Counter-UAS: a complete guide to drone threat detection and mitigation

The drone threat spectrum

Not all drone threats are the same. Counter-UAS programme design begins with threat classification:

• Category I — commercially available consumer and prosumer drones (DJI, Autel) used for reconnaissance, surveillance, or harassment. Most common threat type; also the most easily detected with standard RF sensors
• Category II — modified commercial platforms with enhanced range, payload, or autonomy. Used for targeted surveillance of specific individuals or facilities; may carry cameras or sensors beyond the standard payload
• Category III — military-grade or purpose-built platforms: fixed-wing ISR drones, loitering munitions, swarming systems. Rare in civilian contexts but relevant for high-value governmental and military facility protection
• Category IV — small, low-observable platforms designed for close-proximity intrusion — minimal acoustic signature, non-standard RF protocols, or autonomous operation without active RF links

Detection technology

RF detection

Most commercial drones communicate with their controller via specific radio frequencies. RF sensors passively monitor these frequencies to detect drone-controller communications and identify the platform type and approximate position. RF detection is the most common detection method but is defeated by autonomous drones operating without active RF links.

Acoustic detection

Arrays of directional microphones detect the acoustic signature of drone propellers. Effective at close range and in quiet environments; less effective in urban acoustic environments or against low-rotor-speed fixed-wing platforms.

Radar

Radar detection covers large volumes of airspace and is unaffected by acoustic environment or RF protocol, but requires significant infrastructure and has difficulty distinguishing small drones from birds at long range. Primarily used for perimeter protection of large facilities or critical infrastructure.

Optical (EO/IR)

Electro-optical and infrared cameras provide visual confirmation and can track a detected drone for identification and engagement decision support. Typically used in combination with RF or radar detection as a sensor-fusion layer.

Defeat options

Drone defeat options divide into kinetic (physical destruction or capture) and non-kinetic (disruption of operation without physical destruction):

• RF jamming — disruption of the drone-controller link causing the drone to return-to-home, hover, or land. Most common non-kinetic option; legal constraints apply in most jurisdictions
• GPS spoofing — feeding false GPS coordinates to cause the drone to navigate to a different location. Technically complex; significant legal restrictions
• GNSS denial — broad denial of satellite navigation signals in a defined area. Legal authority required
• Net guns and capture systems — projectile or drone-launched nets for physical capture. Effective but limited to short range
• Directed energy (laser) — used by military and high-security governmental applications; minimal civilian-legal access

Legal constraints in the Netherlands

Counter-drone operations in the Netherlands are regulated by the Wet luchtvaart, the Telecomwet, and applicable EU aviation regulations. RF jamming requires a waiver from the Agentschap Telecom. Physical defeat of drones is regulated under both aviation law and criminal law. Only law enforcement, military, and specifically authorised private operators may legally use active defeat measures. Mission Support operates within this framework and advises clients on legal authority boundaries before programme design.