Novel Sensing and Detection

With the blue water threat of free-ranging, nuclear-armed Soviet submarines coming to a head in 1971, the DoD assigned DARPA a singular mission: Revamp the U.S. military’s antisubmarine warfare (ASW) capabilities to track enemy subs under the open ocean where the U.S. Navy’s existing Sound Surveillance System (SOSUS) was falling short.

Today, cost and complexity limit the Navy to fewer weapons systems and platforms, so resources are strained to operate over vast maritime areas. Unmanned systems and sensors are commonly envisioned to fill coverage gaps and deliver action at a distance. However, for all of the advances in sensing, autonomy, and unmanned platforms in recent years, the usefulness of such technology becomes academic when faced with the question, “How do you get the systems there?” DARPA’s Upward Falling Payloads program seeks to address that challenge.

DARPA’s Distributed Agile Submarine Hunting (DASH) Program has tested two complementary prototype systems as part of its Phase 2 development effort. The prototypes demonstrated functional sonar, communications and mobility at deep depths. The successful tests furthered DASH’s goals to apply advances in deep-ocean distributed sonar to help find and track quiet submarines.

Cost and complexity limit the number of ships and weapon systems the Navy can support in forward operating areas. A natural response is to offset these costs and risks with unmanned and distributed systems. But how do such systems get there in the first place?

DARPA’s Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program seeks to develop a new type of unmanned surface vessel that could independently track adversaries’ ultra-quiet diesel-electric submarines over thousands of miles. One of the challenges that the ACTUV program is addressing is development of autonomous behaviors for complying with the International Regulations for Preventing Collisions at Sea, known as COLREGS. Substantial progress has been made in developing and implementing those behaviors.