Frequent Flyers

The French Ministry of Defence ASSYDUS programme is examining how swarming drones can be used to support air defence suppression missions, specifically to replicate the radar cross section of larger aircraft.

The French Ministry of Defence has lifted the veil on its ASSYDUS (Autonomous System for Decoying Using Uninhabited Aerial Vehicle Swarms) initiative.

It is no secret that the membership of the North Atlantic Treaty Organisation (NATO) is renewing its focus on the Suppression of Enemy Air Defence (SEAD) mission. Russia’s ongoing war in Ukraine, and neither side’s ability to secure air superiority or air supremacy, is concentrating minds. Flying aircraft into contested airspace to fight Integrated Air Defence Systems (IADS) and accompanying Ground-Based Air Defences (GBAD) is arguably one of airpower’s most dangerous missions. Yet controlling the sky depends on neutralising these hostile assets. The less people that must be put in danger when performing this mission, the better.


France’s Ministry of Defence (MOD) unveiled the ASSYDUS project in late November. The initiative is being led by Thales and the University of Bordeaux’s LABRI (Laboratoire Bordelais de Recherche en Informatique/Bordelais Information Research Laboratory) in western France. The MOD says the ASSYDUS project focuses on using swarms of Uninhabited Aerial Vehicles (UAVs). These swarms could be flown in such a way as to provide a Radar Cross Section (RCS) mimicking that of a conventional aircraft. Replicating these platforms has an obvious tactical advantage when inhabited aircraft are attacking IADS/GBAD targets.

Using swarms of UAVs to resemble conventional aircraft approaching a radar from one direction could provide a useful diversion. With the radar fixated on the fake ‘aircraft’ it could then be struck kinetically or electronically from another unexpected direction. The MOD’s literature says the swarms of UAVs could also deploy sensors across a large area. This approach could be used for the mass collection of electronic intelligence on hostile radars. Moreover, individual UAVs maybe difficult to detect by radar on account of their small physical size and hence small RCS.


Thales told Armada in a written statement that LABRI is focusing on the swarming aspect of the initiative with the former working on radar decoying and RCS simulation. The company is also ASSYDUS’ software architect and integrator.

The ASSYDUS concept uses multirotor drones capable of carrying a six-kilogram (13.2-pounds) payload. Thales’ statement said that the payloads included communications, obstacle avoidance systems, radar reflectors and on-board computers. Nonetheless, the company stressed that “the developed solution is not limited to these types of drones … Platforms with a small enough RCS are particularly interesting, because they can be almost undetectable while spaced out.”

The UAV swarm can “mimic various sizes of helicopters, jet and propeller aircraft.” The UAVs will fly significantly slower than these aircraft. Nonetheless, Thales said the swarm can replicate the flight profiles of such platforms, including their velocities, but how these speeds can be mimicked “cannot be disclosed.”

Thales added that work on ASSYDUS is expected to be completed by April 2024. The key aspect of the programme was to demonstrate the ASSYDUS proof of concept. To this end, the architecture has been developed to Technology Readiness Level-4 (TRL-4). European Union definitions denote that TRL-4 means the technology has been validated in the laboratory. The next step of the project “will include both other drones and other payloads possibilities, in order to improve the decoying solution and to collect operational data.” Expect further developments of the ASSYDUS architecture in the coming years.

by Dr. Thomas Withington