GPS Jamming and the War Over Navigation: What GPSJam.org Reveals About the Middle East Conflict

Key Takeaways

• GPSJam.org tracks GNSS interference via aircraft ADS-B signals, exposing invisible electronic warfare zones globally.
• The 2026 US-Israel-Iran conflict has produced the largest documented GPS jamming event in maritime history.
• Iran’s shift to China’s BeiDou signals a lasting fracture in the global satellite navigation order.

A Map Built From Invisible Signals

On March 18, 2026, the GPSJam.org interference map centered on Tehran showed an unusual condition: incomplete data. The explanation was straightforward in a grim way. With Iranian airspace closed following the late-February 2026 military strikes that began the conflict known as Operation Epic Fury, few commercial aircraft were flying over the country to report GPS accuracy. The very absence of data on a tool designed to detect navigation disruption was itself a form of evidence.

GPSJam.org was created in July 2022 by software developer John Wiseman as a personal project. The tool draws on data provided by ADS-B Exchange, a crowd-sourced flight tracking network maintained by thousands of hobbyist radio enthusiasts around the world. Wiseman built and maintains the site at his own expense, sustaining it through donations, and it has remained free to use since launch.

The timing of the site’s creation was not accidental. Data collection began on February 14, 2022, less than two weeks before Russia’s full-scale invasion of Ukraine, which triggered an immediate and dramatic expansion of GPS interference across eastern Europe and the Black Sea region. What began as a modest open-source side project became, within months, one of the most widely cited public tools for tracking electronic warfare in near real time.

How the Signal Reaches the Screen

Most commercial and general aviation aircraft equipped with transponders broadcast a constant stream of digital messages under a protocol called Automatic Dependent Surveillance-Broadcast, or ADS-B. These messages contain the aircraft’s position, speed, heading, and a set of accuracy parameters describing how well the onboard navigation system is performing at that moment. The parameter GPSJam.org depends on most heavily is NACp, which stands for Navigation Accuracy Category for position. It encodes whether the aircraft’s positioning system is within acceptable bounds or has degraded significantly.

When a Global Navigation Satellite System receiver aboard an aircraft encounters interference, the NACp value drops. The Federal Aviation Administration considers any NACp value below 8 to be non-compliant for standard operations. GPSJam.org aggregates 24 hours of NACp reports from all aircraft transiting a given geographic zone, then displays the results using a hexagonal grid. Green hexagons indicate that fewer than 2% of aircraft in a zone reported degraded accuracy. Yellow hexagons indicate that between 2% and 10% reported problems. Red hexagons indicate that more than 10% reported degraded accuracy.

The formula Wiseman applies is not a simple average. It subtracts one aircraft from the degraded count before dividing, a deliberate de-noising step designed to reduce the chance of a single malfunctioning transponder coloring an entire hexagon red. The result is a system skeptical about small samples but fast to respond when large numbers of aircraft across a region simultaneously report problems.

There are real limits to this approach. Because the tool depends on commercial flight activity, it cannot report on areas with no civilian air traffic. Conflict zones where airspace has been closed, large ocean expanses with no regular routes, and parts of the world where few ADS-B receivers exist all appear as blank space. The airspace over active war zones is often the most intensely jammed, and it is exactly the airspace that yields the fewest aircraft reports. The map is most blind where the problem is most severe.

What the Tehran View Shows

The specific GPSJam.org URL centered on coordinates approximately 35.74°N, 51.26°E at a regional zoom level on March 18, 2026 captures a moment of layered disruption. The airspace over Iran is functionally closed to commercial traffic following the February 28, 2026 strikes that opened the current conflict. That closure means the hexagonal grid in the immediate vicinity of the Iranian capital shows nothing at all, because there are no aircraft to report anything.

The regions surrounding Iran tell a different story. Data collected from aircraft transiting the Persian Gulf, the Gulf of Oman, and the Arabian Peninsula before and during this period showed extensive red and yellow coverage, indicating that large proportions of aircraft in those zones reported navigation degradation. The GPSJam.org data for the days immediately preceding March 18 aligned with what maritime tracking services independently confirmed: a massive, expanding zone of GPS interference centered on the Strait of Hormuz and the waters of the Gulf states, with disruption spreading further up the peninsula than had been recorded in any previous conflict.

