The True Cost of GPS Denial and the Case for A-PNT Resilience

GPS is so embedded in modern defense operations, commercial shipping, and aviation that it often fades into the background. It is assumed to be constant, accurate, and available, but GPS is not always guaranteed. It can be denied, degraded, jammed, or spoofed, and when that happens, the consequences are rarely limited to navigation problems; the expense can also be paramount.

Globally, over the last few years, there has been an alarming rise in deliberate GPS jamming and spoofing incidents. In 2024, over 1,000 commercial flights a day were affected by GPS spoofing, and in the Baltic Sea and Gulf of Finland, reports of jamming and spoofing incidents in 2025 increased by 127% in a three-month period.

In August 2025, the aircraft carrying European Commission President Ursula von der Leyen experienced GPS jamming over Bulgaria and required backup navigation to land safely. Subsequently, a joint statement from the International Maritime Organization (IMO), International Civil Aviation Organization (ICAO), and the International Telecommunication Union (ITU) warned about harmful interference, including jamming and spoofing, and called for action by Member States to strengthen the resilience of navigation, positioning, and timing systems.

As GNSS and GPS jamming and spoofing become more prevalent, organizations are increasingly operating blind and exposed to cascading costs relating to service disruption, safety hazards, regulatory non-compliance and reputational damage. This has accelerated the case for Assured Positioning, Navigation and Timing (A-PNT), a resilient, layered approach to sustaining trusted timing and positioning when GPS is disrupted. A-PNT can combine multiple independent sources and techniques (satellite, terrestrial, and onboard) to preserve continuity and confidence. Without A-PNT, organizations don’t just lose a signal, they lose confidence, and when confidence disappears, operations slow, costs increase, schedules unravel, and risk rises.

This blog examines the impact of GPS denial, its associated financial implications, and why A-PNT is increasingly viewed as an essential tool for military and defense users, merchant fleets, and aviators who need to maintain safe and predictable movements even when GPS is unavailable.

Uncertainty is a Cost Center

The business case for A-PNT becomes clear when you treat GPS denial as a cost center. Every minute spent slowing down, verifying, rerouting, holding, or diverting is money. Every missed slot, aborted mission, or extended transit is money. Every safety incident, near miss, or compliance failure can be catastrophic in terms of money. If a military unit has to slow or hold position while verifying navigation integrity, it may be exposed longer than planned.

If a merchant ship loses reliable position awareness, it may reroute unnecessarily, increasing transit time and risk. If an unmanned system can’t maintain navigation confidence, it may be pulled from the mission entirely. Every one of these outcomes has a financial expression, whether that’s wasted flight hours, increased maintenance burden, higher fuel usage, or the opportunity cost of assets not being where they need to be. A-PNT reduces these losses by keeping operations predictable under pressure.

Impact of GNSS Degradation in Unmanned Operations

For unmanned operators, GNSS loss or manipulation can translate into constraints and costs within minutes, because GNSS often underpins not just navigation, but also autonomy behaviors (e.g., route keeping, loiter/hold, return to home logic), geofencing and time synchronised data capture. As interference has risen in multiple regions, aviation and maritime safety bodies have issued increasingly prominent warnings about GNSS jamming/spoofing and the need to plan for disrupted environments.

When GNSS is degraded or unavailable, unmanned systems typically shift into more conservative modes: tighter operating areas, lower speeds, increased standoff distances, more manual oversight, or mission aborts. In UAV operations, especially BVLOS and infrastructure / corridor missions, GNSS degradation can also force a reversion to non-GNSS navigation sources (inertial, vision, map matching, etc.) and raise integrity management requirements, because the problem isn’t only position error, it’s whether the system can trust its own PNT well enough to continue safely.

The cost stack for unmanned operations then shows up as lost mission time, rescheduling and re-flight costs, additional personnel oversight, payload / data re-collection, and, at the sharp end, asset loss or third party risk if interference causes navigation faults. In maritime-adjacent unmanned work (USVs and vessels supporting unmanned operations), the same GNSS interference trend is being treated as a growing safety risk, with advisories urging operators to anticipate disruption, report incidents, and implement mitigations.

