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Virtual Reality Under the Sea.pdf
Virtual Reality Under the Sea
Virtual Reality
Under the Sea
USS Oklahoma City (SSN-723)
Shoots Torpedoes in the Bahamas
that Run in Newport
by Will Canto
“Firing Point Procedures, Sierra One, ADCAP torpedo, Tube 2,” barks Lieutenant Brian Roth, Officer of the
Deck on the USS Oklahoma City (SSN-723). He’s driven the ship to the optimum firing position against a live
target on the Atlantic Undersea Test and Evaluation Center (AUTEC) range in the Bahamas.
LTJG Wade Cole, the Junior Officer of the Deck (JOOD), directs final adjustments and announces, “Solution
“Ship Ready,” Roth confirms, properly continuing the litany prior to torpedo launch.
“Weapon Ready!” returns FT3(SS) Mike Brodbeck.
Satisfied all is well, Roth orders “Shoot on generated bearings.”
This is a familiar scene for many submariners, but today on Oklahoma City, there’s a difference. The
submarine is not launching an exercise torpedo, nor is its crew practicing only on the ship’s on-board test
equipment. Oklahoma City is plugged into a digital network established by engineers and scientists at the
Naval Undersea Warfare Center Division Newport (NUWCDIVNPT) that permits real-time connectivity among
submerged submarines on the AUTEC range and test facilities on the beach in the Bahamas and Newport,
Rhode Island. Oklahoma City, submerged in the Bahamas, has just launched a “virtual torpedo,” which runs
inside the “mind” of a computer – and whose guidance hardware is on a test stand – at NUWC’s Weapons
Analysis Facility (WAF) in Newport. After launch, the torpedo’s simulated location and corresponding wireguidance telemetry data are transmitted across the network between the WAF at Newport and the Oklahoma
City. The still submerged Oklahoma City “sees” the torpedo in real-time, thus allowing the generation of wire
guidance commands on board to compensate for target evasion.
Oklahoma City’s first test shot demonstrated the full capability of this system. Roth’s shot on Cole’s solution
was slightly off, but the team properly analyzed the torpedo run after launching, and FT Brodbeck inserted
steering commands to turn the weapon around, and acquire and hit the target. Roth’s watchsection
successfully launched two more “virtual torpedoes,” thus completing the first test period. LT Brent Rodgers had
the conn for the second series. His watchsection, guided by his JOOD, LTJG Chris Hoehn,
performed superbly, successfully launching five more virtual torpedoes, including a “Snapshot” – a rapid
torpedo firing in response to a close-aboard “enemy” contact.
Bringing Modeling and Simulation to the Fleet
This large-scale simulation project is called Synthetic Environment Tactical Integration, or SETI. It establishes
the systems, processes, and capabilities that give the Fleet access to NUWC’s models and simulations for
undersea warfare. SETI’s goals are to reduce cost and increase the value of testing and training through
synthetic torpedoes (as used by Oklahoma City), synthetic targets (to supplement live target services on
range), and integration of on-board trainers with external environments. With additional connectivity
enhancements, SETI will provide simulated targets, countermeasures, and range- correlated ocean
environments. Expected additions include simulations of undersea weapons for surface and air anti-submarine
platforms. The benefits of connecting NUWCDIVNPT’s undersea weapons simulations to live ASW platforms
Virtual Reality Under the Sea
Allowing crews to train on their own platforms, sensors, and fire control systems
Unlimited availability of virtual weapons
High confidence hit-or-miss assessment and analysis
Re-prosecution and re-attack support
Actual target evasion and weapon interaction with countermeasures
Avoiding some of the artificiality of exercise constraints
Thus, SETI expands the applications of high fidelity simulation capabilities far beyond the walls of the
laboratory, enhancing the reusability, accessibility, and versatility of these land-bound simulators. By coupling
an operational SSN to modeling and simulation assets, the Fleet can become an at-sea contributor to the life
cycle support of existing weapons and an integral part of research and development for new weapon
How it Works
For the SETI Virtual Torpedo program, submarines operating at depth and speed at AUTEC can constructively
launch virtual torpedoes that “run” at NUWC’s Weapons Analysis Facility in Newport, Rhode Island. The SETI
network integrates three major facilities into a single, coordinated system.
Atlantic Undersea Test and Evaluation Center (AUTEC)
The AUTEC range systems provide accurate underwater and in-air tracking for both firing platforms and
targets using a variety of acoustic beacons and sensors. By taking advantage of the growing maturity of
underwater acoustic telemetry, AUTEC can also provide two-way digital data communications with submarines
operating at speed and depth. Systems already under test have demonstrated reliable, secure, two-way data
transmission over several nautical miles at data rates exceeding one kilobit per second (Kbps). While this is
neither wide-band nor long range, it adequately supports the current requirement, and expected
advancements will bring higher data rates and longer ranges in the future.
