Startups map out strategies to augment or backup GPS
by Debra Werner — SpaceNews
Companies investing billions of dollars in autonomous cars, delivery drones and urban air taxis are counting on precise and reliable location data being available when they need it.
GPS-level accuracy of 4.9 meters for a smartphone operating under clear skies won’t be good enough. Before autonomous cars can speed down highways, they will need to know their location within around 10 centimeters with roughly one error every billion miles.
“When you start doing the math, you realize almost every car in your fleet has to have sub-10-centimeter accuracy for its entire lifetime,” said Patrick Shannon, CEO and co-founder of TrustPoint, a startup based in Silicon Valley and Northern Virginia developing a new global navigation satellite system (GNSS).
TrustPoint, founded in 2020, is not alone in seeing skyhigh potential for a 21st century GNSS augmentation system or alternative. Xona Space Systems, founded in San Mateo, California, in 2019, is working toward the same goal.
“GPS was designed to support human operators,” said Brian Manning, Xona CEO and co-founder. “In the modern world, humans are quickly becoming passengers, or they’re being taken out of the loop altogether. The machines replacing them have very different requirements when it comes down to accuracy, security and resilience.”
GPS ALTERNATIVES
Startups and established companies developing commercial positioning, navigation and timing constellations or alternative technologies don’t intend to replace GPS.
“GPS is amazing, don’t get me wrong,” said Michael O’Connor, CEO of Reston, Virginia-based Satelles, which provides positioning, navigation and timing signals from the Iridium Next satellites. “It’s become a utility, which is part of the problem.”
GPS reliance is so pervasive, in fact, that disruption or manipulation of its signal could threaten U.S. national and economic security. That message was conveyed by the White House in a 2020 Executive Order and a 2021 Space Policy Directive.
The U.S. Transportation Department delivered a report to Congress in January after testing alternative location and timing technologies. And the Department of Homeland Security is working with the Cybersecurity and Infrastructure Security Agency to ensure the electric grid, emergency services and other components of the nation’s critical infrastructure are not solely reliant on GPS.
“People realize GPS is a single point of failure for the entire U.S. economy,” Manning said. “Nothing else out there that can match it.”
U.S. government efforts to identify technologies to complement or backup GPS are helping fund alternatives.
Xona won a Small Business Innovation Research grant in 2020 from the National Science Foundation for research related to its proposed low Earth orbit constellation.
Satelles is an Iridium Communications’ subcontractor on a U.S. Army contract to develop a hosted payload for a small satellite constellation with applications for navigation, guidance and control.
Since 2016, Satelles has offered timing and location signals through a channel on Iridium Next satellites that was reserved for paging in the original Iridium constellation.
“Since not many people wear pagers on their belts anymore, we use Iridium’s L-band frequencies for our positioning, navigation and timing signals,” O’Connor said.
Satelles broadcasts an encoded signal that offers accuracy of 20 meters or better for stationary devices around the world and precise timing within three nanoseconds.
“We offer this service to critical infrastructure sectors, data centers, wireless infrastructure providers, energy companies and so forth,” O’Connor said.
AGE OF AUTONOMY
TrustPoint and Xona are more focused on emerging markets.
TrustPoint intends to support 21st century technologies like self-driving cars, air taxis, drone delivery services and augmented reality applications being developed by commercial and government customers.
The global market for GNSS receivers, ranging from inexpensive chipsets to precision devices that cost over $10,000, is projected to grow from a current level of roughly $55 billion a year to over $175 billion by 2029, according to a 2019 report by the European Global Navigation Satellite Systems Agency.
Before co-founding TrustPoint, Shannon, a former vice president at Astro Digital and SpaceQuest, considered various business opportunities. When he began looking into “innovating on GPS and revitalizing that industry,” he realized “the user base was just ginormous.”
Xona was founded with an eye toward the autonomous vehicles market. Manning’s co-founder Tyler Reid helped write standards for autonomous cars while working as a research engineer in Ford Motor Co.’s controls and automated systems organization.
