Glossary

C-UAS (Counter-UAS)

Equipment and procedures for detecting, tracking, identifying and neutralising unwanted drones.

UAV / UAS

The drone itself (unmanned aerial vehicle), or the drone together with its controller and supporting systems (unmanned aircraft system).

Detect–Track–Identify–Mitigate (DTIM)

The four steps of counter-drone operations.

RF detection

Passive sensing and analysis of the radio link between a drone and its pilot.

Direction finding (AoA)

Determining the angle of arrival of a radio signal using multiple antennas.

Time difference of arrival (TDOA)

A geolocation method that measures the time differences with which the same signal reaches several sensors.

Radar cross section (RCS)

How "visible" an object is to radar. A small drone's RCS is comparable to a bird's.

AESA

Active electronically scanned array – a radar antenna that steers its beam electronically, without moving parts.

Micro-Doppler

Characteristic modulations that spinning rotors add to a radar echo; used to tell drones from birds.

EO/IR

Electro-optical (day) and infrared (thermal) cameras.

PTZ

Pan-tilt-zoom camera.

Slew-to-cue

Automatically turning a camera onto a target reported by another sensor (radar, RF).

Sensor fusion

Merging data from several sensors into a single tracked target.

C2 (command and control)

The software interface where the operator sees the operating picture and where decisions are made.

PSIM

Physical Security Information Management – software that brings security systems onto one interface.

VMS

Video Management System – CCTV management software.

GNSS

Global navigation satellite systems (GPS, Galileo, GLONASS, BeiDou).

Jamming

Emitting radio noise in a drone's control, video or positioning bands so it can no longer receive them.

Jamming-to-signal ratio (J/S)

The strength of the jamming signal relative to the wanted signal at the drone's receiver; it determines whether jamming is effective.

Spoofing

Transmitting false signals – typically false GNSS signals – to deceive a drone.

Protocol takeover (cyber takeover)

Taking control of a drone through its own communication protocol.

Failsafe

A drone's pre-set behaviour on link loss: hover, land or return.

Return to Home (RTH)

A failsafe mode in which the drone flies back to its take-off point using GNSS.

FPV (First Person View)

A drone flown through goggles showing its camera feed; often custom-built and very fast.

Remote ID

Identification and position data broadcast by a drone.

Geofencing

Manufacturer software restriction that prevents a drone from entering certain areas.

Probability of detection (Pd)

The likelihood that the system detects a drone that is present, under given conditions.

False alarm rate (FAR)

How often the system alerts when no drone is present.

Whitelist

A list of authorised, known drones for which the system does not alert.