The DASH Program anti-submarine sensors - TRAPS & SHARK

A team from DARPA prepares to send its Submarine Hold at RisK (SHARK) unmanned underwater vehicle (UUV) on a mission to hunt submarines. Photo from DARPA/Bluefin Robots

The following draws on a WIRED - Danger Room article, April 3, 2013 http://www.wired.com/dangerroom/2013/04/darpa-subs/ and other sources.

Robots, Deep-Sea Sensors Help Pentagon Futurists Hunt Subs DARPA announced on April 3, 2013 that it’s successfully tested two methods of detecting quiet submarines under its Distributed Agile Submarine Hunting (DASH) research program. The methods are:

• Transformational Reliable Acoustic Path System (TRAPS) - a series of [presumably aircraft, ship or submarine] dropped-and-forget sonar devices. Each device is a fixed, passive sonar node, designed to sit on the sea floor (unlike existing sonobuoys that float) and communicate back to a floating “stationary surface node” through a wireless acoustic modem when something that sounds like a sub [or a surface ship? drug smugglers? pirates? etc] churns past. The idea is to trade sophistication for a distributed array of sensor packages that, once networked, will set up a vast, trap of sound detection. TRAPS may be viable if it is durable, inexpensive, the modems can handle the depths and no one hacks or spoofs the signals. There is no tech support under the waves. “This is a gamble,” DARPA program manager Andy Coon said in a prepared statement, “but we believe the potential payoff will be high" [see DARPA Press Release].” 

• Submarine Hold at RisK (SHARK) - a yellow unmanned underwater vehicle (UUV). Its torpedo shape indicates it is suitable for aircraft, ship or submarine deployment. Described by DARPA as a “mobile active sonar platform,” SHARK is supposed to track submarines once they’re initially detected, presumably by the TRAPs or current Integrated Undersea Surveillance System (IUSS) technologies - see diagram below) systems.  DARPA disclosed on April 3, 2013 that it took the SHARK to an unspecified depth in February 2013, which Andy Coon likened to “going to another planet.”

US Navy engineers have yet to figure out how to design a long-distance UUVs, as the propulsion and fueling systems necessary to get the things to span oceans aren’t thought to exist - short of nuclear power. Current thinking from the Navy holds that UUVs will launch from existing aircraft, subs and surface ships, supplementing the manned platforms through scouting and a wider communications network.

It’s unclear what range DARPA wants to provide SHARK. Speed is another factor particularly in shadowing fast SSNs not just slow SSKs. If DARPA can devise, cheap and durable ways of propulsion and efficient fuelling for long-range travel, it’ll usher in not just a new wave of sub-hunting, but a new wave of unmanned subs. And it’s worth noting that DARPA’s SHARK team includes Bluefin Robotics, which is spearheading some of the Navy’s most ambitious experiments with robotic submarines.

DASH isn’t DARPAs only anti-sub program. It is also working on a largely autonomous surface ship called the ACTUV, (see http://gentleseas.blogspot.com.au/2013/03/anti-submarine-drone-ship-actuv.html ) which DARPA wants to prowl the seas hunting subs with its advanced sonars for up to 90 days at a stretch. There’s some reason to suspect ACTUV may complement the DASH program. Defence giant SAIC is building both the SHARK UUV and the TRAPS.
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The US Navy network, known as the Integrated Undersea Surveillance System (IUSS) multi platform sensor network, may eventually incorporate TRAPS, SHARK and ACTUV technology.

For more information, dated year 2000, for the older systems FDS and ADS, see http://www.dote.osd.mil/pub/reports/FY2000/navy/00fds.html .

Federation of American Scientists 1996 info on Fixed Distributed System (FDS)  technology https://www.fas.org/irp/program/collect/fds.htm and 1998 info on Advanced Deployable System (ADS) http://www.fas.org/irp/program/collect/ads.htm
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COMMENT
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In addition to sound current IUSS may well include visual spectrum, night-vision, magnetic anomaly, active sonar, infrared sensors and pressure/ripple sensors. DASH technologies will upgrade some existing sensor capabilities.

Undersea sensors would be just one component/platform of a sensor network against submarines which would also include "spy" satellites, sigint ground stations, surface ships, SSKs, SSNs, aircraft and tracking information from allies. If a Chinese SSN entered the Indian Ocean all these sensors and alliances would watch and probably handover intensively.

The funneling dictated by the geography of the Strait of Malacca would assist in triggering or "scripting" the many sensor platforms available.

Link with the following on this "gentleseas" website

LIDAR an anti-submarine warfare sensor, January 16, 2014, http://gentleseas.blogspot.com.au/2014/01/lidar-anti-submarine-warfare-sensor.html

Anti Submarine Drone Ship (ACTUV), March 18, 2013, http://gentleseas.blogspot.com.au/2013/03/anti-submarine-drone-ship-actuv.html , and 

Satellite Detection of Submarines. April 11, 2012, http://gentleseas.blogspot.com.au/2012/08/satellite-detection-of-submarines.html

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Pete