Last March, an alarming situation prompted the General Directorate of Civil Aviation (DGAC) to alert the National Frequency Agency (ANFR) of GPS disturbances affecting SAMU helicopters near Lille.
With hindsight, the ANFR can talk more calmly about this story of jamming dating back to the end of winter 2023. On March 15 and 16, the helicopters of SAMU 59 (Nord) and 62 (Pas-de-Calais) reported position losses. The satellite positioning system (GNSS) which notably uses the GPS and Galileo constellations is altered, even though it is vital for their mission. The DGAC calls on the ANFR, whose agents have identified not one but two jammers potentially responsible for the disturbances. A hunt then begins to locate them.
A GPS jammer discovered in a professional vehicle, which tried to hide its geolocation
On March 22, the initial hypothesis of a single GPS jamming was quickly ruled out by investigators from the Boulogne-sur-Mer branch, who therefore quickly identified two potential sources, one fixed and the other mobile. The need to locate these transmitters becomes imperative, because critical SAMU operations must be secure.
Add to this that GNSS losses can also hamper aircraft takeoffs from Merville aerodrome, west of Lille. It is particularly around this area that the two ANFR agents, equipped with specialized receivers, will carry out their research. Unfortunately, the stationary jammer remains inactive that day, but signals lead the second investigator to a crucial discovery in Calais.
The investigator’s insight leads him to the location of a GPS jammer in Calais, about a hundred kilometers from the initial area. It turns out to be installed in the vehicle of a professional on intervention, which neutralizes its geolocation, which is illegal in passing. The ANFR reminds that the possession and use of a GPS jammer are offenses punishable by a fine of 30,000 euros and 6 months in prison. The agency requests the immediate intervention of the national police to seize the equipment, which makes it possible to neutralize this first jammer in less than a few hours. But the matter is not over yet.
New jammers discovered the next day, this time at a private home
The jamming resumed the next day, which forced the ANFR investigators to continue their mission. The technicians again equipped themselves with their receivers and directional antennas, and they managed to reach a house near the Merville airport.
With the help of the gendarmerie, they managed to get their hands on a first multi-band jammer, purchased on the Internet and discovered in this house located in the town of Estaires. But yet, the agents always notice a disruptive broadcast. And that’s normal, because they end up discovering a second jammer, hidden in the garden shed.
Summoned to the gendarmerie, the owner had to give up his jammers, and that was the end of the disturbances affecting the SAMU helicopters and the surrounding planes. A mission once again smoothly carried out by the units of the National Frequency Agency.
Source : ANFR
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