Executive Summary
Russian electronic warfare from the Kola Peninsula disrupted GPS tracking at Finnmarksløpet, Europe's longest sled dog race, forcing organisers to rely on traditional navigation. The 1,200-kilometre race across northern Norway – particularly near Kirkenes and the Pasvik valley – became a visible demonstration of GNSS vulnerability. For offshore survey managers, this incident confirms what many already suspected: satellite positioning in contested or interference-prone regions cannot be treated as reliable infrastructure. We examine what this means for construction survey, as-built verification, and dynamic positioning operations where GNSS forms the foundation of the positioning solution.
What Happened
Russian electronic warfare systems stationed on the Kola Peninsula disrupted the Finnmarksløpet, a 1,200-kilometer dogsled race in northern Norway. Interference and manipulation of GNSS signals severely affected the GPS devices of individual teams. As a result, location data was lost, positions changed, and data even became invalid on publicly available maps. Tarjei Sirma-Tellefsen, chief of staff of the Finnmark Police, confirmed that GNSS interference was a problem throughout the race area, and the police, unsurprisingly, were in constant contact with the organizers to ensure the safety of the participants. The race route winds eastward from Alta across the Finnmark Plateau to Kirkenes, less than 10 kilometers from the Russian border. Part of the route runs through the Pasvik Valley, along the river that separates Norway and Russia. The teams are thus in the heart of a region that has been subjected to systematic interference since 2017. We’ve seen it before. This isn’t an isolated incident. Pilots landing at Kirkenes and other airports in northeastern Norway report GNSS interference almost daily. Finland and Estonia have raised the alarm, blaming Russian and Belarusian sources for the persistent disruptions in the Gulf of Finland. This race for dominance has become a public and striking example of what our aviation and maritime experts have long known: satellite positioning in the High North and the Baltic Sea is unreliable.
Why This Matters
Most maritime positioning systems treat GNSS like electricity – it simply has to work. We plan for equipment failures, not just signal loss. Dynamic Positioning Systems (DPS) consider themselves safe with three GNSS receivers. Surveying instruments assume that DGPS or PPP will provide decimeter-level positional accuracy, weather permitting. This is something to keep in mind. And when risk assessments mention “satellite communication failure,” it’s dismissed as a short-term nuisance (yes, really!), not a mission-threatening nightmare. Finnmarksløpet completely changed the picture. For days, GNSS proved to be unreliable infrastructure. They were forced to rely on physical markers and old navigation methods like distance measurement, or simply by following their own path. Sure, that might work for dog sleds traveling at a leisurely 15 km/h. But seriously, that wouldn’t work for pipelay vessel held in place by a 2-knot current, or for a construction pontoon anchored over a template in 80 meters of water. You see, this also highlights a serious planning error we see time and again in our industry: We assess GNSS risk based on satellite geometry, atmospheric conditions, and equipment specifications, without asking the critical question: Will there even be a signal? Norwegian authorities now refer to GNSS problems in East Finnmark as the “new normal” and, given the deteriorating satellite navigation, emphasize the need for long-term planning. So, how many offshore positioning plans today account for a long-term signal outage? Probably very few.
The Reality on Deck
Let’s consider a real-world maritime survey scenario. Typical situation: You’re conducting as-built survey in the Barents Sea, 200 kilometers north of Hammerfest, aboard a vessel. Six GNSS receivers are available: two for dynamic positioning, two for positioning during the survey, and two for RTK corrections. A dual-frequency multi-constellation system (GPS, GLONASS, Galileo, and BeiDou) is in use. Your FMEA (Failure Mode and Effects Analysis) identifies GNSS as redundant – with an inertial backup and an acoustic backup sensor for emergencies. Then, problems occur. All six receivers lose signal simultaneously. Why? They’re all receiving the same unreliable source. Your IMU (Inertial Measurement Unit) can transmit position data for a maximum of 20 minutes before drift becomes a serious survey issue. The acoustic sensor activates – it shows the ROV’s position relative to the vessel. But where is the vessel relative to the pipeline? You’re stuck – why? This isn’t a hardware failure, but simply interference 100 kilometers away. The fallback options listed in your positioning plan—“Continue operating with alternative systems until GNSS is restored”—are designed for rapid recovery within minutes or hours. The unusual thing is, in Finnmarksløpet, this phenomenon persisted for several days and extended over several kilometers, and pilots in East Finnmark are complaining about interference daily. When will “Waiting for restoration” finally become “This isn’t going to happen anytime soon”? For two decades, maritime positioning has been optimized for GNSS. DGNSS baselines have been extended, and why not? The low density of acoustic networks is explained by the fact that GNSS enabled precise ship positioning. The coverage areas of dynamic positioning systems have shrunk because satellite positioning offered a combination of low cost, accuracy, and reliability. This is truly alarming. But when GNSS fails, your supposed optimization collapses. It’s a vulnerability, not an advantage.
Where Clients Get It Wrong
1. Treating GNSS Denial as Equipment Failure
We’ve seen this before: plans that equate ” GNSS loss” with “receiver failure” or “antenna damage.” The instinctive reaction is the same: switch to a backup receiver. Ideal if only one receiver fails, but useless if the signal itself is distorted. Signal interference and manipulation make no difference – they affect all receivers, since they all receive signals from the same distorted source. Six or three receivers – it makes no difference; it’s merely perceived redundancy. Yet, GNSS is listed as redundant in FMEA reports based on the number of receivers, ignoring the obvious possibility of failure.