In time sensitive logistics and security contexts, the margin for error tightens further. Small GNSS-driven slips can break delivery windows, compromise chain of custody or data integrity, and degrade service-level commitments, while in defence and critical infrastructure missions, GNSS degradation becomes a mission assurance and deconfliction risk in contested or degraded environments. That’s why the case for layered A-PNT resilience is strengthening across unmanned platforms: not as a single replacement signal, but as an architecture that preserves confidence through diversity, detection, and graceful degradation.

The Price of Losing Trusted Positioning at Sea

For shipping and merchant fleets, predictable timing is often as valuable as speed. But the most damaging failure mode isn’t always GPS disappears; it’s when crews can’t trust position, course, or time because GNSS is being jammed or spoofed. Industry and security advisories have highlighted corroborated reports of GPS interference affecting vessels in key waterways, including the Strait of Hormuz, and recommend mitigations for navigation planning.

A single collision or contact event driven by GNSS interference can expose shipowners to major third party liabilities, from damage to other vessels and port infrastructure, to cargo loss, pollution response, medical and repatriation costs, and legal defense. These liabilities are typically handled through Protection & Indemnity (P&I) insurance; the mutual liability cover marine operators carry to protect against such claims.

But in a GPS-denied incident, the challenge is not only the size of the exposure, it’s the evidentiary uncertainty. P&I outcomes and recoveries can hinge on being able to demonstrate where the vessel was, what maneuvers were made, and whether it complied with COLREGs, local routing requirements, and port directions at the time of the event. If GNSS interference corrupts, removes, or calls into question the position record, investigations can become slower and more contested, fault can be harder to rebut, and legal costs can escalate, delaying settlement and, in some cases, reducing recoveries.

Beyond P&I liability, GNSS disruption can also show up in war risk pricing, because the same contested corridors where kinetic threats rise are often the places where electronic warfare (including GNSS jamming and spoofing) is part of the operating picture. In the London market, the Joint War Committee (JWC) publishes Listed Areas of perceived enhanced risk, which can trigger additional premium requirements depending on cover and voyage. In periods of heightened Red Sea risk, reported additional war risk pricing rose sharply, moving from low fractions of hull value to figures around the 0.5%-0.7% range by late 2023, with some quotes reported as high as ~1% in peak conditions. For a high-value vessel, that translates into hundreds of thousands to over a million dollars for a single transit before knock on costs are counted.

That’s why A-PNT isn’t just a technical upgrade; it’s a mission/operations enabler. The goal is to retain a trusted position and timing solution even when GNSS is denied, jammed, or spoofed, so crews and operators can keep moving safely with managed risk, rather than defaulting to delay, disruption, or avoidable exposure when the RF environment turns hostile.

Reputation Cost

There’s also a reputational dimension that doesn’t often present itself as a cost center for the cost of GPS denial. Defense organizations are measured by readiness and reliability, commercial fleets are measured by service performance and operational professionalism, and aviation operators are measured by safety and predictability. When GPS denial causes repeated disruptions, customers, partners, and leadership can begin to ask harder questions. The organizations that can demonstrate resilience; the ones that can say “GPS went down and we continued safely and predictably”, are the ones that win trust and contracts.

Resilience Through an Alternative Satellite Network

Iridium PNT delivers a key advantage in degraded GPS environments, chiefly due to signal strength at the receiver. Because the Iridium constellation operates in Low Earth Orbit (LEO) – roughly 25× closer than GNSS satellites in Medium Earth Orbit (MEO) – its downlink can be received at ground level at around 1,000 times (≈30 dB) stronger than traditional GNSS signals.

That higher received power materially improves resilience in the real world: it raises the bar for interference, supports operation in more obstructed environments, and helps sustain trusted timing and position when GNSS is being jammed or manipulated. It complements GPS / GNSS as part of a layered A-PNT approach, restoring operational confidence by providing an independent, authenticated PNT path when GNSS integrity can’t be assumed.

For organizations that require positioning, navigation and timing solutions that can be deployed quickly, the RockBLOCK APNT and RockFLEET Assured devices provide a path to delivering a resilient solution by encapsulating Iridium PNT, without redesigning an entire platform. The devices are built around the reality that fleets and squadrons don’t have the luxury of multi-year integration timelines when the threat – and cost – of GPS jamming, spoofing and denial is already here.

