2); Build a vessel (Phase 3) and test the vessel (Phase 4). Operational prototype at-sea testing is expected in mid-2015.