Saturday Morning Breakfast Cereal has a take on what GPS does to our ability to navigate.
SuperGPS Promises Ten-Centimetre Accuracy
It seems to be steam engine time for GPS alternatives. We’ve already seen two proposals that suggest using constellations of low-flying satellites to provide greater accuracy and more resilience against signal blocking than GPS and other orbital navigation systems can provide. Now a research team in the Netherlands is developing a project called SuperGPS, which promises decimetre-level (10 cm) accuracy through the use of terrestrial transmitters connected to a fibre-optic network. They’ve built a working prototype, and published the results in Nature. More at the TU Delft news release.
Previously: Starlink as GPS Alternative; ESA Considering Low-Orbit Satellites to Improve Galileo System.
ESA Considering Low-Orbit Satellites to Improve Galileo System
The idea of using low-earth-orbit satellites to provide greater GPS/GNSS accuracy isn’t limited to commandeering the Starlink constellation. The European Space Agency is exploring the idea of using low-flying satellites to increase Galileo’s accuracy and robustness: make it possible to use indoors, make it more resistant to jamming and interference, and enable positioning at the centimetre level. They’re planning an in-orbit demonstration of around six satellites to test the proposition. The satellites would supplement the existing Galileo constellation rather than replace it: for one thing, they would rely on the Galileo satellites’ atomic clocks, which would allow the low-flying satellites to be an order of magnitude smaller in size. [Universe Today]
Starlink as GPS Alternative
The point of SpaceX’s Starlink constellation, consisting of some 3,000 low-orbiting satellites (so far), is to provide broadband internet access. But it could also be used as an alternative to GPS that might be less susceptible to jamming or spoofing. The U.S. Army and a team at the University of Texas at Austin were interested in the idea, but SpaceX told them to go pound sand in 2020. Now said UT team has gone and reverse-engineered the Starlink signal to pinpoint a location to within 30 metres. Not as good as GPS, obviously, but the researchers say that a software update—and SpaceX’s cooperation—could get that accuracy down to within a metre. Their (non-peer-reviewed) paper is here. Coverage: El Reg, TechCrunch.
New Apple Watch Features Include Dual-Frequency GPS, Virtual Breadcrumbs
Apple is touting the Apple Watch Ultra’s dual-frequency GPS support, viz., it uses the GPS L5 band in addition to L1 to improve accuracy. The new L5 signal is higher power and is supposed to provide more robust service, but with only 17 satellites broadcasting on it it’s not yet fully operational. Still, a Reddit user was able to document the improved accuracy by conducting an unexpected stress test: mowing the lawn. With the Ultra the mowing rows can be made out, whereas the tracks made with a series 4 watch were all over the place. [9to5Mac]
While the Ultra is the only Apple Watch that can use the L5 band, watchOS 9 adds a redesigned Compass app and a Backtrack feature that lets users retrace their steps using on-the-fly waypoints and GPS traces. MacRumors has a tutorial. This is something I’m looking forward to trying out: my series 8 watch arrived last week.
India Pushing Phone Makers to Adopt NavIC
Reuters reports that the Indian government is pushing mobile phone makers to include support for NavIC, the Indian-government owned satellite navigation system. (At the moment NavIC provides regional coverage from a seven-satellite constellation, but the plan is for 24-satellite global coverage.) Phone makers are resisting the request, citing the additional chips and cost required to support the system. And there’s the matter of redundancy: the current iPhone, for example, already supports BeiDou, Galileo, GLONASS and QZSS in addition to GPS. [9to5Mac]
Ships Are Increasingly Spoofing Their Location
Ships spoofing their location is an increasing problem, Anatoly Kurmanaev reports for the New York Times. All large ships are required to carry an AIS transponder that transmits the ship’s ID and position, but some ships are starting to find a way around that.
