Iran's unmanned aircraft prove difficult to intercept

The M142 High Mobility Artillery Rocket Systems, or HIMARS, has been conducting live-fire missions during "Operation Epic Fury" at an undisclosed location, as seen in a photo by US ARMY / AFP, showcasing the military's capabilities in the face of threats from Iranian-designed Shahed drones.

n

These drones have proven to be cheap and deadly, causing significant damage in the Middle East war, and are equipped with anti-jamming and other capabilities that make them difficult to stop, according to experts.

n

Shahed drones are designed to explode on impact and typically connect to GPS to register their location shortly before or after takeoff, then turn off their receivers, as explained by Thomas Withington, a researcher at Britain's Royal United Services Institute (RUSI).

n

They then travel long distances towards their target using gyroscopes that measure their speed, direction, and position, known as an "inertial navigation system", allowing them to avoid GPS jamming, which is prevalent in the Middle East, as noted by Withington.

n

"GPS is going to get jammed by whatever is protecting the target," Withington told AFP, highlighting the limitations of relying on GPS for navigation, and adding that "if you look at a map of GPS jamming at the moment in the Middle East, you see that there's a lot of jamming… By not using the GPS, you avoid that."

n

The drones can then return to GPS just before impact for a more precise strike, or remain offline, with Withington noting that "it's not always necessarily very accurate, but it's as accurate as it needs to be".

n

Russia has been producing Shahed-style drones for use in its war in Ukraine, with the US-based Institute for Science and International Security discovering in 2023 that these drones utilize "state-of-art antenna interference suppression" to remove enemy jamming signals while preserving the desired GPS signal.

n

Anti-jamming mechanisms were also found in the wreckage of an Iranian-made drone that struck Cyprus in the opening days of the Middle East war, according to a European industry source who spoke to AFP.

n

Experts, such as Todd Humphreys, a professor of aerospace engineering at the University of Texas at Austin, have noted that the Shahed drones have been constructed using off-the-shelf parts, but possess many of the capabilities found in US military GPS equipment, making them a formidable opponent.

n

Defending against these drones now requires sophisticated electronic warfare equipment, as stated by Ukrainian air force spokesman Yuriy Ignat, who said "The Shaheds have been upgraded".

n

The Shahed drones are built from "lightweight radar-absorbing materials", such as plastic and fibreglass, as outlined in a 2023 RUSI paper, allowing them to evade detection and slip through aerial defence systems due to their small size and low altitude.

n

Some experts believe that Iran is utilizing multiple positioning systems, making it easier for its drones to dodge jamming, with Serhii Beskrestnov, a technology adviser to the Ukrainian defence ministry, suggesting that Iran is using the BeiDou system, a Chinese rival to the US-developed GPS.

n

The Russia-made version of Shaheds uses both BeiDou and the Russian equivalent, GLONASS, according to Beskrestnov, while others suspect that Iran may be using LORAN, a radio navigation system developed during World War II.

n

LORAN, which does not require satellites, largely fell out of use when GPS emerged, but Iran announced in 2016 that it was reviving the technology, which requires a network of large ground-based transmitters, although experts have not confirmed it is active today.

n

Militaries have primarily defended against Shaheds by shooting them down with cannon fire, missiles, and interceptor drones, with the United States and Israel also developing lasers as a countermeasure.

n

However, jamming can also be effective, as demonstrated by Ukraine, as can "spoofing", which involves hacking into the drone's navigation system to change its destination, providing an alternative method of neutralizing the threat.

n

Ukraine used electronic warfare to neutralize 4,652 attack drones from mid-May to mid-July 2025, a significant number, and not far off the 6,041 drones shot down in the same period, according to AFP analysis of Ukrainian military data.

n

Ukrainian experts emphasize that electronic and conventional defences are often used in tandem against the drones, highlighting the importance of a multi-faceted approach to counter the Shahed threat.