Protecting Time, Revenue, and Reputation

Organizations often underestimate the financial impact of GPS denial because it is rarely captured as a single line item or cost center. Instead, it appears as scattered costs that add up rapidly: additional fuel consumption, extra days at sea, schedule recovery actions, personnel overtime, unplanned port charges, and operational inefficiencies that ripple through multiple departments.

A-PNT is the difference between navigating uncertainty and being governed by it. It reduces the financial impact of delays caused by GPS denial, protects schedules from such cascading disruption, and strengthens safety margins in environments where navigation integrity cannot be assumed.

RockBLOCK APNT and RockFLEET Assured are rugged, reliable, and deployable A-PNT solutions that support continuity of operations by enabling resilient PNT in the field and at sea. For commercial shipping operators, this means more stable ETAs, reduced exposure to costly port and network disruptions and lower AWRPs. For defense operators, it means maintaining tempo, reducing mission risk, and preserving synchronization across assets and units. For drone operators, it means improved navigation integrity in degraded environments and fewer operational compromises when GPS is unreliable. RockBLOCK APNT and RockFLEET Assured exist for the moments when GPS goes dark and the mission, schedule, or flight still has to continue.

How Iridium PNT Can Transform War Risk Insurance for Merchant Shipping

The War Risk Insurance Market is Under Pressure

War risk insurance premiums have skyrocketed in the past two years, reflecting heightened threats in key shipping corridors and merchant vessels navigating unpredictable geopolitical environments.

These premiums, known as Additional War Risk Premiums (AWRPs), are applied on top of normal insurance cover whenever a vessel enters a high risk “Listed Area” defined by the London insurance market’s Joint War Committee (JWC). These surcharges can represent hundreds of thousands, and in some cases millions, of dollars per voyage, dramatically increasing operational costs for carriers.

One example is the Red Sea crisis caused by Houthi attacks in late 2023 and 2024. During this period, war risk premiums for a typical seven day transit of the Red Sea and Bab al-Mandab Strait surged from a nominal 0.05 percent to between 0.4 and 1.0 percent of the vessel’s hull and machinery value.

For a new high value container ship valued at approximately $150 million, this translates into an additional cost of roughly $665,000 per transit. Similarly, a Large Range 2 tanker valued at $105 million faces surcharges of around $420,000, while Very Large Crude Carriers (VLCCs) with insured values near $100 million could see premiums reach $1-2 million for a single high risk seven day transit. These extreme costs, combined with the actual risks of attack, forced major carriers such as Maersk and Hapag-Lloyd to reroute around the Cape of Good Hope, adding 10 to 14 days to their journey and significant fuel costs.

The Black Sea, affected by the Russia-Ukraine conflict, represents another hotspot where war risk insurance costs have surged. The conflict has had significant impact on the grain export corridor. After Russian strikes on foreign vessels, war risk premiums reportedly increased by approximately $125,000 per voyage for a $50 million vessel. In response, insurers collaborated with the United Nations to create specialized grain corridor insurance solutions, enabling essential exports to continue despite elevated risk.

While exact invoices remain private, publicly available market data shows that transiting a war risk area can add a substantial percentage of a vessel’s value to the cost of a short transit. Insurers desperately need reliable, tamper-proof positional data to assess risk, and ships need better protection from spoofing and GNSS interference. That’s where Iridium PNT becomes invaluable.

Why Merchant Shipping Needs A-PNT

The modern maritime industry operates under increasing levels of risk and uncertainty. War risk premiums are fluctuating dramatically, GNSS vulnerabilities are increasing, and traditional tracking solutions leave critical blind spots. In a world where a single transit can cost $500k to $2 million in extra insurance, any technology that enhances trust and reduces risk has immediate economic value.

For shipowners, A-PNT is more than a navigation enhancement. The technology is a financial and operational safeguard, enabling vessels to demonstrate the integrity of their movements and providing insurers with verifiable data that can reduce positional uncertainty. This can translate directly into lower war risk premiums as carriers can prove their routes and positions without ambiguity. By offering immutable, timestamped movement logs that are resistant to spoofing or tampering, A-PNT enables maritime insurers to price risk with confidence and operators avoid unnecessary disputes.

