GPS, which is essential to a lot more than aircraft, ships and people on the road, is increasingly in the crosshairs. How do we function when its Positioning, Navigation and Timing services are not available?
By: Dave Dimlich
President of SD3IT
GPS is the lifeblood for a lot of modern activity. Taking a flight or boarding a cruise? GPS helps get you where you want to go. Buying or selling a stock? GPS helps ensure the integrity of the trade. Need to drive somewhere you’ve never been? When was the last time somebody on the road used a map or even had one in the car?
The signals and services provided by the Global Positioning System have become so deeply embedded in our lives that it’s best not to take them for granted. In fact, many people might not be aware of everything GPS does.
Military weapons’ guidance, aviation, maritime shipping and in-car navigation are likely the most recognized, but myriad other systems in a wide swath of sectors rely on GPS for everyday, but critical operations, courtesy of the Positioning, Navigation and Timing (PNT) data GPS supplies.
GPS satellites carry multiple, redundant atomic clocks that keep time with incredible precision, accurate to within a few nanoseconds. That precise timing enables mobile towers to synchronize data packets, which prevents calls from being dropped or disrupted. It makes it possible for stock exchanges and financial traders to accurately time-stamp billions of automated trades per second, which helps prevent fraud, and allows internet routing systems to log network traffic with GPS-provided time stamps. Precise GPS timing is also the basis for synchronizing the global power grid and time-stamping scientific data.
GPS also aids in weather forecasting, the routing of emergency services and the safe operation of autonomous vehicles. And not to be overlooked is how often it directs human drivers from Point A to Point B.
But despite its ubiquity and reliability, it is not guaranteed. The cozy blanket of GPS services can be snatched away—as a growing amount of evidence proves.
PNT Systems Under Fire
Electronic warfare, criminal activity and inexpensive radio equipment have made GPS interference increasingly common. Two primary threats have emerged:
- Jamming overwhelms legitimate satellite signals with radio noise, preventing receivers from determining their location or maintaining accurate timing.
- Spoofing is even more concerning. Rather than blocking GPS signals, attackers transmit counterfeit signals that convince receivers they are somewhere they are not. A system may continue operating without realizing the information it is receiving is false.
One cause of the problem is that GPS signals we receive are extremely weak, dropping to a tiny fraction of their original strength by the time they travel the roughly 12,550 miles from Medium Earth Orbit (MEO). That makes them surprisingly easy to disrupt with equipment that has steadily become less expensive and more accessible. You can buy a GPS jammer for about $20 (though using it is illegal), and more powerful jammers are readily available.
Incidents involving jamming or spoofing of GPS or other systems in the overarching Global Navigation Satellite System (GNSS)—which includes the U.S.-based GPS, Europe’s Galileo, Russia’s GLONASS and China’s nascent BeiDou—are becoming increasingly common and potentially dangerous.
Russia’s widespread electronic warfare activities in the Baltic region, including jamming and spoofing, has been blamed for the Baltic Bermuda Triangle, which as of June 2025 had disrupted more than 46,000 flights and caused a large number of ships to disappear from radar.
Commercial aviation has experienced multiple GPS disruption events that affected airport operations and flight routing. Maritime authorities report hundreds of ships affected every day, with groundings and collisions in 2024–25 publicly linked to interference of GPS and other satellite navigation systems, including in the Baltic Sea and the Strait of Hormuz. In December 2024, Azerbaijan Airlines Flight 8243 was struck by a Russian air-defense system, killing 38 passengers after the flight was diverted due to GPS interference. At sea, GPS interference in the Strait of Hormuz has caused oil tanker collisions.
Conflict zones from North Korea to Iran to the Black Sea and Baltic regions are the most common sites of GPS and GNSS disruptions, but incidents are spreading to non-conflict zones, including some in the United States, according to a warning from the Federal Aviation Administration.
And the threats from disruptions extend far beyond airline flights and ship navigation. When GPS becomes unreliable, the impact can ripple through operations much like a supply chain disruption. A single dependency can affect dozens of connected systems, something many organizations may not immediately recognize until something bad happens.
Operating Without GPS
Military organizations have long understood that GPS could become unavailable during conflicts. That’s one reason why the U.S. Naval Academy resumed teaching celestial navigation in 2015. It wasn’t for nostalgia’s sake; the Navy recognized that every technology needs a backup and, in this case, the backup technology included some of the tools used by Magellan in the 16th Century, although navigators have developed more sophisticated instruments since then, and the Navy’s course also includes a cybersecurity component.
But organizations across the board are adopting multiple approaches to strengthen PNT resilience.
Multi-frequency GNSS receivers can tap into signals from any satellites in the GNSS constellations, so if one system (such as GPS) is being disrupted—whether because of jamming, structural blockages or atmospheric interference—the receivers will automatically shift to another (say, Galileo). In addition to operational resilience, they provide greater accuracy than receivers that use only one positioning service. On the downside, multi-frequency GNSS receivers are more expensive and consume more power than basic receivers, and the implementation of their more complex hardware requires high levels of engineering and design expertise.
Some applications can combine GPS with inertial navigation systems, allowing operations to continue temporarily even after satellite signals are lost. Other systems use sensor fusion, visual navigation, terrain matching or other complementary technologies to create a layered approach that reduces the reliance on any single source of positioning information.
As a backup for GPS, several countries are turning to an enhanced version of Long Range Navigation (LORAN), a U.S.-developed radio navigation system that dates to World War II and, after several iterations, was retired in the 1990s. The enhanced eLORAN system uses solid-state transmitters operating at high-power on a low-frequency spectrum that is considered immune to jamming when used in conjunction with specialized digital receivers.
Equally important are operational procedures. Organizations should regularly test how critical systems perform when GPS is unavailable. Personnel should understand how to recognize spoofing or jamming events, how to transition to alternate capabilities and how to continue operations safely during degraded conditions. Well-prepared organizations combine resilient architecture with resilient processes.
Resilience Is the Key to Surviving GPS Outages
We’ve spent decades assuming GPS would always be available because, for the most part, it has always been like that. But that’s no longer guaranteed.
Organizations need to know that even critical, reliable technologies can be disrupted and ensure that they have resilient infrastructures and architectures so that operations can continue despite interruptions.
At SD3IT, our mission-focused approach to technology integration, implemented with a variety of expert partners, is designed to build resilience into the enterprise. Whether supporting federal agencies or commercial enterprises, we help organizations identify hidden dependencies, integrate resilient infrastructure and design architectures that continue supporting operations even when critical services are degraded.
As organizations become more dependent on interconnected technologies, resilience can no longer be treated as a backup plan. It must be built into the architecture from the very beginning so that mission-critical operations can continue, even when trusted systems become unavailable. That kind of continuity does not happen by accident. It only happens when organizations identify dependencies, plan for failure and build resilience before disruption arrives.
Operational success isn’t determined by how well systems perform under ideal conditions. It’s determined by how well organizations continue executing the mission when things go wrong and long-held assumptions no longer hold true.
About SD3IT
SD3IT (Solution Driven, Designed and Delivered Technology) helps federal and commercial organizations build secure, resilient technology environments through mission-focused IT integration, hyperconverged infrastructure, cybersecurity and operational modernization. We work with customers to design solutions that improve readiness, strengthen resilience and support mission success in an increasingly complex operating environment.