[O]ver the past year, Windward, a large maritime data company that provides research to the United Nations, has uncovered more than 500 cases of ships manipulating their satellite navigation systems to hide their locations. The vessels carry out the deception by adopting a technology that until recently was confined to the world’s most advanced navies. The technology, in essence, replicates the effect of a VPN cellphone app, making a ship appear to be in one place, while physically being elsewhere.
Its use has included Chinese fishing fleets hiding operations in protected waters off South America, tankers concealing stops in Iranian oil ports, and container ships obfuscating journeys in the Middle East. A U.S. intelligence official, who discussed confidential government assessments on the condition of anonymity, said the deception tactic had already been used for weapons and drug smuggling.
We’ve seen examples of this before, but this is starting to look like an endemic problem.
GPS Negatively Impacts Spatial Memory
Rebecca Solnit points to a 2020 study that attempts to measure the impact of using GPS navigation devices on our spatial memory. After assessing 50 drivers, researchers found that drivers with more GPS experience had worse spatial memory when navigating without GPS. But more significantly, it’s a longitudinal study: 13 of the participants (admittedly a small sample) were retested three years later, and greater GPS use correlated with a steeper decline in spatial memory.
This is a single study, and a small sample, so I’m hesitant to draw firm conclusions. And in any case it’s not necessarily a surprising conclusion: the more you rely on a tool, the less able you are to do without it. Well, yes. When we talk about how GPS is destroying our ability to navigate or read a map, there is a presumption that this is an objectively bad thing. Except that I’ve encountered too many people who couldn’t navigate their way out of a bag before GPS. A lot of people who let their GPS receivers get them lost were, I think, pretty good at getting themselves lost without it.
The question isn’t whether GPS use atrophies an individual’s ability to navigate: that’s like worrying that a calculator reduces your ability to do sums in your head, or that a word processor excuses you from knowing how to spell. Of course it does. Those of us who are good at navigation (or sums, or spelling) and think an important skill is being lost will clutch our pearls, but making something easier also makes it more accessible. The question is whether people are, on balance, at a societal level, getting lost less often. That’s not a question neuroscience can solve, nor something you can test with an fMRI. I’m not sure how to measure it, or even if it can be measured. But I’d love to find out.
Previously: Wayfinding: A New Book about the Neuroscience of Navigation; Satnavs and ‘Switching Off’ the Brain; McKinlay: ‘Use or Lose Our Navigation Skills’; ‘Could Society’s Embrace of GPS Be Eroding Our Cognitive Maps?’; How GPS Eats Our Brains.
Bartosz Ciechanowski Explains GPS
Bartosz Ciechanowski writes long, detailed explanatory articles about physics, math and engineering that are full of interactive, animated diagrams. His article on GPS, posted last January, digs down into all its fundamentals, from the principles of trilateration to the orbital mechanics of GPS satellites to exactly what a GPS signal consists of. “It’s fascinating how much complexity and ingenuity is hidden behind the simple act of observing one’s location in a mapping app on a smartphone. What I find particularly remarkable is how many different technological advancements were needed for GPS to work.”
Spacecraft Will Test Satnav Reception from Lunar Orbit
More on the astonishing idea that Earth-orbiting GNSS satellites can be used for navigation at the Moon. The European Space Agency reports that among the instruments carried by the upcoming Lunar Pathfinder commercial mission will be a 1.4 kg satnav receiver that will test its ability to receive GPS and Galileo signals from lunar orbit. “Satnav position fixes from the receiver will be compared with conventional radio ranging carried out using Lunar Pathfinder’s X-band transmitter as well as laser ranging performed using a retroreflector contributed by NASA and developed by the KBR company.” Lunar Pathfinder is currently scheduled to launch in 2024.
Previously: Many Moon Maps; Can GPS Be Used on the Moon?