Beyond insurance savings, A-PNT also enhances safety and operational resilience. In high-threat areas, accurate, verified location and timing information is essential for navigation, route optimization, and compliance with safety regulations. Fleet operations centers can maintain situational awareness, even under GNSS interference, while captains receive reliable guidance via A-PNT to avoid hazards or restricted zones. The combination of operational safety and financial prudence positions A-PNT as an essential tool for modern merchant shipping. Ultimately, if ships can prove their track, timing, and location with high integrity – independently of GNSS spoofing and jamming – insurers can price risk with confidence.

Bringing Iridium PNT to the Bridge with RockFLEET Assured

Reliable Navigation for Insurers and Shipowners

With millions at stake in AWRPs alone, Iridium PNT provides a new level of assurance for both insurers and vessel operators. For insurers, the technology reduces exposure to spoofing, improves positioning reliability, and enables more accurate data driven risk pricing. For shipowners and operators, APNT can lower war risk premiums, improve compliance, enhance safety, and ensure operational continuity in high-risk zones.

As the geopolitical risks continue to grow and GNSS vulnerabilities become more frequent, A-PNT is emerging not only as a navigation tool but as a business-critical tracking asset. It allows maritime stakeholders to operate with confidence, knowing that the positional data underpinning insurance decisions, operational planning, and safety compliance is reliable.

In this context, Iridium PNT and RockFLEET Assured represent a transformative solution, providing trusted, validated, and resilient positioning, navigation and timing data that benefits insurers, shipowners, and the broader shipping ecosystem. For stakeholders aiming to reduce financial exposure, enhance safety, and navigate conflict zones with confidence, RockBLOCK APNT is a reliable solution. By enabling a verifiable “source of truth” for vessel positioning, RockFLEET Assured enables more accurate, reliable and cost-effective maritime war risk insurance assessment for modern maritime operations.

Top GNSS/GPS-Denial Questions Answered

Modern military, aviation, and maritime operations are critically dependent on precise Positioning, Navigation, and Timing (PNT) data. For decades, the Global Positioning System (GPS) and other Global Navigation Satellite Systems (GNSS) have served as the backbone of these capabilities, enabling everything from aircraft navigation and drone guidance to vessel tracking and synchronized global communications. However, as GPS denial and deception events become more frequent and geographically widespread, the need for resilient, assured PNT (A-PNT) solutions has become urgent. Ensuring operational continuity requires a clear understanding of the causes of GNSS disruption, who is most affected, how navigation can be sustained without it, and how technologies such as A-PNT can provide protection and redundancy.

The following GPS/GNSS-denial questions outline the key dimensions of this challenge: the sources of GPS disruption, the sectors and regions most exposed, operational fallback procedures, and the A-PNT technologies and strategies designed to safeguard navigation and timing in an increasingly contested GPS environment.

Q1. What Causes GPS Disruption?

Disruption can arise from unintentional interference, deliberate hostile actions, or natural environmental factors; all of which can degrade, deny, or corrupt the signal in ways that directly impact mission assurance and operational safety.

Unintentional interference remains a common source of disruption, particularly in congested environments, like major shipping ports, airspace hubs, and coastal regions. Overpowered or poorly shielded radio frequency transmitters, such as cellular base stations, radar systems, or satellite uplinks, can unintentionally saturate or desensitize GNSS receivers. Faulty amplifiers, including “personal privacy devices” (PPDs) used illegally in vehicles to block tracking, also generate wideband noise that can overwhelm nearby receivers.

Intentional interference, including jamming and spoofing, poses a more severe and rapidly escalating threat. In the military domain, jamming may occur during electronic warfare or combat operations. Criminal organizations also exploit GPS and GNSS vulnerabilities for illicit purposes such as cargo theft, illegal fishing, or sanctions evasion using low cost jammers and spoofers to conceal location or manipulate tracking data. In aviation and maritime operations, such interference can mislead autopilot systems, distort route data, and undermine collision avoidance and surveillance systems like ADS-B and AIS, potentially leading to incidents that pose a threat to life.

Environmental and natural factors further complicate GPS reliability. Solar flares and ionospheric disturbances can alter signal transmission, particularly at high latitudes or during periods of intense space weather, resulting in signal delays or complete loss of lock.  Multipath reflections from large metallic structures, such as port cranes, vessel superstructures, or urban skyscrapers, can also distort signals and create false positional data. These effects are particularly acute in confined environments like harbors or dense airspace corridors, where reflected signals can be mistaken for valid GPS information.

