RF detection is today the most deployed technology in civilian drone security. It is mature, cost-effective and EU-compliant — but its performance varies a lot with context. Here is the technical reality, in plain language.
Physical principle
A passive RF detector continuously listens to specific bands: 2.4 GHz, 5.1 GHz, 5.8 GHz Wi-Fi, Bluetooth Legacy, Bluetooth Long Range. When it captures a drone-characteristic frame (Remote ID, or proprietary signature from a consumer model), it triggers a detection event.
It emits no signal — hence no transmit authorisation needed — and does not require visual contact with the drone.
Cooperative vs non-cooperative detection
Cooperative: the drone broadcasts its own identity (Remote ID, French signalement). This has been the default since 2024 for every EU drone from class C1 upwards. Extremely reliable detection, possible pilot identification, near-zero false positive rate.
Non-cooperative: a drone is identified by its radio signature (e.g. Wi-Fi frames from certain consumer models or known proprietary links). More delicate, requires an up-to-date signature database.
Why range varies
A "5 km in free field" figure is a reference under ideal conditions: no physical obstacle, low ambient RF noise, direct propagation. In dense urban or building-rich environments, useful range can drop by a factor of 2 to 4.
Drone altitude matters too: a drone at 100 m is generally "seen" farther than one at 10 m because propagation is less obstructed.
Expected performance levels
Rather than focusing on raw range, measure the useful metrics: detection rate on common consumer drones (target > 95% in normal conditions), alert latency (< 2 s), false-positive rate (target < 1% per day), model recognition rate (target > 80% of consumer drones).
DECTYR RX-5 currently recognises more than 380 drone models thanks to a regularly enriched database.
Honest limits
A home-made drone flying autonomously on GPS, without an active radio link, will not be detected by passive RF. For those cases (rare in civilian security, more common in defence contexts), radar or EO/IR must complement the picture. For the great majority of civilian sites, passive RF detection covers 90% of real threats.
FAQ
Does RF detection catch DJI drones?
Yes. DJI dominates the civilian market, and its drones (Mini, Air, Mavic, Phantom, Matrice…) are identified through Remote ID and/or proprietary signatures.
What is the impact of nearby Wi-Fi?
Serious detectors filter standard Wi-Fi frames and only trigger on drone signatures. Neighbouring Wi-Fi does not significantly raise false positives.
Can an RF sensor be installed in a city?
Yes — it is a standard use case. Useful range is reduced but remains enough to cover a site or a city block.