Jamming and Spoofing Explained

GPS, the American-operated satellite navigation system, functions by broadcasting precisely timed radio signals from a constellation of satellites orbiting at roughly 20,200 kilometers altitude. A receiver on the ground, at sea, or in the air calculates its position by measuring the tiny difference in arrival times from at least four satellites. The signals are extraordinarily weak by the time they reach Earth, having crossed the vast gap from orbit.

That weakness is the root of the vulnerability. A device broadcasting a stronger signal on the same radio frequencies can overwhelm the satellite signal entirely. This is jamming: the navigation receiver hears noise instead of satellite signals and loses its ability to compute a position. The effect is local. Jamming does not alter the satellite signal itself; it simply shouts over it within a limited radius. Most ground-based jammers affect an area of a few kilometers to a few tens of kilometers, and devices capable of producing this effect are commercially available for prices ranging from $130 to $2,000. Military systems can extend interference across far wider zones, particularly at altitude where aircraft have clear lines of sight to ground-based interference sources spread across a wide area.

Spoofing is technically more involved and operationally more dangerous. A spoofing device generates false satellite signals that a receiver accepts as genuine. The receiver then computes a position that is wrong but that it believes to be accurate. Ships and aircraft experiencing spoofing may not generate any warnings. Their systems believe they know exactly where they are, while their displayed position is somewhere entirely different, sometimes at airports, sometimes inland, sometimes hundreds of kilometers off course. Maritime tracking services documented dozens of vessels in the Persian Gulf being shown at inland locations, at airports, and near a nuclear power plant during the early days of the current conflict, each instance a result of active spoofing rather than jamming.

The distinction matters for safety. Jamming causes a receiver to fail visibly. Spoofing causes it to fail silently. A ship captain who knows the navigation system has been lost can switch to backup systems and proceed with heightened caution. One whose instruments show a confident but false position may act on that false information in ways that create real danger.

The Conflict That Rewrote the Map

GPS interference in the Middle East predates the current conflict by several years. During the Gaza operations of 2023 and 2024, aviation monitoring showed persistent GPS degradation across Lebanon, northern Israel, Cyprus, and parts of the eastern Mediterranean, attributed by analysts to Israeli military electronic warfare systems operating defensively against drone and missile attacks. The pattern was already established well before 2026: modern drone warfare has made GPS denial a standard tool of both offense and defense.

The 12-day war between Israel and Iran in June 2025 marked a significant escalation. During that conflict, maritime tracking services documented nearly 900 vessels in the Strait of Hormuz and the Persian Gulf experiencing navigation signal disruption. The Iranian port of Bandar Abbas was identified as a probable source of interference affecting surface shipping. That conflict ended in a ceasefire, but the electronic warfare infrastructure deployed during it remained in place.

When Operation Epic Fury began on February 28, 2026, with American and Israeli strikes on Iranian territory, GPS disruption escalated far beyond anything previously recorded. Within 24 hours of the opening strikes, maritime analytics firm Windward documented more than 1,100 vessels experiencing GPS and AIS interference across the Persian Gulf. By March 7, that figure had risen to more than 1,650 ships, a 55% increase in under two weeks. Windward identified at least 30 distinct jamming clusters across the waters and territories of Saudi Arabia, Kuwait, the UAE, Qatar, Oman, and Iran, with patterns that shifted from circular crop-circle formations in the first days to zig-zag lines spreading across the Gulf of Oman and beyond.

The Maritime Dimension

The Strait of Hormuz is one of the world’s most constrained and consequential maritime chokepoints. At its narrowest, the waterway measures roughly 39 kilometers across. Approximately one-fifth of the world’s oil and gas exports transits it, channeled through a passage flanked by Iranian territory on one side and Omani territory on the other. Precise positional awareness in that space is not a convenience. It is a safety and legal necessity in waters where the boundary between Iranian, Omani, and international zones shifts within kilometers.

GPS interference in and around the strait created conditions that navigation experts described as extremely hazardous. Ships falsely positioned by spoofing signals could not accurately judge their distance from other vessels, hazards, or territorial limits. The danger of collision increases sharply when multiple ships in a confined waterway are each operating on different, erroneous position readings, with no common accurate picture of the traffic around them. A June 2025 collision between the tankers Adalynn and Front Eagle off the UAE coast was assessed by navigation experts as likely connected to electronic interference, though the investigation did not reach a formal conclusion before the current conflict began.

