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.

GPS Glitch Grounds GoPro Drones

GoPro KarmaGoPro’s Karma drone, released in October 2016 and discontinued in January 2018 (when GoPro announced it was getting out of the drone business), has apparently fallen prey to the GPS rollover bug: they’ve been grounded since the new year. See coverage at DP Review, Engadget and The Verge, as well as  discussions at GoPro’s support website.

GoPro says they’re “actively troubleshooting” the issue; I have to say I’m surprised that a relatively new gadget—between two to three years old—could be hit by a once-every-19.7-year bug.

Previously: Happy GPS Week Rollover!

Beidou, China’s Satellite Navigation System, to Be Complete by June

Beidou logoChina’s Beidou satellite navigation system—a competitor to GPS like Russia’s GLONASS and Europe’s Galileo—will be complete by June 2020, when the constellation’s final two satellites are launched, the Associated Press reports. Twenty-four satellites have already been orbited. Whereas the first two iterations of Beidou offered regional coverage, this third iteration will cover the globe when complete. [Engadget, TechCrunch]

GPS Is Easy to Disrupt, and the Consequences of Disruption Are Serious

In an article in the December 2019 issue of Scientific American, now available online, Paul Tullis looks at the problem of GPS hacking, or spoofing—how easy it is to do, how vulnerable GPS is to it, and the consequences we’d face if GPS was disrupted on a broad level. It’s essential but scary reading. The potential scenarios Tullis describes are far more serious than the instances of GPS spoofing we’ve seen so far. It’s not just about navigation: a lot of critical infrastructure relies on GPS timestamps.

Tullis points out that other GNSS systems have terrestrial-based backup systems; GPS does not, despite a 15-year-old directive to build an eLORAN backup that would put out a signal too strong to spoof.

Previously: A GPS Spoofing Mystery in Shanghai; The Russians Are Spoofing! The Russians Are Spoofing!

A GPS Spoofing Mystery in Shanghai

Someone is spoofing GPS signals in Shanghai, and we’re not entirely sure why they’re doing it, or how. One ostensibly bizarre theory: sand thieves trying to obfuscate illegal dredging by zonking out the GPS received by other ships’ AIS transponders. But how they’re redesignating ship (and bicycle) GPS locations into riverside circles, rather than, say, shifting everyone’s position a few kilometres away, has not yet been figured out. [MetaFilter]

Previously: The Russians Are Spoofing! The Russians Are Spoofing!

GPS Units: Still a Thing

Wirecutter’s Medea Giordano argues that even in the age of smartphones with built-in map apps, there’s still a place in your car for a dedicated GPS device: “there are cases when a phone just doesn’t cut it—say, in rural areas where coverage is questionable, or if you simply don’t want to drain your phone’s battery and data plan. Or when you’ve just found it frustrating to use a phone for long trips, like I have.”

Many Moon Maps

National Geographic’s 1969 map of the Moon

With the 50th anniversary of Apollo 11 almost upon us, there’s been an uptick in moon-related content, which includes moon-related map content. For example:

New Exhibition. Opening today at The Map House in London, The Mapping of the Moon: 1669-1969, an exhibition of three centuries of lunar cartography. “The exhibition includes rare early 17th and 18th Century observations of the moon from astronomers such as Athanasius Kircher and Jean-Dominique Cassini, important maps produced by NASA for lunar exploration, globes and signed material by astronauts Neil Armstrong, Buzz Aldrin, Alan Bean and Jim Lovell.” Runs until 21 July. [ARTFIXDaily]

New Map. The July 2019 issue of National Geographic has a new map of the Moon that updates the 1969 painted version (see above) with a mosaic based on Lunar Reconnaissance Orbiter imagery. I don’t know whether that means a physical version of the map will be included with the issue as an insert, but I hope it does.

New Way to Navigate. NASA has a post on using GPS on the Moon. Now, I’d thought that using GPS on another world would require the deployment of a GPS satellite constellation around said world. No, this is about using Earth-orbiting GPS signals for lunar navigation, which simulations suggest is possible. The mind boggles.

The Economic Impact of GPS—and GPS Outages

A new study quantifies the economic benefits of GPS: in the U.S. alone, it estimates around $1.4 trillion in economic activity resulting from private-sector GPS use, about half of that coming from improvements in the telecommunications sector. (Roughly a quarter came from the telematics sector, and 15 percent from location-based services.) About 90 percent of those benefits have been generated in the last decade. The study also quantified the impact of a GPS outage: about a billion dollars a day, more if it occurred during planting season (agriculture has become reliant on GPS). [Ars Technica]

FAA

And speaking of GPS outages, earlier this month hundreds of flights were grounded over what appeared at first to be a GPS signal problem, but turned out to be a technical issue with GPS receivers made by Collins Aerospace. About 400 flights were cancelled on Sunday, 9 June, mostly involving Bombardier regional jets, but also other airliners and private aircraft. The FAA instructed pilots of affected aircraft to use other navigation methods; Collins says it has identified the issue and is working with the airlines. Coverage: AINonline, FlightGlobal, Forbes, GPS World, RNTF. [Jason Rabinowitz]

Wayfinding: A New Book about the Neuroscience of Navigation

M. R. O’Connor’s book Wayfinding: The Science and Mystery of How Humans Navigate the World came out in April from St. Martin’s Press. Not coincidentally, she’s published a couple of pieces on the subject of that book, both of which focus on humans’ ability to pay attention to their surroundings, and the effect that relying on GPS directions might have on that ability. In a piece for Undark, O’Connor argues that “our unshakeable trust in GPS,” which traces itself back through hundreds of years of believing in the infallibility of maps, gets us lost because we’re relying on the device rather than our senses. Her piece for the Washington Post focuses on the role of the hippocampus in navigation and spatial awareness, and the need to exercise that part of the brain.