Detection and characterization of GPS/GNSS disruption requires a combination of technical and procedural measures. RF power monitoring and direction finding equipment can help locate the source of interference, while incident mapping and space weather alerts support broader situational awareness. Crowdsourced interference reporting and data sharing between civil and military authorities enhance detection coverage and enable trend analysis across regions.

Q3. How do Pilots, Mariners, and Military Personnel Navigate Without GPS?

In aviation, when GPS is unavailable, aircraft revert to more traditional navigation systems and navigation aids that must be maintained as essential backups. The backbone is the Inertial Reference System (IRS)  and Inertial Navigation System (INS), which uses accelerometers and gyroscopes to continuously estimate position, velocity, and attitude. However, inertial systems suffer from drift – small sensor errors accumulate over time. To constrain that drift, pilots use periodic corrections from ground-based radio aids such as DME (Distance Measuring Equipment), VOR (VHF Omnidirectional Range), or radar updates from Air Traffic Control. When GPS integrity is lost, pilots may revert to conventional airways and non-GNSS instrument procedures, fly under visual flight rules if weather allows, or rely on approaches guided by the Instrument Landing System (ILS), NDB (Non-Directional Beacon), or local ground-based navigation aids. The FAA explicitly retains a VOR MON (Minimum Operational Network) concept to ensure aircraft can navigate via conventional VOR paths during GPS outages.

In maritime and offshore operations, GNSS denial is a severe vulnerability, particularly for dynamic positioning vessels and precise stationkeeping tasks, so ships rely on a suite of fallback systems. A gyrocompass, Doppler log, and radar-bearing fixes provide coarse navigation and heading references in coastal waters. Electronic Chart Display and Information Systems (ECDIS) allow manual plotting of fixes, and in more extended open ocean transits, celestial navigation or celestial fixes remain usable (albeit with skill). Some operators are evaluating the revival of terrestrial radio systems like eLORAN, which transmit low frequency signals over land that are much harder to jam and can serve as a GNSS backup in restricted regions.

For military operations in contested or GPS-denied environments, reliance on GNSS is particularly fragile, so hybrid navigation is essential. The U.S. Army has actively pursued pseudolite networks (ground-based “pseudo-satellites”) to preserve position information when GPS is denied. Pseudolites broadcast local ranging signals that, when integrated with an INS, give troops a reliable local positioning layer with far higher received power than spaceborne signals and therefore much better resistance to jamming at the tactical scale.

These alternative methods, however, are not without vulnerabilities or trade-offs. Inertial systems drift and must be regularly corrected; radio aids can be jammed, degraded, or decommissioned, vision-based systems fail in low visibility or featureless terrain, and acoustic or pseudolite systems have limited coverage or require infrastructure. This is why cross-training crews in traditional navigation techniques, sensor fusion architectures, and frequent calibration of INS and navigation sensors remains essential. Maintaining up to date navigation charts, ground aids, and fallback databases all help to ensure operational continuity when GNSS is degraded or denied.

Q5. How Is Iridium PNT Improving Navigational Resilience for GPS-denied Territories?

For military and security users, this shift offers critical operational advantages. LEO-PNT services delivered via the Iridium constellation provide encrypted and regionally tailored positioning, navigation, and timing data that can penetrate indoors, under canopy, or through moderate jamming. Iridium’s PNT service leverages Iridium’s 66-satellite global mesh operating in the L-band, distinct from GPS frequencies, making it far harder to disrupt with conventional jamming equipment. Because the Iridium system is already operational and uses cross-linked satellites for global coverage, it provides real time assured timing and location integrity even in contested or denied regions such as the Arctic, the Indo-Pacific, or urban RF-dense zones.

Satellite proximity to the Earth and signal strength alone, however, are not enough to secure PNT. Thus, the Iridium PNT service also incorporates cryptographic authentication to protect against spoofing and tampering. Every navigation and timing message is digitally signed, and receiving devices verify the integrity of those signatures before using the data. Unauthorized or falsified signals are rejected, ensuring that systems operate only on trusted information, delivering a far more robust and resilient service than GPS.

