Counter-drone glossary.

Acoustic detection

Detecting drones by the sound of their motors and propellers using microphone arrays. Short range, and affected by background noise.

Aerodrome traffic zone (ATZ)

Protected airspace around an aerodrome, usually a cylinder of 2 or 2.5 nautical miles radius and 2,000 feet high. It forms part of an airport’s Flight Restriction Zone.

Air Navigation Order (ANO)

ALSO: AIR NAVIGATION ORDER 2016

The main UK law setting rules for aircraft, including drones, alongside the UK regulation on unmanned aircraft operations. The Civil Aviation Authority oversees it.

BVLOS

ALSO: BEYOND VISUAL LINE OF SIGHT

Flying a drone further away than the pilot can see it unaided. In the UK this needs authorisation from the Civil Aviation Authority.

C-UAS

ALSO: COUNTER-UNCREWED AIRCRAFT SYSTEMS, COUNTER-DRONE

Everything used to protect a site or event from drones: detection sensors, command and control software, procedures and, for authorised bodies only, equipment that acts on a drone.

Classification

Deciding what a detected object is, for example a drone, a bird or an aircraft, and sometimes which make and model of drone.

Command and control (C2)

Software that brings sensors together into one picture, helps operators decide what to do and records what happened. Wardglass is Uavity’s counter-drone command and control platform.

Common operating picture

A single live view of everything in the airspace that every member of a team sees, rather than a separate screen for each sensor.

Drone

ALSO: UAV, UAS, UNCREWED AIRCRAFT

An aircraft flown without a pilot on board, either by remote control or along a pre-programmed route.

Effector

Equipment that acts on a drone rather than just detecting it, for example a jammer, a spoofer, a net or a drone that captures other drones. In the UK only the police and other authorised bodies may use effectors.

EO/IR

ALSO: ELECTRO-OPTICAL AND INFRARED

Cameras that see in visible light (electro-optical) and heat (infrared), used to confirm a detection by day or night and to capture imagery as evidence.

Flight Restriction Zone (FRZ)

Airspace around a protected aerodrome where drones of any size may not fly without permission. Prisons in England and Wales have similar restricted zones reaching roughly 400 metres from each site.

Flyer ID

Proof from the Civil Aviation Authority that a person has passed the basic drone theory test. Since 1 January 2026, anyone flying a drone of 100 grams or more needs one.

Geofencing

Software in some drones that stops them flying into mapped restricted areas. It is set by the manufacturer and can be unlocked or disabled, so it is not a protection a site can rely on.

Identification

Working out who a drone belongs to and whether its flight is approved, for example from Remote ID or a submitted flight plan.

Jamming

Transmitting radio noise to block the signals a drone relies on. In the UK it is an offence under the Wireless Telegraphy Act 2006 for anyone not authorised.

Mitigation

Acting on a drone to stop or move it, as opposed to detecting it. Also used more broadly for any step that reduces the risk a drone poses, such as moving people indoors.

NPSA

ALSO: NATIONAL PROTECTIVE SECURITY AUTHORITY

The UK government authority for protective security advice. It publishes guidance for site owners on drone threats and counter-drone measures.

Open category

The UK category for lower-risk drone flights, covering most leisure and many commercial flights, with limits such as keeping the drone in sight and below 120 metres. Riskier flights fall into the specific or certified categories.

Operator ID

A registration number from the Civil Aviation Authority for the person or organisation responsible for a drone. It must be labelled on the drone and is included in its Remote ID broadcast.

Radar

A sensor that transmits radio waves and detects their reflections, finding drones whether or not they use radio themselves. It needs a clear line of sight and has to tell drones apart from birds.

Remote ID

ALSO: RID

A broadcast from a drone in flight carrying its Operator ID, serial number, position, height and course, and the pilot’s position. Required on UK1, UK2 and UK3 class drones since 1 January 2026, and on most other drones of 100 grams or more with a camera from 1 January 2028.

RF detection

ALSO: RADIO FREQUENCY DETECTION

Passively listening for the radio signals between a drone and its controller. It can find drones and, with some systems, their pilots, but may miss drones flying without a live radio link.

SAPIENT

An open interface standard, developed in the UK and published by BSI, that lets sensors and counter-drone systems from different makers share data.

Sensor fusion

Combining detections from different sensors into one track per object, so several sensors seeing the same drone produce one picture rather than many alerts.

Spoofing

Sending false signals, such as fake satellite navigation, to mislead or take control of a drone. Like jamming, it is reserved for authorised bodies.

Track

The record of one object’s movement over time, built from one or more detections. A track carries a position, a heading and a history.

VLOS

ALSO: VISUAL LINE OF SIGHT

Keeping a drone close enough that the pilot can see it unaided at all times. Required for flights in the open category.

Wireless Telegraphy Act 2006

The UK law governing use of the radio spectrum. It makes deliberate interference with radio signals, including jamming drones, an offence.