This is not the first book on the subject: Greg Milner published Pinpoint in 2016 (previously). See also: Satnavs and ‘Switching Off’ the Brain.

Garmin Announces the Overlander, An Offroading GPS Receiver

Garmin Overlander (Garmin)
Garmin

Garmin announced the Overlander GPS receiver today. It’s designed for off-road, off-grid navigation, with maps that include public lands boundaries and 4×4 trails (in the Americas, at least), sensors to detect roll and pitch angles, and other features suitable for mucking around in a Jeep or ATV. Costs $700. [Engadget]

Anyone who assumes that the GPS device market has been killed by smartphones will be (a) surprised that Garmin is still around and (b) wrong. Though its automotive segment continues to decline—last quarter it was down to only 16.6 percent of Garmin’s revenues, making it Garmin’s smallest market segment—Garmin continues to do well in other market segments. Building devices for very specialized uses, for which a smartphone app might not be up for the task—see above—seems to be one of the ways it goes about that.

The Russians Are Spoofing! The Russians Are Spoofing!

Russian authorities appear to be systematically messing with GPS and other GNSS signals in multiple locations, a new report from the Center for Advanced Defense Studies concludes (CBS News, Foreign Policy, Moscow Times, Wired). The tactic is called GPS spoofing: broadcasting a false GPS/GNSS signal in a specific location to fool GPS/GNSS receivers and render them unreliable or unusable. The incidents appear to correlate with sensitive Russian facilities, active combat zones, and the travel itinerary of one Vladimir V. Putin. In one case, while Putin was opening a bridge between Russia and Crimea, nearby ships were suddenly informed by their GPS/GNSS receivers that they were dozens of kilometres away from their actual position.

Happy GPS Week Rollover!

It’s probably overstating things to compare the GPS week rollover to the Y2K bug (The Next Web, The Verge) but it’s hard not to see some parallels. In each case, it’s a function of too little memory assigned to timestamps.

One of the things that GPS satellites do is transmit precise timing information. It does this in part by stating the week as a 10-bit integer, counting from week one. That means the date number rolls over every 1,024 weeks. Every 19.7 years, then, the GPS week “rolls over” and a new GPS epoch begins. It’s already happened once: the GPS era started on 6 January 1980, and the first rollover occured in August 1999. The next one takes place—oh dear—tomorrow. Cue the mass hysteria.

How will our GPS receivers respond to that rollover? Because it’s happened before, and because consumer GPS tech doesn’t necessarily stay in use for long periods of time, it’s unlikely that your or my GPS receivers are affected. Anything released in the past two decades would have programmed after the last rollover. Also, receivers might have have had an offset to the 1,024-week limit programmed into their firmware, starting the clock from the date of compilation rather than August 1999, so devices affected may not be affected all at once. U.S. government agencies note that GPS receivers that conform to the IS-GPS-200 specification should not be affected: PC Mag pins that on devices manufactured in 2010 or later.

My own legacy GPS receivers—a Garmin eTrex Legend H and an Oregon 450t—date from just before 2010, and while I haven’t used them in years (when your smartphone has built-in GPS, dedicated receivers are superfluous in the most common use cases), I’m half tempted to fire them up and see what happens. Both TomTom and Garmin claim that the vast majority of their devices are unaffected, but neither go so far as to give us a list of affected devices. Firmware updates are apparently being issued for some of those affected devices—but again, a list would help.

In any event, it appears that using GPS for location, even on an affected device, will not be broken: at worst your tracklogs will have inaccurate timestamps. Receivers that use GPS for accurate timekeeping that have not been updated to handle the rollover might run into some trouble, though. And, like Y2K, any problems might be in industrial or embedded systems rather than consumer tech—and from what I’ve seen online they’ve been getting warnings about this for years.

In other words, as far as I can tell, the GPS world will not come crashing down tomorrow.

Galileo Approved in the United States

Galileo logoThe FCC has approved the use of the European Galileo satellite navigation system in mobile devices in the United States. Galileo is similar to GPS and the Russian GLONASS, but the satellite constellation won’t be complete until 2020 or so. Even so, devices like recent iPhones (from the 8 and X on) have support built-in. (Many smartphones have had GLONASS support for years.) FCC press release.

Pentagon Tells Personnel to Turn Off Geolocation in Sensitive Areas

In the wake of reports that fitness apps’ user data was exposed and could be used to identify military and intelligence personnel in sensitive areas like bases and deployment zones, U.S. military and defense employees can no longer use geolocation features in devices and apps in operational areas. The new policy was announced last Friday. Also see coverage at Stars and Stripes. [Gizmodo]

Previously: Strava Heat Map Reveals Soldiers’ LocationsNon-Anonymized Strava User Data Is AccessibleStrava, Responding to Security Concerns, Disables FeaturesPolar Flow User Data Can Be Used to Identify Military and Intelligence Personnel.