Reid, now Xona’s chief technology officer, wrote “standards on autonomous car accuracy, integrity and resilience targets,” Manning said. “We found that if you can meet the needs of autonomous cars, you can pretty much meet the needs of everything.”
INDEPENDENT CONSTELLATIONS
Both TrustPoint and Xona intend to establish small satellite constellations in low Earth orbit to offer global positioning, navigation and timing services independent of existing GNSS constellations. Initially, though, the new constellations intend to make money by augmenting GNSS data to offer higher precision.
“Leveraging the tens of billions of dollars of GNSS infrastructure from around the globe that already exists means you don’t have to replicate it for your own system,” Manning said. “Now, if something goes completely haywire, and all the GNSS constellations go down or go dark, our system can continue to operate fully independently, just at a reduced level of accuracy from the centimeter level performance.”
Xona intends to fly its payload on cubesats and offer its service through subscription fees. In a national emergency, however, the company could activate its service on all devices to serve as a GNSS backup, Manning said.
TrustPoint plans to establish a constellation of microsatellites in a series of steps.
“Filling out a constellation that can operate on its own and manage its own timing to get accurate positioning on the ground will take time and will require hundreds of satellites,” said Chris DeMay, TrustPoint co-founder and chief operating officer. “In the meantime, TrustPoint has a solid plan for deploying an interim constellation that still adds a ton of value by augmenting GPS.”
The cost of commercial TrustPoint service is likely to be built into devices, rather than requiring a subscription. Government customers seeking specific security features may opt for subscriptions.
JAMMING AND SPOOFING
A key advantage of delivering location and timing signals from low Earth orbit is power.
GNSS signals traveling 20,200 kilometers from medium Earth orbit to receivers on the ground can be disrupted by low-power devices.
The problem was demonstrated vividly in 2013 when a truck driver, who spent less than $100 on a GPS jammer he plugged into a cigarette lighter, inadvertently disrupted air traffic control at Newark Liberty International Airport.
“Iridium satellites are 25 times closer to the earth than GPS satellites and their beams are much more focused,” O’Connor said. “The net impact is that the signal received on the ground is about 1,000 times stronger than GPS.”
With that extra power, Satelles proved in Transportation Department tests in 2020 that its signal extends indoors and even into basements. The extra power also makes it “much more resilient to any kind of intentional or unintentional interference,” O’Connor said.
Spoofing is another concern for GNSS customers.
Pokémon Go, an augmented reality application for smartphones released in 2016, encouraged players to catch and train virtual Pokémon characters. Players quickly learned, though, that instead of traveling to various sites to find the characters, they could manipulate GPS signals to make it appear they were somewhere else.
“It’s a lot easier to sit on my couch and build a spoofer than it is to actually go get a Pokémon,” Manning said.
While spoofing in Pokémon Go isn’t a serious problem, spoofing an autonomous car’s location would be.
Satelles has encoded its signal to make spoofing “virtually impossible,” O’Connor said.
TrustPoint’s DeMay said, “In a world increasingly plagued by cyberattacks and electronic warfare, we not only want to provide a more accurate service, but also, as alluded to in our company name, a service that can be trusted to support safety-critical applications.
To maintain security, Xona plans to continuously update hardware and software.
“We are designing our security such that it can be upgraded at the speed of the technology,” Manning said.
While there is competition among the positioning, navigation and timing startups for contracts and investment, the enormous global market potential and national security concerns make it unlikely that one company or technology will eclipse all others.
“I think there will be multiple systems to build as much resilience into the PNT ecosystem as possible,” Shannon said. “If GPS goes down, you’ve got a LEO system. If we’ve got a crazy space weather event, there are terrestrial positioning systems available. There will be a lot of players.”
This article originally appeared in the July 2021 issue of SpaceNews magazine.
AUGUST 4, 2021