Traffic through the strait approached a near standstill by mid-March 2026. Maritime data showed only a handful of outbound transits per day during the second week of the conflict, with almost no inbound crossings. Some vessels re-routed through Iranian territorial waters after Iranian authorities appeared to selectively permit passage for certain ships, primarily those connected to Iran-affiliated trade or particular national flags. Seafarers’ organizations estimated roughly 40,000 merchant sailors were effectively trapped, either inside the Gulf unable to exit, or outside, unable to enter port to complete voyages.

The economic effects extended far beyond the region. Benchmark tanker earnings in the Middle East reached levels approximately $200,000 per day above pre-conflict rates. Insurance premiums for vessels willing to attempt a strait transit rose sharply. Energy prices spiked across markets dependent on Persian Gulf exports, and analysts flagged early signs of fertilizer cost increases tied to natural gas derivatives, threatening food security in import-dependent countries.

Aviation Under Electronic Interference

Aircraft flying routes across the Arabian Peninsula and the approaches to Gulf airports encountered GPS problems beginning on February 28, 2026. Swiss navigation analytics firm SkAI Data Services tracked disruptions from that date, noting that even the minimal traffic remaining in the region, rerouted south through Oman and Saudi Arabia, showed a large proportion of aircraft affected by spoofing. On March 2 alone, data from SkAI indicated that at least 169 aircraft flying over the eastern Arabian Peninsula were hit by spoofing.

Interference at altitude presents particular problems because aircraft at cruising height have clear line-of-sight to interference sources that ground receivers might never detect. A jammer or spoofer operating from a coastal installation can affect aircraft over a wide geographic area at the same time. Pilots encountering GPS failures are trained to revert to alternative systems, including VOR beacons and inertial navigation systems, but those systems require additional workload, and inertial navigation accumulates drift error over time that compounds during long flights.

Flightradar24, one of the major public flight tracking services, has addressed GPS jamming’s effect on position data by switching to multilateration (MLAT) positioning when GPS-derived ADS-B reports are unavailable. MLAT uses time-difference-of-arrival calculations from multiple ground stations to track aircraft independently of satellite navigation. That workaround depends on ground station coverage, which is not uniform globally and is most sparse over the same conflict zones where jamming is most intense.

The FAA’s GNSS interference resource guidance for pilots makes clear that when GPS is jammed, ADS-B position broadcasts become unreliable or stop entirely, because ADS-B depends on GPS for positional data. This creates a feedback loop in conflict zones: the same electronic warfare that disrupts aircraft navigation also degrades the flight tracking data that tools like GPSJam.org depend on to report the interference.

Iran’s Navigation Divorce

One of the most strategically significant developments to emerge from the electronic warfare environment of the past year is Iran’s formal abandonment of GPS for domestic use. During the June 2025 conflict, GPS disruption affected Iranian military and civilian systems across multiple provinces, with Iranian officials attributing the interference to American and Israeli electronic warfare activity. On June 23, 2025, Iran formally deactivated GPS reception nationwide and completed a transition to BeiDou, China’s satellite navigation system.

The move had been in preparation for years. As early as 2015, Iran and China signed a memorandum of understanding covering BeiDou integration, including ground reference stations and a space-data collection facility on Iranian territory. The 25-year Iran-China Comprehensive Strategic Partnership formalized in 2021 gave Iran access to BeiDou’s military-grade signals, a level of access typically reserved for China’s closest strategic partners.

BeiDou operates more than 50 satellites across three orbital configurations: geostationary, inclined geosynchronous, and medium Earth orbit. That structural diversity provides stronger signal geometry in regions at certain latitudes, including much of the Middle East, and delivers higher redundancy than GPS alone. For Iranian military planners, the transition reduces the risk that GPS denial by adversaries disrupts drone guidance and missile navigation. Iranian drones such as the Shahed design already incorporate inertial navigation systems that operate without GPS during flight, connecting to positioning signals only briefly before or after launch, precisely to survive the GPS jamming that any defended target will likely employ.

The available evidence supports a clear analytical position here: Iran’s GPS denial operations in the Strait of Hormuz are deliberate, directed specifically at surface shipping, and designed to constrain maritime traffic through the waterway as a strategic pressure instrument, while Iran itself operates on a navigation architecture that is immune to GPS interference. US and allied jamming in the same region serves a different function, primarily defensive protection of military assets and personnel from drone and guided-weapon attacks, but the commercial and civilian collateral damage from both sets of operations falls on the same ships, the same aircraft, and the same communities dependent on working navigation systems. The interests doing the jamming are symmetrically indifferent to those costs.

