Military Embedded Systems

Shipboard electronics trend both sophisticated and "retro"


September 06, 2017

Sally Cole

Senior Editor

Military Embedded Systems

As one of the world's most sophisticated scalable radar systems is poised to make its debut aboard U.S. Navy vessels, so is a "retro" version of an old approach to ship-to-ship communication. This old-style method enables sailors to use their vessels' signal lamps to text-message each other on handheld devices without knowing Morse code during communication-denied scenarios while at sea.

On the sophisticated end of advances in shipboard electronics, Raytheon’s AN/SPY-6(V) Air and Missile Defense Radar (AMDR) is a next-gen integrated air and ballistic missile defense radar designed to fill a critical capability gap for the U.S. Navy’s surface fleet.

Earlier this year, SPY-6(V) proved that it could search for, acquire, and track a ballistic missile test target during its first dedicated Ballistic Missile Defense exercise at the U.S. Navy’s Pacific Missile Range Facility in Kauai, Hawaii.

Its second test involved a more complex, threat-representative ballistic missile target than the earlier tests, in order to challenge both the detection and tracking capabilities of the new radar. SPY-6 acquired and maintained the long-range missile target track from launch through flight.

What exactly differentiates SPY-6(V) from most radar systems for military ships? “SPY-6(V) provides greater detection ranges, increased discrimination accuracy, higher reliability and sustainability, and lower total ownership cost, as well as a host of other advantages when compared to the current AN/SPY-1D(V) radar onboard today’s destroyers,” says Scott Spence, director of Naval Radar Systems for Raytheon.

It also happens to be an active electronically scanned array (AESA) S-band radar, which “provides more sensitivity and resources to cover more missions and more targets,” he adds.

Specifically designed for scalability, reliability, and ease of production, the SPY-6(V) relies on both innovative and proven technologies, including radar modular assemblies (RMAs), digital beamforming, and gallium nitride (GaN).

This is the first scalable radar built with RMAs, which are radar building blocks. “Each RMS is roughly 2 feet by 2 feet by 2 feet in size, and is a standalone radar that can be grouped to build any size radar aperture – from a single RMA to configurations larger than currently fielded radars,” Spence says.

The array size, or the number of RMAs needed, can be customized to the mission needs of a ship to provide it with the capability “to spot and defeat potential threats such as ballistic missiles, cruise missiles, airborne adversaries, surface threats, electronic threats, or any combination of them,” Spence notes. “Its cooling, power, command logic, and software are all scalable, which allows for new instantiations without significant radar development costs.”

Using a wideband digital beamforming radar “supports better target detection and discrimination,” he says. “Adaptive, wideband digital beamforming and radar signal/data processing functionality provides exceptional capability in adverse conditions, such as high clutter and jamming environments. It’s also reprogrammable to adapt to new missions or emerging threats.”

Commercial off-the-shelf (COTS) components and open architectures play an important role. The SPY-6(V) features a fully programmable, back-end radar controller unit built out of COTS x86 processors. “This programmability allows the system to adapt to emerging threats,” Spence says. “And the commercial nature of the x86 processors simplifies obsolescence replacement – as opposed to costly technical refreshes/upgrades and associated downtime – which are savings that lower radar sustainment costs during each ship’s service life. The radar’s open architecture also facilitates integration with existing and future combat-management systems.”

In terms of ballistic missile defense, the SPY-6(V) Air and Missile Defense Radar currently being developed for the U.S. Navy’s DDG 51 Flight III destroyer stacks 37 RMAs together to form a 14-foot-diameter octagonal array.

“The system consists of four of these arrays that will be installed in the ship’s deckhouse to provide 360-degree coverage for threat detection and response,” Spence says. “This configuration enhances the Navy’s ability to simultaneously detect, identify, and track any air, surface, and ballistic missile threats, delivering more than 30 times the sensitivity of the currently deployed SPY-1D radar. In other words: SPY-6 can simultaneously detect and track multiple targets of half the size at twice the distance of the radar it replaces.”

SPY-6(V) use

By providing greater capability – range, sensitivity, and discrimination accuracy – SPY-6(V) “increases battlespace situational awareness and reaction time to effectively counter current and future threats,” according to Spence. The radar enhances the ships’ ability to detect air and surface targets, as well as ever-proliferating ballistic missile threats.

Another key consideration, since ships are at sea for extended periods of time, is that reliability and maintainability are critical. “In most cases, maintenance and repair is planned to be done during port visits, but in the event the radar needs repair while still at sea almost 95 percent of the array’s maintenance comes down to just a few unique parts,” Spence explains.

Technicians can switch them out within six minutes using only two tools. Simplicity, reliability, and design for manufacturing and assembly were top of mind for AMDR’s engineers. The radar requires 70 percent fewer unique parts (line-replaceable units or LRUs) than the existing system on today’s DDG 51 ship. Because of this, the time and effort needed to make repairs are minimalized,” Spence notes.

At this stage, the SPY-6(V) continues its testing and will be stressed by “increasing the range and complexity of targets, and demonstrating the radar is meeting its performance,” says Navy Captain Seiko Okano, major program manager for Above Water Sensors, Program Executive Office Integrated Warfare Systems. “AN/SPY-6 is the nation’s most advanced radar and will be the cornerstone of the U.S. Navy’s surface combatants for many decades.”

Old ship-to-ship communications approach gets a “retro”-style update

A new ship-to-ship communication system called “Flashing light to text converter” (FLTC), which is sponsored by the U.S. Office of Naval Research’s TechSolutions program, features a camera that can be mounted atop a signal lamp to hone in on Morse code bursts from another ship’s lamp within view. Handheld devices or laptop computers connected to the camera display text messages sent and received.

The process for sending messages using signal lamps hasn’t really changed much since World War II, so this new system marks a significant improvement because sailors no longer need to know Morse code to send or receive messages.

Previously, someone trained in Morse code needed to operate the lamp’s shutter by hand, which involves receiving, decoding, and replying to messages. Now, sailors can use FLTC to respond quickly and easily with fewer mistakes, according to the Office of Naval Research.

When the system was recently put to the test aboard the guided-missile destroyer USS Stout, the signal lamp flashed fast light bursts to the guided-missile cruiser USS Monterey, which was located 250 feet away. Aboard the USS Monterey, its signal lamp used a GoPro camera to receive the incoming Morse code and then converted it into text on a handheld device. The first message sent was “random.” Scott Lowery, an engineer at the Naval Surface Warfare Center in Panama City, Florida, had asked the USS Stout to send a random message and was amused when they complied more literally than he expected. “Simple, but it shows the system is working,” he says.

How exactly does the system work? By linking a commercially available camera and device with a proprietary converter that uses software algorithms to process the incoming light flashes into high-frequency signals, it converts those signals into text messages. To reply to a text, sailors can use the device to simply type a response that gets sent back in Morse code, thanks to specially powered LED lights that flash automatically.

What do sailors think of using the FLTC system? The best part of the converter, according to Lowery, is its ease of use. “It’s very intuitive because it mirrors the messaging systems used on iPhones,” he says. “You just type your message and send it with the push of a button.”

During certain communication-denied scenarios at sea when satellite communications is either risky or unavailable, ONR Command Master Chief Matt Matteson notes that FLTC would be useful. It could be “extremely valuable if a ship’s main communications go down or if it needs to maintain a low electronic signature to avoid detection by an adversary,” he adds.

In the near future, standard retrofit kits might be placed on all existing signal lamps. Lowery and his team hope to see the system issued throughout the fleet as early as next year.