America’s Overdependence on GPS
GPS signals are relied upon by critical parts of our infrastructure, from transportation to communications to agriculture to financial markets. But those signals are easily spoofed or jammed and, at least in the United States, have no real backup (despite legislation mandating one by last year). Kate Murphy’s opinion piece in the New York Times not only serves as a summary of the problem, and a warning, it also does so in the most mainstream of newspapers: most of what I’ve read on the subject has been in the business, tech and science media. More people will see this. [MAPS-L]
Previously: GPS Is Easy to Disrupt, and the Consequences of Disruption Are Serious; A GPS Spoofing Mystery in Shanghai; The Economic Impact of GPS—and GPS Outages; The Russians Are Spoofing! The Russians Are Spoofing!
Garmin’s Slow Recovery from Last Week’s Ransomware Attack
Engadget reports that Garmin’s services are starting to come back online after last week’s ransomware attack:
[I]t looks like things are slowly but surely coming back to life. Yesterday, activity-tracking app Strava confirmed that it was again able to send workout data to Garmin’s Connect service. […] But a quick look at Garmin’s system status page shows there are still plenty of issues across its platform.
Unfortunately, Garmin’s relative lack of communication around these issues means we still don’t know exactly what went wrong or when users can expect things to be back to normal. A few other key services, like registering a new device, are also back up and running, but if you’re still experiencing oddities with your Garmin devices, you’ll have to keep being patient.
Garmin’s FAQ on the outage is not particularly forthcoming.
Previously: Garmin’s Online Services Hit by Ransomware Attack.
Update, 1:48 PM: Garmin has issued a statement confirming that “it was the victim of a cyber attack that encrypted some of our systems on July 23, 2020.” There is no sign that customer data was affected, and they expect a return to normal within a few days. [Engadget]
Garmin’s Online Services Hit by Ransomware Attack
Garmin’s online services have been hit by a ransomware attack, TechCrunch reports, with outages still ongoing as of this writing. “The incident began late Wednesday and continued through the weekend, causing disruption to the company’s online services for millions of users, including Garmin Connect, which syncs user activity and data to the cloud and other devices. The attack also took down flyGarmin, its aviation navigation and route-planning service.” Email and call centres are also reportedly out of operation.
Four Articles on Navigating Outdoors
Outside’s Andrew Skurka has posted a four-part series on the skills and tools required to navigate outdoors (remember outdoors?), which in general means knowing how not to get lost. In part one, “A Backpacker’s Guide to Maps,” Skurka recommends what kind of maps to take with you: paper maps, mainly, of various scales, but with digital maps as a backup. Part two, “The Gear You Need to Navigate in the Backcountry,” looks at equipment: not just GPS, but also basics like a compass, altimeter and a watch. In part three, “How to Master Navigational Storytelling,” is about developing a narrative of the route you’re taking to avoid getting lost. Finally, Skurka offers a checklist of skills to test yourself against.
Previously: The Lost Art of Finding Our Way.
Can GPS Be Used on the Moon?
More on the question of whether GPS can be used for navigation on the lunar surface—that is to say the existing constellations of Earth-orbiting GNSS satellites, not a new constellation of satellites around the moon. A new study suggests that the answer is yes: GPS and other navigation systems could be used.
Cheung and Lee plotted the orbits of navigation satellites from the United States’s Global Positioning System and two of its counterparts, Europe’s Galileo and Russia’s GLONASS system—81 satellites in all. Most of them have directional antennas transmitting toward Earth’s surface, but their signals also radiate into space. Those signals, say the researchers, are strong enough to be read by spacecraft with fairly compact receivers near the moon. Cheung, Lee and their team calculated that a spacecraft in lunar orbit would be able to “see” between five and 13 satellites’ signals at any given time—enough to accurately determine its position in space to within 200 to 300 meters. In computer simulations, they were able to implement various methods for improving the accuracy substantially from there.
A mini-network of relays—a couple of satellites in lunar orbit, say—could improve accuracy further. [Geography Realm]
Previously: Many Moon Maps.
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