Who Else Is Jamming

The Middle East is the most acute current example, but far from the only persistent GPS interference zone that GPSJam.org has documented since 2022. The Black Sea region has shown near-constant jamming and spoofing since the opening of the Russia-Ukraine war, with interference affecting airspace over Romania and Bulgaria and, at times, commercial flights across the eastern Mediterranean. The Baltic Sea region has seen regular GPS degradation across airspace over Poland, Lithuania, Latvia, Estonia, Finland, and Sweden, with most European governments attributing the events to Russian electronic warfare. Even parts of Germany have been affected.

Parts of South Asia also show interference correlating with drone warfare. Areas around Lahore, Pakistan and Yangon, Myanmar appear on the GPSJam.org map with some regularity. In the United States, the southwestern region, particularly parts of Texas, shows interference that Wiseman’s site explicitly identifies as non-conflict-related: military trainer aircraft executing high-G maneuvers that temporarily block their own GPS antennas from satellite visibility. That effect appears identical to jamming on a hexagonal grid but reflects aircraft geometry rather than any ground-based interference source.

The proliferation of GPS jamming across so many distinct theaters reflects a structural reality in modern conflict: GPS-guided drones are now standard tools at every level from state militaries down to non-state actors, and disrupting GPS is among the primary defensive responses available. Ukraine’s documented electronic neutralization of thousands of attack drones through jamming and spoofing in 2025 illustrates how effective the technique can be when deployed systematically at scale.

The Limits of Open Signals

The commercial GPS signal was never designed with security as a primary feature. It broadcasts openly, without encryption, on publicly known radio frequencies. The signal strength arriving at Earth from GPS satellites is extraordinarily faint, requiring highly sensitive receivers to detect. That sensitivity makes them easy to overwhelm with a stronger competing signal.

Until recently, only military GPS signals carried meaningful security features. Since 2024, Europe’s Galileo system has offered a signal authentication capability allowing receivers to verify that signals have not been tampered with, a technology referred to as Open Service Navigation Message Authentication. The U.S. GPS modernization program includes plans for similar authentication on next-generation civilian signals. Existing satellites and the hundreds of millions of receivers already deployed globally cannot be upgraded retroactively, meaning the transition to authenticated signals will take decades even under the best conditions.

Analysts in navigation security have drawn comparisons to the history of wireless networking. Early Wi-Fi networks broadcast openly with no encryption, a design that seemed unremarkable when the technology was new and became untenable as the networks became universally relied upon and adversaries learned systematically to exploit them. The same progression appears underway with satellite navigation, except the stakes involve ships carrying millions of barrels of oil, aircraft with hundreds of passengers, and precision weapons with strategic consequences.

Whether the regulatory frameworks and procurement mandates to push authenticated civilian signals into widespread adoption can be assembled before the next major maritime accident in a jammed waterway remains genuinely open. No international agreement currently mandates authenticated GNSS receivers for commercial shipping. No regulatory body has set a hard deadline for phasing out receivers that cannot detect spoofing. The technical tools are advancing. The governance structures that would deploy them at scale are not keeping pace, and that gap is exactly where the next avoidable disaster will be located.

Summary

GPSJam.org was built as a hobby project by one developer and became an indispensable public intelligence resource. The incomplete data it displays for the Tehran region on March 18, 2026 is a footnote to a larger event: a conflict that has produced the largest documented GPS interference event in maritime history, reduced traffic through the world’s most consequential energy corridor to near zero, and accelerated a permanent realignment in which navigation signals reach which territory. The blank hexagons over Iran are not a data gap. They are a consequence, made visible by the absence of the aircraft that once routinely crossed that airspace.

What the current crisis has made difficult to dispute is that satellite navigation systems built on open, unencrypted signals cannot function as neutral civilian infrastructure in a world where military GPS denial is a reflex response to drone warfare, where state actors have reason to deploy interference across entire ocean corridors, and where a device capable of disrupting navigation for everything nearby can be purchased online for less than the cost of a tank of fuel. The authentication technologies needed to harden civilian navigation against spoofing exist in prototype form today and in limited deployment in Galileo. The path from limited deployment to the universal adoption required to protect the Strait of Hormuz and the hundreds of other waterways, runways, and shipping lanes that share this vulnerability runs through political decisions that no conflict has yet forced governments to make.

Appendix: Top 10 Questions Answered in This Article

What is GPSJam.org and how does it work?

