November 20, 2023
In modern warfare, where signal jamming is now as common as bullets and bombs, the ability to navigate without GPS guide stars has become a critical survival skill for today’s soldier.
The modern battlefield has become a complex chessboard where traditional lines of navigation and communication are constantly blurred and altered.
As adversaries become more adept at jamming GPS signals, the U.S. military is turning to advanced navigation equipment for soldiers. Technologies such as wireless communications between soldiers, body area networks, and battlefield energy storage and generation are at the forefront of this effort.
These innovations not only keep soldiers connected; rather, it is about redefining the very fabric of military strategy and operations in environments where traditional navigation and timing tools become obsolete.
Diverse environments – from the dense forest canopy to the steel canyons of urban sprawl – demand precision, adaptability and the relentless pursuit of innovation within the strict constraints of increasingly size, weight and power (SWaP) demands. little ones.
The answers lie not only in hardware but also in emerging technologies such as artificial intelligence (AI) and machine learning (ML), where rapid processing of sensor data and fusion of sensors in mesh networks can help create corrections. precise positionals.
“If soldiers share a common mesh network and a single soldier in the network has generated a trusted position, the positions of all other soldiers in the network are known instantly,” says Chris Hohne, principal engineer at Benchmark Secure Technology (Santa Ana). , California). “If a soldier is at the edge of a network and is only visible to one or two nodes, the position information will be degraded and the map will show a large area of uncertainty. However, if more than two nodes are seen, the position accuracy will exceed that of GPS.”
Strategic and technical obstacles
While companies are moving forward with solutions like these, there are some broader strategic concerns. Dana Goward, president of the Resilient Navigation and Timing Foundation – an organization that aims to protect critical infrastructure by promoting resilient navigation and timing around the world – says there are inherent risks in the Defense Department’s strategy of United States (DoD) when it comes to GPS.
“There is a lot of technology available that can make it more difficult to interfere with GPS receivers,” says Goward. “This is important because the Department of Defense has said that GPS will be the centerpiece of its PNT efforts in the future.”
The emergence of complementary and alternative systems may help, but the Department of Defense has not provided any direction on the path forward, Goward says, attributing this to a lack of leadership support for alternative systems, a situation that could leave The military is at a disadvantage if the GPS systems are compromised. (Figure 1.)
(Figure 1 ǀ There are some potential risks in making GPS the centerpiece of government NWP efforts, says the president of the Resilient Navigation and Timing Foundation.)
These alternative navigation options aim to address a wide range of technical challenges facing today’s soldiers. The need for precision and accuracy in position and timing data is driving much of the development, Hohne says, adding that the variability of environments (such as urban areas, forests or oceans) adds complexity.
“The biggest challenges in developing solutions for non-GPS environments are the wide range of products that must be supported, the variability of the environment in various theaters of operations, and SWaP (size, weight and power) considerations,” he continues. “Many of our systems have been designed to operate with an integrated GPS receiver that is smaller than a quarter and consumes a lot of power.”
The technical obstacles are not just about navigation, but also about ensuring that military systems can access data regardless of the state of the GPS signal, says Matt Sieber, director of programs and requirements for the Department of Defense at Kymeta (Redmond, Washington). The challenge: balancing the accuracy of A2-PNT solutions with affordability for the Department of Defense, he adds.
Distributed AI and machine learning have been a game-changer, enabling rapid processing of sensor data and facilitating sensor fusion for precise positional corrections, Hohne notes. These technologies can adapt to different environments, thereby improving navigation accuracy by weighing sensor inputs based on their reliability.
“AI/ML can also facilitate sensor fusion, where data from multiple sensors is combined to create a more accurate and reliable navigation solution,” he adds.
Open standards, such as the Sensor Open Systems Architecture (SOSA) Technical Standard, will be key to helping the military develop systems that can address the challenge of non-GPS environments in the future. SOSA allows for rapid iteration and evolution of systems, Hohne says, noting that in the context of non-GPS operations, no single product will be sufficient; Instead, you need a product system that can adapt and evolve quickly as threats change.
“Open standards like SOSA are critical to this effort because they provide a mechanism for a ‘system’ to rapidly iterate and evolve,” he continues. “SOSA and other open standards break vendor lock-in and provide a method for the combined intellect of our nation and our allies to develop solutions, include them in existing weapons systems, and verify that they solve the problem at hand. SOSA systems then allow existing weapons systems to be updated in hours instead of days or weeks.”
Energy consumption management
As exciting technologies continue to emerge, energy consumption remains one of the most difficult elements to address. Hohne says his company’s MicroRadio design is designed to minimize power consumption through design operations, embedded software optimization, and RF power output management.
“MicroRadio was specifically designed to reduce power consumption and extend operation with a small internal battery,” he says. “Design crafts, iteration and evolution allowed us to reduce the design to a small group of low-power components, optimize the software/firmware and embedded algorithms, manage RF power output, and minimize and add processes in second flat”.
For its part, Kymeta’s Osprey u8 HGL system uses holographic beamforming techniques, which require significantly less power than traditional phased array solutions, and often run on the vehicle’s native DC power without additional equipment, Sieber says. (Figure 2.)
(Figure 2 | The Osprey u8 HGL mobile terminal is designed to operate independently of GPS signal availability).
“Osprey u8 HGL differentiates itself from many of the traditional phased array solutions that will hit the market in the near term by employing holographic beamforming techniques using a passive metasurface antenna,” he says. “One of the main benefits of this technology is that it uses between half and a tenth of the energy consumption required by competing products.”
The future of sensor navigation
Improving sensor navigation is an ongoing effort and the industry must design systems that can integrate new sensors and systems as they become available. By designing them to be plug and play, soldiers can take advantage of new technologies such as video sensors, accelerometers, gyroscopes, and magnetometers almost immediately.
“New sensors and systems can be integrated into the soldier by simply placing them on the vest, placing them in a pocket, or wearing them as an article of clothing,” Hohne says.
Hohne says he envisions a future where distributed AI/ML will be the cornerstone and sees the evolution of data collection, storage and distribution as critical to developing robust, tactically cutting-edge military models.
The growing number of low Earth orbit (LEO) and medium Earth orbit (MEO) satellites is a huge benefit to the sensor navigation industry, says Sieber. He predicts that the ability to use non-cooperative or non-standard signals from these satellites for precise location and navigation services, combined with an alternative solution for precise timekeeping, will significantly reduce the Department of Defense’s reliance on GPS.
“The number of satellites in low and medium Earth orbit in space is increasing at a rate unimaginable just a few years ago,” says Hohne. “There are several companies striving to use non-cooperative signals of interest from GEO, LEO and MEO satellites for precise location determination and navigation services.”
Goward agrees that these satellites could be critical in the future: “If there is a leader among all systems, it is probably the PNT of low Earth orbit satellites: better than GPS, stronger signal and potentially even more accurate “, it states.
However, he cautions that while LEO satellites offer signal diversity and coding advantages, they share common failure modes with traditional GPS due to their very nature as satellites. This reality means that designers must consider the difficulty of getting ahead of the explosion and preventing disruptions: “Basically, people find it difficult to get ahead of the explosion and prevent bad things from happening.”