Why GPS Is Getting Worse — And May Force Us To Revert To Old-School Maps

Updated Feb. 9, 2025 at 3:42 p.m.*

HAMBURG — In Cyprus, people can run on water and swim through airports — at least according to their electronic devices.

A jogger from the city of Larnaka reported on the social network Reddit that his Garmin watch suddenly located him in Lebanon after his run. According to his smartwatch, a swimmer who was bathing in the sea off Cyprus swam across the Beirut airport. Cypriot delivery services and taxis are temporarily unable to reach their destinations. Dating apps suddenly seem to suggest Cypriots should start long-distance relationships.

This is sometimes funny, often annoying and rarely dangerous. The culprits for this mess are jammers in Israel or Syria that manipulate the Global Positioning System (GPS) for strategic reasons. Yet when you are a pilot responsible for an aircraft, things can get a little scary.

Experts distinguish between jamming and spoofing. Jamming involves transmitting signals on the GPS frequency that are so strong that the receivers in aircraft and on the ground stop working.

“We’ve seen this for years when approaching Seoul,” says Niklas Ahrens from the European Cockpit Association, a trade union that represents pilots. The airport is just 35 kilometers from North Korea. “You can be relatively sure that you won’t have GPS available when approaching.”

Ahrens regularly flies an Airbus 330 or 340 around the world as a co-pilot for a major airline. If the GPS fails, he lands with the help of radio beacons on the ground and the air traffic controllers, who locate the aircraft using radar and maintain radio contact.

Tricks of “Spoofing”

GPS spoofing is more sophisticated. Here, jammers trick the receiver into thinking it has a false position. In the airspace over Syria, Lebanon, Israel and Cyprus, the aircraft’s position sometimes jumps abruptly to Beirut, and the speed shown in the cockpit drops to zero.

“This kind of manipulation is fairly easy to recognize,” Ahrens says. On the borders with Belarus and Russia, however, the spoofing attack often simulates a false, moving position. The computers do not immediately recognize this as a deception. “That’s more difficult, because we have to constantly question whether the position shown is still plausible,” Ahrens says.

Warring parties disrupt GPS signals to confuse enemy drones and aircraft. In 2020, U.S. researchers located a jammer on the Syrian coast at an airfield operated by Russia. With the wars in Ukraine and Gaza, interference has increased. This affects numerous flights from Europe to Asia.

Disrupting flights

Because Russian airspace is closed to them, they have to detour over the southern Black Sea, where they are within range of the jammers. The disorientation of the local population and civil air traffic — even in their own country — is accepted as collateral damage. In Moscow, you can no longer rely on navigation apps. Rental bikes and scooters regularly stop working.

We now see around 1,000 aircrafts a day affected by spoofing worldwide.

The true extent of GPS manipulation is revealed by data from the OpenSky network, a grassroots movement whose members use homemade receivers to analyze the position of aircrafts. At the beginning of November, the movement met at the Center for Applied Aviation Research in Hamburg for a world conference. Michael Felux traveled from the University of Applied Sciences in Zurich. He and his team evaluated the data from 1 million flights in three zones: over Poland and the Baltic States; over Romania, Bulgaria and Moldova; and over Cyprus and the eastern Mediterranean.

On almost 70,000 flights between February and August 2022, GPS navigation was disrupted or failed due to jamming. Over the eastern Mediterranean, more than every second flight was affected.

“You can imagine jamming as having the person you want to listen to trying to whisper in your ear, all while your baby is screaming at the top of his lungs,” says Felux, who recently became a father himself. In this comparison, the baby is the jammer, and the whispering is the weak satellite signals.

Jamming is easy and cheap. Some taxi and truck drivers use transmitters with USB connections to prevent their vehicles from being tracked. Ship captains manipulate their position transmitters to conceal fishing in illegal fishing zones. Electronics costing a few hundred euros are enough to jam airplanes.

Stressed in the cockpit

But now, the troublemakers are increasingly turning to more sophisticated acts of spoofing.

“We now see around 1,000 aircrafts a day affected by this worldwide,” says Felux’s colleague Raphael Monstein, who visualizes the data at spoofing.skai-data-services.com. “If you fly out of Tel Aviv, you’re practically certain you will face spoofing.” Pilot Ahrens confirms this.

Airplanes do not crash if satellite navigation is disrupted. They rely on conventional navigation techniques. First, inertial navigation: Sensors in the aircraft measure every movement and acceleration and use this to calculate the position. Second, radio navigation: The aircraft tracks several ground stations and measures the distance to them. Third, radar: Air traffic control locates the aircraft and radios control instructions to the cockpit.

But the stress level in the cockpit and at air traffic control is increasing, and not just in the vicinity of wars.

The problem is that a GPS receiver cannot simply be restarted after a disruption. It stops working until the aircraft lands, even if the aircraft has left the interference zone. And since traditional navigation is less accurate than high-precision GPS technology, the position uncertainty over the sea can be more than ten kilometers. That’s why aircraft have to maintain greater safety distances: Spoofing means fewer aircrafts can fit in the air at the same time.

Sounding the alarm

Perhaps the biggest problem: Spoofing can manipulate the displayed altitude and thereby trigger an alarm. If an aircraft is descending and the on-board electronics are tricked into thinking that the plane is flying much lower and on a collision course with a mountain, then the pull-up alarm sounds.

In this case, the crew should pull the aircraft up as steeply as possible. If it’s a false alarm, the pilot ignores the warning. But pull-up is the queen of alarms. It suppresses all other warnings, including those about an impending collision with other aircrafts — very inconvenient. So many airlines now resort to automatically switching off the pull-up alarm near crisis areas.

In August 2024, pilots and air traffic controllers met in Frankfurt to discuss the situation. The impact of GPS spoofing on cockpit instruments is currently one of the most important security issues, they wrote. Yet “there is currently little that can be done to prevent this.”

But because aviation is slow to introduce any innovations.

Ahrens was there for European Cockpit Association. He has called on countries to stop dismantling the outdated-looking ground antennas, as they have been doing so far. By 2030 at the latest, all commercial aircraft in the EU should actually be able to land using satellites. Conventional navigation would only be permitted in emergencies.

And yet, pilots think that that’s simply not a good idea. “We need redundancy,” Ahrens says, “the systems must become more resilient.”

There are ideas to make satellite navigation more resilient. For one, the European GPS alternative Galileo has been testing an encryption technology in recent months that is supposed to be immune to spoofing. Another option would be to install new antennas in aircraft that are programmed to only receive signals from above, where the satellites are orbiting. But because aviation is slow to introduce any innovations, it will take years until the technology is certified.

Ahrens learned how to fly a plane a long time ago, in the age of paper maps. On a long-haul flight, he had to turn the pages quite often. That doesn’t happen anymore. Pilots use digital maps on an iPad. Hopefully they won’t crash.

*Originally published Feb. 5, 2025, this article was updated Feb. 9, 2025 with enriched media.