GPSJam.org is a free, publicly accessible website created by developer John Wiseman in July 2022. It generates daily maps of likely GPS interference by aggregating navigation accuracy data broadcast by commercial aircraft, using data from the ADS-B Exchange network of volunteer radio receivers. Hexagons on the map are colored green, yellow, or red based on what percentage of aircraft in a given zone reported degraded navigation accuracy during a 24-hour period.

Why does the GPSJam.org map show incomplete data for Iran on March 18, 2026?

The site requires aircraft flying through an area to generate data. With Iranian airspace closed following military strikes that began on February 28, 2026, few commercial aircraft were transiting the region, leaving blank hexagons over Iran itself. This absence reflects the conflict’s impact on civilian aviation rather than a malfunction in the tool, and is itself evidence of the scale of the disruption.

What is the difference between GPS jamming and GPS spoofing?

Jamming floods a GPS radio frequency with noise, preventing receivers from detecting satellite signals and causing the receiver to report a visible failure. Spoofing generates false satellite-like signals that a receiver accepts as genuine, producing a plausible but incorrect position without triggering an obvious warning. Spoofing is considered more operationally dangerous because ships and aircraft can act on false positional data without knowing anything is wrong.

How many ships were affected by GPS interference during the current Iran conflict?

Maritime analytics firm Windward documented more than 1,100 vessels experiencing GPS and AIS interference within 24 hours of the opening strikes on February 28, 2026. By March 7, that number had risen to more than 1,650 ships, a 55% increase in under two weeks, with at least 30 distinct jamming clusters identified across the Persian Gulf and Gulf of Oman region.

What is the NACp parameter and why does GPSJam.org use it?

NACp, or Navigation Accuracy Category for position, is a field in the ADS-B digital broadcast that aircraft transmit continuously. It encodes how accurately the onboard navigation system is performing at any given moment. The FAA considers any NACp value below 8 to be non-compliant for standard operations. GPSJam.org interprets a drop from high NACp values to near-zero as evidence that an aircraft’s navigation system has been disrupted.

Why did Iran switch from GPS to China’s BeiDou system?

During the 12-day Israel-Iran war in June 2025, GPS disruption affected Iranian military and civilian systems across multiple provinces. Iranian officials attributed the interference to American and Israeli electronic warfare. On June 23, 2025, Iran formally deactivated GPS reception nationwide and completed a transition to BeiDou, building on cooperation with China that had been in place since a 2015 bilateral agreement and formalized under the 2021 Iran-China Comprehensive Strategic Partnership.

Where are the other major GPS interference zones documented by GPSJam.org?

Beyond the Middle East, GPSJam.org regularly shows interference in the Black Sea and surrounding areas including Romania and Bulgaria, the Baltic Sea region affecting multiple NATO member states, and parts of South Asia around Lahore and Yangon. The southwestern United States, particularly parts of Texas, also shows interference attributed to military training aircraft maneuvers rather than ground-based jamming.

What are the maritime safety risks of GPS interference in the Strait of Hormuz?

The Strait of Hormuz is roughly 39 kilometers wide at its narrowest point and carries approximately one-fifth of the world’s seaborne oil and gas exports. Jamming and spoofing in this confined waterway increase collision risk by giving ships false or absent positional data, making it impossible for vessels to accurately judge their distance from each other or from territorial boundaries. Navigation experts assessed a June 2025 tanker collision off the UAE coast as likely connected to electronic interference.

How does ADS-B Exchange contribute to GPS interference mapping?

ADS-B Exchange is a crowd-sourced flight tracking network maintained by thousands of hobbyists worldwide who use radio receivers to capture and relay aircraft digital broadcasts. Unlike commercial flight tracking services that filter data in various ways, ADS-B Exchange shares unfiltered data, making it a preferred source for open-source analysis. John Wiseman uses the ADS-B Exchange API to collect and process aircraft NACp values and build the GPSJam.org hexagonal maps.

What technical changes could make GPS more resistant to jamming and spoofing?

Europe’s Galileo system introduced a signal authentication capability in 2024, called Open Service Navigation Message Authentication, that allows receivers to verify signals have not been tampered with. The U.S. GPS modernization program includes plans for similar civilian authentication on next-generation satellites. However, existing satellites and the hundreds of millions of receivers already in use worldwide cannot be upgraded retroactively, meaning meaningful protection will require new receiver mandates and regulatory action across multiple industries.