DEFENSE ADVANCES RESEARCH PROJECTS
AGENCY ARTIST’S CONCEPT
have both active and passive
acoustic search, detection, passive-threat filtering, localization and
tracking capabilities. It also will
provide torpedo detection and alert
and avoidance of small objects.
Ed Hoak, program manager for
sonars at Raytheon Integrated
Defense Systems, said the sonar’s
“advanced transmit/receive front
end” is key to the performance of
the sensor and that it forms the
backbone of future acoustic sensors. The latest version of the sonar
has had the number of replaceable
parts reduced from 400 to 15.
The Anti-Submarine Warfare Continuous Trail Unmanned Vessel is being developed
as an autonomous unmanned surface vehicle that would track diesel-electric submarines for months at a time with minimal human input.
The main challenge of the
ACTUV sonar development is “
removing the man in the loop,” he said.
The ACTUV’s sonar will need to
be autonomous, performing the difficult task of subma-
rine tracking without an operator directing its operation.
It will need sophisticated algorithms for automatic track-
ing, including maintaining a low false-target detection
rate. The sonar also will help the ACTUV observe the
rules of safe navigation applicable to any vessel at sea.
The MS3 for the ACTUV has a “wet side” transducer
similar to the SQS- 56, but the “dry side” — the pro-
cessing electronics — is significantly smaller, with
fiber-optic lines replacing heavy copper cables.
Raytheon is under contract to build one sonar for
the ACTUV prototype.
DARPA completed the ACTUV’s Preliminary Design
Review in April and a software design review in May.
Phase 2 is ongoing and will culminate in a Critical
Design Review, scheduled for September. Phase 3, the
building of the craft, is scheduled to begin in January.
Phase 4, operational prototype at-sea testing, is expected to start in early 2015, Littlefield said.
DARPA assigned seven specific tasks to SAIC for the
program: system design and risk reduction; software
development; long lead-time material procurement;
system development and trials; software development
and documentation; vessel construction; and support
of at-sea government testing, operations, maintenance
DARPA is in discussions with the U.S. Navy regarding
transition of the ACTUV vessel and associated technology.
Chris Johnson, a spokesman for Naval Sea Systems
Command, said that the Navy’s Unmanned Maritime
Systems program office has “collaborated with DARPA
on their ACTUV efforts.”
SAIC did not respond to Seapower queries by press
time June 17. ■
forces total 54 SSNs and an MPA force of 14 active and
Reserve operational squadrons, with an eventual force
of approximately 100 new P-8A Poseidon aircraft.
Although the capabilities of the newest platforms
surpass those of older platforms, the reduced numbers
present a challenge in providing continuous surveillance of submarines of interest.
“DARPA envisions a platform that could operate from
any port,” Littlefield said. “DARPA plans to include nav-
igation and situational awareness sensors, including
radar, Automatic Identification Systems (AIS) and ASW
sensors. ACTUV would use commercial diesel engines
and operate at sea for at least 70 days at a time. ACTUV
is designed to remain mission-capable in Sea State 5 [8-
to 12-foot waves and wind speeds of 21 to 25 knots] and
survive in Sea State 7 [25- to 40-foot waves and wind
speeds of 37 to 46 knots].”
DARPA selected six industry proposals for the
ACTUV concept in January 2010 for Phase 1 of the pro-
gram, the concept definition phase. In August 2012,
DARPA selected Science Applications International
Corp. (SAIC) to design, construct and demonstrate an
ACTUV prototype under the next three phases of the
program under a $58 million contract.
SAIC “proposed a trimaran platform: key features
and innovations for the vessel, sensors, autonomy and
software. The scope of the program includes developing and testing a Remote Supervisory Control System,”
In March, Raytheon Co. announced that it had been
selected by SAIC to provide the sonar system for the
ACTUV. The Modular Scalable Sonar System (MS3), a
fifth-generation development of the company’s 30-year-
old medium-frequency, hull-mounted SQS- 56 sonar will