For commercial shipping and aviation, these LEO-based services introduce an accessible layer of resilience. In hybrid navigation, Iridium PNT works alongside GNSS and INS, enabling devices such as RockFLEET Assured to seamlessly shift or blend inputs as signal conditions change. In maritime environments, where GPS spoofing has been documented in the Black Sea and Eastern Mediterranean, Iridium-based A-PNT can sustain dynamic positioning operations. Similarly, aviation operators can use A-PNT to maintain flight management system synchronization and prevent false positional data from compromising navigation displays.

In practice, A-PNT serves as a critical additional layer of navigation for military, maritime, and aviation operations, allowing personnel, aircraft, ships, and unmanned systems to maintain mission continuity when GNSS is compromised. The resilient and secure design of A-PNT provides operational assurance, mitigating the single point vulnerabilities of space-based GNSS and GPS navigation, and is increasingly becoming recognized for resilient navigational planning in both defense and commercial sectors.

Q7. What are the Early Warning Signs of GNSS Interference?

Early warning signs of GNSS interference are critical for maintaining operational safety across military, aviation, and maritime platforms. Onboard receivers may show a sudden loss of satellite lock, unexpected position or time jumps, or RAIM/integrity alerts in aircraft, all of which indicate potential jamming or spoofing. Unusually high or low signal-to-noise ratios, discrepancies between redundant receivers, or inconsistencies with INS, radar, Doppler logs, or visual bearings, or an Iridium PNT feed, are additional red flags.

In hybrid GNSS + INS + Iridium PNT architectures, the system can continuously compare GNSS against Iridium PNT’s independent time/location. Divergence beyond thresholds, for example, GNSS position drifting while STL-referenced dead reckoning and ship sensors remain coherent, provides early, positive indication of spoofing or severe degradation, enabling alarms, de-weighting of GNSS, or automatic failover/blending to maintain navigation continuity.

At the system level, automated controls may generate alerts: aircraft autopilots or ship dynamic positioning systems may show deviations from expected performance without an apparent environmental cause. Slowly drifting positions or erratic movements that do not match the platform’s true course may suggest spoofing rather than outright jamming. Environmental indicators, such as unusual RF activity in GNSS frequency bands or corroborating reports from nearby vessels or aircraft, can confirm the presence of interference.

In Summary

The vulnerabilities of GPS and GNSS represent a critical operational risk across military, aviation, and maritime domains. Their inherently weak signals are easily disrupted by intentional jamming, spoofing, or even natural phenomena such as solar flares and ionospheric disturbances. Real world incidents from the Black Sea to the Eastern Mediterranean and Arctic corridors have repeatedly demonstrated that overreliance on GNSS can jeopardize mission integrity, navigational safety, and the continuity of operations. To mitigate these threats, both defense forces and commercial operators should invest in A-PNT to further strengthen resilience by providing high-power, encrypted, and timing and positioning data.

The strategic imperative is clear: GNSS dependence must evolve toward a multi-layered ecosystem, integrating terrestrial and PNT technologies, procedural training, and robust reporting chains. For decision makers in defense, aviation, and commercial shipping, building resilience into PNT infrastructure has become an operational necessity for maintaining control, safety, and strategic advantage in an increasingly contested environment.

Why GPS Isn’t Enough Anymore, And What Lies Beyond

Every time your phone pings “You have arrived”, it’s easy to forget that satellites, atomic clocks and radio beams are doing the heavy lifting. For decades, GPS has been the quiet backbone of modern life, powering navigation, synchronizing telecom networks, and enabling aviation, shipping and defense operations to function effectively. But GPS dependence is starting to look fragile.

Over the last few years, the world has seen an alarming rise in deliberate GPS jamming and spoofing. In 2024, over 1,000 commercial flights a day were affected by GPS spoofing, and this is not an isolated trend. There’s growing awareness that single-source dependence on GNSS/GPS is a strategic vulnerability. The increase of jamming and spoofing incidents has sparked growing concern that GPS manipulation could be exploited for strategic or economic gain, prompting the United Nations to call for stronger safeguards against GPS satellite interference. Aviation, shipping and defense organizations need a practical, deployable alternative now – and a plan for a layered approach in the future – because the real question isn’t if GPS will fail, but what we’ll do when it does.

