Cheap to produce, launched by the thousands and causing great destruction in the Middle East, Iran's "Shahed" drones, one of which killed a French soldier in Iraqi Kurdistan on Thursday, have means to counter attempts to intercept them, BTA reported, citing AFP.
Autonomous navigation
Jamming GPS signals is a widespread practice in the Persian Gulf region in order to disorient enemy armies and drones, but it leads to serious disruptions in maritime navigation and in everyday life. However, many drones still hit their targets.
"By not using GPS, you avoid this jamming", Thomas Whittington, a researcher at the Royal United Forces Institute (RUFI), told AFP.
"Just before or just after takeoff, the drone turns on a GPS receiver to determine its location," he explained.
A gyroscope is then turned on, which measures the speed, direction and position of the device depending on the place from which it took off. This is inertial navigation in standalone mode.
At the moment of hitting the target, the drone can turn on its GPS again or remain in inertial navigation mode, but with the risk of a more inaccurate hit.
Mechanisms to counter signal jamming
In the war in Ukraine, the Russian drones "Geran-2" of the "Shahed" type have "the most advanced jamming suppression system, in other words it suppresses enemy jamming signals while preserving the desired GPS signal", the American think tank "Institute for International Security Studies" said in 2023.
Radio jamming devices were found on the remains of a drone in Cyprus in the early days of the current war in the Middle East, a European defense industry source told AFP.
"It is assembled from commercially available parts, but has many of the capabilities of the US military's GPS equipment," Todd Humphreys, a professor at the University of Texas at Austin, told AFP.
"The "Shahed" drones "are modernized," explains Ukrainian Air Force spokesman Yuriy Ignat. "To counter this, more sophisticated and more numerous means of electronic warfare are needed," he adds.
The materials they are made of
"Radar easily detects large aircraft made of metal because metal is a conductive surface that reflects a lot of energy back to it," notes Thomas Whittington.
Iranian drones, however, are often made of "lightweight materials that absorb radar waves" such as plastic or fiberglass, RUSI explained in a 2023 publication.
The size of the drones and their low-altitude flight allow them to slip through the network of detection systems.
Does Iran use other navigation systems?
Does Iran use the Chinese navigation system "BeiDou" (BeiDou) – a competitor to the GPS system? The issue has observers concerned, with some believing it could increase resistance to jamming.
"Some signal transmissions are harder to jam than others, but they can all be jammed," Dana Howard, president of the "Foundation for Sustainable Navigation and Synchronization", a US non-governmental organization specializing in protecting critical infrastructure from threats related to GPS communications disruption, told AFP.
Other suspicions fall on "Loran", a satellite-free radio navigation system developed during World War II and decommissioned after the advent of GPS. The Iranians announced in 2016 that they would resume using this alternative to the GPS system, but according to a number of experts, there is currently no evidence that it is active.
This type of system also requires a network of large ground-based transmitters, which are more visible and, above all, can be targeted by bombing.
How can we better protect ourselves?
To protect themselves from drones, armies are focusing on another option: shooting them down with guns, missiles, interceptor drones or even lasers, which the Israelis and Americans are most actively developing.
As for the greater effectiveness of jamming, "it all depends on the ability to detect the drone's radio emissions if it is emitting signals", points out Thomas Whittington, having considering the final phase of the flight.
The Ukrainians, for their part, have shown that jamming works.
They claim to have managed to jam, divert or "spoof" (so-called spoofing) the signals of a significant number of Russian drones. Between mid-May and mid-July 2025, Kiev neutralized 4,652 Russian drones thanks to "electronic warfare" means, compared to 6,041 shot down, out of a total of 12,851, according to Ukrainian military data analyzed by AFP. The two types of means - electronic and conventional - are often used in parallel.