2. Assuming Interference is Transient
Emergency plans often treat GNSS outages as temporary phenomena – solar storms, satellite problems, nearby disturbances that will soon resolve themselves – and therefore recommend: “Wait and see with backup options” or “Pause until the situation returns to normal.” This may suffice for short-term disruptions. But not for persistent, deliberate disruptions affecting an entire area. A Norwegian report on GNSS disruption in East Finnmark? Persistent, predictable. Pilots there use ground-based and inertial navigation as their primary solutions, not as backups. This isn’t just another disruption; it’s the new normal. Maritime plans based on short-term disruptions will quickly reach their limits under such conditions.
3. Ignoring Geographic Risk Patterns
Finnmarksløpet wasn’t just taking a risk; it’s a known problem area. GNSS issues in this region have been discussed since 2017. There’s no room for compromise. Reports from the Barents Observer, statements from the local police, and official confirmations document a history of interference. Yet, research plans are being proposed for the Barents Sea that rely solely on satellite geometry and atmospheric models, ignoring electronic warfare and the history of regional interference. Geographic patterns are not merely guidelines. The Kola Peninsula is littered with military equipment; GNSS outages occur regularly in the Baltic Sea, disrupting shipping in the Gulf of Finland. The same is true for the eastern Mediterranean. To operate in these areas without considering the history of signal interference is reckless behavior disguised as optimism.
4. Over-Relying on Multi-Constellation Receivers
GPS, GLONASS, Galileo, BeiDou – modern receivers use all these satellites, and we’re proud of this diversity. GPS interference? No problem, GLONASS will step in – or Galileo if GLONASS fails. but In practice, interference prevents you from focusing on just one satellite constellation at a time. Broadband interference destroys all GNSS signals; signal manipulation can lead to the simultaneous propagation of incorrect signals across multiple satellite constellations. Multi-satellite receivers improve position data under interference-free conditions; however, they don’t protect against deliberate interference. While your receiver can receive more satellites, disrupted or manipulated signals mean more data clutter. ## What Survey Managers Should Actually Do
Before you even consider flying into the Barents Sea, Norwegian waters, or the Baltic Sea, conduct a geographic risk analysis. What is the history of interference in these areas? Review GNSS alerts (yes, really!) issued by aviation authorities, maritime authorities, and the coast guard. If pilots are initially switching to inertial navigation due to unstable GNSS, simply deploying six GNSS receivers is not enough. It’s insufficient. Also, ask yourself: Can we even determine our minimum positioning accuracy without GNSS? If you believe that relying solely on inertial navigation will suffice, how long can you maintain that accuracy? What about an independent acoustic network on the seabed? Is it dense enough to cover you? Do you have rangefinders or microwave positioning systems that don’t rely on satellites? Don’t wait until all your receivers fail simultaneously to address this issue. Some operations simply cannot be performed in areas without GNSS. Pipeline installation, for example, requires continuous positioning with decimeter accuracy over long distances. As-built demands precise, reproducible coordinates referenced to the same geodetic point. Relying solely on GNSS in known interference areas? That’s pure wishful thinking. That’s not risk management, it’s wishful thinking. Customers and regulators need to be pressured to realistically assess the problems. The IMCA positioning guidelines treat GNSS outages as minor disturbances. The IOGP discusses technical failures but only briefly addresses the problem of sustained signal loss. The IHO standard S-44 assumes satellite positioning always works. In reality, these guidelines don’t account for situations where signals are unstable for days across large areas. We need new guidelines for this complex reality.
The Bigger Question: Resilience or Redundancy?
For three decades, the offshore industry has been investing in GNSS redundancy: entire receiver arrays, multiple frequencies, entire satellite constellations. The brochure gives the impression that this is sufficient in the event of equipment failure. But Finnmarksløpet has impressively demonstrated this: it’s about dependence on infrastructure. More receivers are useless if the signal suddenly drops. Reliability means maintaining the functionality of the equipment even under drastic environmental changes. This requires diversifying positioning methods – combining GNSS, inertial measurement, acoustic, and distance measurement systems. For this, it’s necessary to identify geographical risks early and face the hard truth: some operations are impossible without GNSS. Take dog sled racing as an example: what happens then? The reliance on signposts and traditional navigation increases. Offshore solutions? Dense acoustic networks, tripwire systems, laser positioning. Yes, it’s more expensive and slower, but what happens if the satellites fail? The job can still be done. Otherwise, as with Finnmarksløpet, the tracking system displays incorrect, exaggerated coordinates. And you’ve put everything on hold because your entire plan relied on consistently reliable satellites. That’s a planning error, not just a technical one.
What This Means for Your Next Barents Sea Job?
Are you preparing for operations in GNSS problem areas like the Barents Sea or the Norwegian Sea within 300 kilometers of the Kola Peninsula? Your positioning plan should be designed to avoid prolonged GNSS signal outages. This includes: identifying satellite-free positioning options; estimating the duration for which inertial systems can maintain geodetic accuracy; developing a strategy for configuring acoustic networks for independent positioning; identifying critical points where continued operation becomes uncertain; and budgeting for long-term operations with backup systems. Ignore these points and simply assume that GNSS will work flawlessly. Seven years of hard work in the Baltic Sea and the experience of the Finnmarksløpet clearly demonstrate that this is a mistake. Those vessels surrendered, adapted, and won. Now it’s up to us, dear survey managers: Do we improve our planning before the next ship sinks and is caught unprepared during critical operations, or do we continue to pretend that GNSS is absolutely reliable everywhere? We know the answer. The question is whether our customers – and their plans – understand it.
Based on: GNSS jamming spills over into Europe’s longest sled dog race