The Threat of Jamming and Spoofing

Put in simple terms, “jamming” means drowning satellite signals with noise so receivers can’t hear the real thing, and “spoofing” feeds false satellite signals to trick receivers into believing they’re somewhere they’re not.

Deliberate jamming and spoofing incidents are rising in aviation, commercial shipping and defense, and the consequences are no longer hypothetical. In the Baltic Sea and Gulf of Finland, reports of jamming and spoofing incidents rose from 1,225 affected shipping vessels in Q1 of 2025, to more than 5,800 affected vessels in Q2 – a 127% increase. Six years ago, in 2019, commercial vessels operating in Chinese ports around Shanghai, reported widespread GPS anomalies. Ships experienced sudden changes in reported positions, with some appearing to move erratically or vanish from tracking systems. Investigations revealed that these anomalies were due to GPS spoofing attacks which affected hundreds of vessels and disrupted port operations.

Fast forward to this year, and the Nordic and Baltic nations, including Finland, Latvia, Lithuania and Estonia, repeatedly warned about greater electronic interference from Russia disrupting communications with planes, ships and drones. In September of this year, a plane carrying European Union chief Ursula von der Leyen was forced to land in Bulgaria using paper maps after its GPS navigation systems were jammed.

These incidents alone underscore the growing vulnerability of global navigation systems and highlight the need for stronger safeguards against electronic interference in critical transportation and defense sectors.

When GPS fails in Aviation, Maritime and Defense

The Hybrid Navigation Future

With reliance on GPS across aviation, commercial shipping, and defense sectors, concerns about vulnerability to jamming, spoofing, and system outages have driven efforts to explore more resilient navigation technologies. A range of emerging solutions is shaping the future of Assured Positioning, Navigation, and Timing (A-PNT). Each alternative offers strengths and limitations, highlighting the likelihood that the future of navigation will depend on a hybrid mix rather than a single replacement for GPS.

1. Multi-constellation GNSS

Utilizing signals from multiple satellite systems increases redundancy and complicates blanket jamming – but it doesn’t solve targeted spoofing.

2. Inertial navigation systems (INS) and sensor fusion

High-grade inertial measurement units (IMUs) combined with map-matching can bridge gaps for short to medium durations. Classical INS drifts over time however, unless tightly integrated with GNSS to bound drift, and high-performance INS can be expensive.

3. eLORAN (terrestrial low-frequency radio)

eLORAN is a modernized terrestrial radio navigation system that can provide wide area PNT and is much harder to jam at scale. The UK’s Ministry of Defence is focusing its alternative positioning, navigation and timing (Alt PNT) initiative on developing “a proposal for a resilient, terrestrial, and sovereign Enhanced Long-Range Navigation (eLORAN) system to provide backup position and navigation.” In the proposal stage only, the reintroduction and deployment of eLORAN is not currently an active system for GPS resilience.

4. Quantum and advanced sensing

Quantum sensors – notably atom interferometers, quantum magnetometers and other quantum-enabled instruments – can measure motion, gravity or magnetic anomalies with extremely high precision, potentially enabling navigation without satellite signals for hours. Last year, Boeing completed the first recorded flight using quantum navigation systems to navigate across the central United States for four hours without GPS. These technologies are not available outside of testing yet, but could be an option for navigation independent of GPS in the future.

5. Assured Positioning, Navigation and Timing (A-PNT)

Unlike GNSS satellites in Medium Earth Orbit (MEO), Iridium satellites transmit PNT signals from Low Earth Orbit (LEO) that are approximately 1,000 times stronger than GPS signals, allowing them to penetrate buildings and other hard-to-reach areas. The Iridium PNT service also incorporates cryptographic authentication to protect against spoofing and tampering. Thus, unauthorized or falsified signals are rejected, ensuring that systems operate only on trusted information. To harness Iridium PNT, organizations will need compatible receivers, firmware updates and integration with existing PNT stacks. However, that effort is still easier and faster today than building a whole eLORAN network or replacing INS suites.

A Layered Approach for Future GPS Resiliency

GPS reshaped modern life and will remain vital to everyday navigation and positioning, so the right answer isn’t to replace GPS, but complement it with A-PNT. Jamming and spoofing incidents are real, growing, and in some regions, weaponized. The future of resilient navigation is a hybrid one – multiple GNSS constellations, A-PNT, and in the years to come, hardened terrestrial systems like eLORAN and robust inertial/quantum sensors.

