Detect the drones that radio-based systems cannot.

Passive infrared tracking for drones without a radio link.

Limitations of current counter-drone systems

Most counter-drone systems work by detecting the radio link between a drone and its operator. They cannot see the aircraft now dominating the battlefield: drones flying pre-programmed routes, drones that have lost their link, drones controlled by fibre-optic cable. Radar covers part of the gap but is itself limited: as an active emitter it is detectable, jammable and targetable in turn, and small drones barely register.

Our approach

The Tensec system is built specifically for the unmanned aircraft (UAS) that radio-frequency detection cannot see. It tracks by thermal signature rather than by signal, capturing the drones that fly without a transmitting link.

A drone without a radio link still emits heat, and a thermal camera detects it whether the drone transmits or not. Targets are triangulated from two positions to produce a three-dimensional track. The system itself emits no signal, leaving nothing for an adversary to detect, jam, or use as a guidance reference.

Telling a drone from a bird

An eagle and a small quadcopter can present almost the same picture to a sensor: similar size, similar height, similar warmth. The system separates them on how they move as much as on how they look, reading flight behaviour alongside thermal signature and shape, and it classifies each track itself rather than asking an operator to confirm one alarm after another. Aircraft, drones and birds are sorted apart automatically. A counter-drone system that cannot make that distinction is unusable in practice: it raises the alarm on every bird that crosses the site.

An eagle, acquired and held. At this range the bird is a few pixels of warmth against a uniform sky. The system finds it, follows it, and files it as a bird rather than raising it as a drone.

Down to the smallest targets

The system acquires and tracks a DJI Mavic 3, a small commercial quadcopter with no military thermal signature to speak of. Anything larger, faster or hotter is easier. How far out any given target is held depends on its thermal signature, on the optics fitted and on the conditions on the day, so we would rather demonstrate it against your own target set than quote a figure that would not hold.

A DJI Mavic 3 held on the thermal channel against broken cloud. The drone is transmitting nothing the system uses. The track runs on heat and motion alone.

The tracker is not limited to targets in the air. The same head holds anything that moves and gives off heat at ground level too. Here a wild boar crosses open ground at night.

Complementary, not a replacement

The Tensec system is designed as a complementary capability, not as a complete counter-drone solution. Effective C-UAS defence requires multiple sensor types, each covering what the others miss. We provide the passive, emission-free layer: holding the target track when radio-frequency detection is blind and when radar has been suppressed by jamming or tactical restriction. The system operates independently and integrates with the radar and RF systems already in use.

Built on proven technology

This is not a new product. It applies Tensec’s Video Tracking System, already proven in fast-aircraft tracking on military ranges, to the counter-drone mission. For the underlying technology, see the Video Tracking System page.

Configured to your airspace

Each installation is configured for the specific airspace requiring protection. Installation and on-site commissioning are always included.