Exercise Communication Center (ECC)
The ECC connects the simulation facilities at NUWC, Newport to the range infrastructure at AUTEC via
encrypted land line and satellite data links. It also provides a gateway to other high fidelity modeling and
simulation centers operated by the Army, Navy, and Air Force through similar classified communication links.
An OKLAHOMA CITY Officer of the Deck directs his watchsection
through the final stages of virtual torpedo launch.
Weapons Analysis Facility (WAF)
Virtual Reality Under the Sea
The actual Mk 48 ADCAP torpedo guidance and control hardware and its embedded software reside at the
WAF and constitute an OPTEVFOR-certified simulation. A nearby supercomputer simulates the torpedo-target
geometry and the underwater acoustic environment, and generates a high fidelity representation of what the
torpedo would “hear” at every moment of the evolving scenario. These acoustic inputs stimulate the torpedo
guidance system on the bench, which interprets the data and responds with steering commands. These, in
turn, are fed back to the computer simulation to move the scenario forward in time. Similarly, wire commands
from the submarine are received and acted upon also. This hardware-in-the-loop setup permits testing the
latest torpedo hardware and software more quickly, at lower cost, and with minimal risk. Further, it allows for
more rapid Fleet feedback and familiarization.
The Future
The SETI system design allows for extension of virtual reality to other instrumented ranges, such as Atlantic
Fleet Weapons Training Facility (AFWTF), Southern California Off-Shore Range (SCORE), and the Pacific
Missile Range Facility (PMRF). With additional development in acoustic telemetry, this capability could be
extended to open-ocean exercises.
Efforts are already underway to apply the already developed Mk 48 ADCAP virtual torpedo concept to airborne
platform lightweight torpedoes launched from aircraft, such as the Mk 46 and Mk 50. A partnership between
NUWCDIVNPT and the Naval Aviation Warfare Center Aircraft Division (NAWCAD) Patuxent River, Maryland,
is currently addressing the benefits of air-dropped virtual torpedoes.
The first test of this capability will have a live Light Airborne Multi-Purpose System (LAMPS) helicopter
launching virtual torpedoes against simulated targets. Deployed on surface ships, LAMPS helicopters perform
their mission by localizing submerged threats, downloading weapons presets into air-launched torpedoes, and
dropping the weapons to find and destroy the target. The scenario provides for real-time testing of probability
of kill, insertion of countermeasures by the threat, simulation of threat evasive maneuvers, and test of LAMPS
re-attack capabilities. This same technology can be applied to other air ASW assets, with substantial reuse of
our current capabilities for future platforms.
SETI is an example of how Navy support organizations are harnessing the electronics revolution to improve
the quality and flexibility of at-sea training, while reducing costs. It allows leveraging laboratory resources
created for long-term research and development to support other applications, such as training and readiness.
Continuing improvements in high performance computers allow engineers to simulate complex ocean
environments and predict sound-ray paths with ever greater accuracy. Advancements in communication
network architectures for simulation, such as DoD’s High Level Architecture (HLA), are supporting high-speed
transmission and integration of data from an array of platforms, sensors, and modeling and simulation devices.
Future developments in data processing and transmission, with improved human-computer interface, will
undoubtedly change the way sailors train to fight their ships and aircraft. Twenty-first century sailors are likely
to train more efficiently with the aid of virtual systems, allowing them to “stay-up” on their warfighting skills,
instead of “working-up” for deployments as we do today.
Will Canto is the project manager of the SETI system at NUWC, Newport.
Virtual Reality Under the Sea
Underwater Acoustic Telemetry
The SETI Virtual Torpedo Program makes use of a growing body of techniques for underwater acoustic digital
communications that have been under study for several decades in both academia and industry. Specifically,
AUTEC uses the NUWC-developed Underwater Digital Acoustic Telemetry (UDAT) modem system to provide
robust bi-directional communications between the facility’s Command/Control Center ashore and submerged
submarines on the range. At the transmitting end, a modem (modulator-demodulator) transforms digital data
streams into acoustic signaling waveforms that are transmitted through the water to a waiting receiver. There,
a second modem converts the acoustic signals back into digital data. On submarines at AUTEC, the incoming
acoustic telemetry signals are received on the WLR-9 sensors, while outgoing data is transmitted on the
broadband low frequency transducer that also serves as the standard range “pinger” for acoustic tracking.
Using acoustic signals with carrier frequencies between 10 and 20 kilohertz, data rates on the order of 900
-1800 bits per second are routinely achieved at 10,000 yards in deep water.
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