From commercial aviation to maritime shipping, military operations to critical infrastructure, reliance on a single GNNS/GPS source exposes organizations to jamming, spoofing, and unexpected interference. The examples of disrupted flights, misreported vessel locations, and spoofed navigation systems highlight its vulnerabilities.

A layered approach to PNT is essential. Among these, Iridium PNT stands out as an immediate, resilient solution. APNT provides critical timing and location integrity that organizations can rely on while building a more comprehensive layered system. Together, those layers can make sure “You have arrived” stays true, even when someone tries to move you off course.

Tackling Maritime GPS Spoofing and Jamming Threats with RockFLEET Assured

One of the most disruptive threats to commercial and military maritime operators is the manipulation of Global Navigation Satellite Systems (GNSS), primarily by low-cost GPS jammers, state-sponsored GPS spoofing campaigns, and cyber-physical interference. From oil tankers seized via spoofed coordinates to cargo ships disappearing from satellite tracking due to jamming, the vulnerabilities of GNSS reliant systems are no longer theoretical, they’re operational hazards. These disruptions compromise navigation, safety, and compliance monitoring, particularly in high-risk regions such as the Baltic Sea, Eastern Mediterranean, and other areas with geopolitical tensions.

GPS Jamming Issue Grows in Eastern Mediterranean and Black Seas
Daily, October 1, 2023 – April 4, 2024

GNSS/GPS manipulation has far-reaching implications, from compromised navigation to operational disruptions. While there are various satellite-based techniques for detecting spoofing and jamming, RockFLEET Assured offers a truly resilient alternative. In this blog, we explore how it works and why it matters.

Key Differences Between Jamming and Spoofing

Spoofing and Jamming Detection via Satellite

Satellite systems can detect GNSS/GPS spoofing and jamming by identifying inconsistencies via a number of indicators and parameters.

Positional behavior can indicate spoofing or jamming. Satellite systems can identify positional and movement abnormalities and send alerts when ships “jump” positions, show physically impossible maneuvers, such as a 90° turn at high speed, or appear in two locations simultaneously, known as ghost ships. Further, comparison with terrestrial radar and sensors is a method of spoofing detection. Satellites compare reported Automatic Identification System (AIS) data with ground radar or visual surveillance, and mismatches may indicate spoofing.

To avoid and prevent spoofing and jamming attacks, commercial shipping companies can support risk-based routing. Here, shipping companies use historical spoofing “heat maps” to reroute vessels around known interference zones, such Baltic Sea, Eastern Mediterranean, and any other region or zone with geopolitical tensions.

These detection techniques are effective, but the vulnerabilities of GNSS/GPS signals remain. A secure and resilient solution is required for complete visibility and confidence of vessel positioning at sea.

How RockFLEET Assured Utilizes Iridium PNT for Jamming-Resilient Maritime Tracking

The technology encapsulated within RockFLEET Assured is designed for easy integration with existing maritime equipment. The device is a single above-deck terminal with no below-deck electronics required, without the optional bridge view, and setup/status are provided via a Bluetooth LE mobile app. RockFLEET Assured is compact, IP67 waterproof – ideal for harsh marine conditions – and features a marine-grade smart antenna that integrates the Iridium PNT module to support A-PNT workflows and Iridium Messaging Transport (IMT) to enable routine position reports.

Purpose-built, RockFLEET Assured is an ideal satellite-enabled, secure and rugged solution for shipping companies to tackle the ongoing threat of GPS spoofers and jammers.

Secure Positioning When GPS Goes Dark

From bulk carriers drifting off-course in the Black Sea to naval vessels being targeted in the Red Sea, GNSS/GPS interference has shifted from a rare anomaly to a strategic weapon. The rise of low-cost jammers, state-sponsored spoofing campaigns, and cyber-physical interference has exposed a serious blind spot in global shipping: overdependence on vulnerable, unprotected GNSS/GPS satellite signals. RockFLEET Assured provides an essential layer of protection, ensuring a secure, resilient, and critical connection to vessels at sea.

With RockFLEET Assured, Ground Control offers a compact, secure, and rugged satellite-based solution that ensures maritime assets stay online, stay located, and stay safe, even when GPS goes dark.