A powerful GPS jammer capable of disrupting satellite navigation signals across parts of Sofia has been located and neutralized in the capital's Dragalevtsi district in a joint operation involving the State Agency for National Security, the Communications Regulation Commission and the Interior Ministry's State Security Service.
According to the State Agency for National Security, the device was suppressing GPS frequencies across Sofia, including the area around Vasil Levski Sofia Airport, aircraft flying over the capital and television towers. The discovery has raised concerns about the potential impact of GPS interference on aviation and other critical systems that rely on satellite positioning and timing.
The Sofia airport, however, said its operations were not affected and that flights were being handled according to schedule. Bulgarian National Radio reported that there had been recent problems with GPS signals affecting aircraft taking off and landing in Sofia, although the publicly available information does not establish that these disruptions were caused by the device found in Dragalevtsi.
The technical capabilities of the jammer cannot be determined simply by describing it as powerful. Its actual impact would depend on factors including its transmission power, operating frequencies, antenna configuration and the measured range of the interference.
GPS is part of the broader family of Global Navigation Satellite Systems, which provide positioning, navigation and highly accurate timing. Satellites transmit very weak signals to Earth, and receivers use them to calculate location, speed and time.
A jammer does not disable satellites. Instead, it generates radio-frequency interference that can overwhelm the satellite signal in a particular area, potentially preventing receivers from obtaining a reliable navigation solution. This differs from spoofing, in which false signals are transmitted to make a receiver calculate an incorrect position or time.
Such interference is particularly relevant to aviation because GNSS is used for navigation, positioning and timing, as well as in various systems connected with air traffic management and monitoring. If the interference is strong enough, an aircraft receiver may lose the GNSS signal or switch to alternative navigation sources and procedures.
That does not automatically mean that aircraft become uncontrollable. Modern aviation relies on backup navigation systems and established procedures for situations in which a particular navigation source becomes unavailable. In this case, there is no public evidence of an aviation safety incident involving a specific flight, while the airport has said that its operations continued normally.
The significance of GPS extends well beyond aircraft. Accurate satellite timing can be used to synchronize telecommunications networks, energy systems, transportation technologies, financial systems and other infrastructure. A sufficiently broad interference zone could therefore affect systems that rely on GNSS for positioning or synchronization.
There is currently no public evidence that the Dragalevtsi device caused disruptions to critical infrastructure. Its actual range and technical characteristics have not been disclosed.
GPS jamming also has military applications because armed forces depend heavily on positioning, navigation and timing capabilities. Interfering with these signals can complicate navigation, coordination and the operation of various systems without physically attacking a target.
That broader military application, however, does not establish that the Sofia jammer was connected to a military or intelligence operation. The authorities have not publicly identified its owner, operator or purpose.
Unofficial reports have linked the discovery to a heavily guarded complex in Dragalevtsi. Bulgarian National Radio and other media reported that the device may have been found at a Greek restaurant associated with a 2023 incident involving the notorious former investigator Petyo Petrov, known as "Petyo The Euro". Petrov escaped during an attempted detention and was never apprehended at the location. The restaurant has continued operating, while police and gendarmerie have reportedly maintained a presence in parts of the complex.
The institutions have not officially confirmed who owned or operated the jammer, how long it had been active or why it was being used. A restaurant manager, Angel Yordanov, told Nova TV that he had been informed by police that a device had been found but questioned whether it was actually inside the restaurant, saying "It could be a kilometer away from us."
One possible explanation raised by former deputy rector of the Academy of the Interior Ministry Milen Ivanov is protection against drone attacks. He said the characteristics of the device could fit a scenario in which people in the area wanted to prevent drones from operating accurately.
"Such jammers disrupt the GPS signal over a fairly large area and the drone loses control. And it cannot be precisely aimed," Ivanov said.
He argued that other possible uses, such as hiding the location of a phone or vehicle, would make less technical sense because other methods can be used to track such objects.
"The only working version is that there was a gathering of people in the area who were worried about a drone attack," Ivanov said.
According to him, the impact on aircraft and television towers may have been an unintended consequence. He suggested that whoever operated the device may not have considered the effect of using it at such power or altitude.
"For me, the disruption of the GPS signal at the airport is a side effect. They simply didn't consider that this could happen," Ivanov said.
He also suggested that a device with such capabilities would likely be subject to export controls, limiting the number of people who could legally possess one. Another possibility, he said, would be that a state-owned device had been modified for civilian use.
The involvement of the national security agency, communications regulator and police reflects the different dimensions of the case. The communications regulator is responsible for matters involving the radio-frequency spectrum and harmful interference, while the police have investigative powers and the national security agency is examining the case within its mandate.
A number of key questions nevertheless remain unanswered. Authorities have not released the manufacturer's name or model, transmission power, exact frequencies, antenna configuration, actual radius of interference or the period during which the device operated.
It is also unclear who placed or operated the equipment and what they intended to achieve. Those details will be crucial for determining whether the case amounts to a radio-frequency violation, a local criminal matter or something with broader national-security implications.
For now, the confirmed fact is that Bulgarian authorities located and neutralized a powerful source of GPS interference in Sofia. The device's reported reach included the airport area, aircraft over the capital and television towers, but there is no public evidence that it was used to deliberately target aviation or critical infrastructure.
The case nevertheless highlights a vulnerability of modern cities: a relatively localized electromagnetic interference source can potentially affect navigation, transport, communications and other technologies that depend on satellite signals. The scale of that risk in Sofia will depend on the technical characteristics of the device and how it was operated.
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