T TYRFING ARMS / Defence technology — Oslo, Norway

Project BAT

Passive acoustic drone detection for military and critical infrastructure protection.

Tyrfing Arms is developing BAT, a compact hemispherical microphone array for real-time UAV detection and direction-finding at forward positions, checkpoints, and critical infrastructure sites.

The problem

Acoustic drone detection is an established, NATO-proven technology — but existing systems are designed for fixed installations only. There is no commercially available solution for vehicle-mounted, mobile acoustic C-UAS.

This gap is confirmed by Norway's current C-UAS procurement framework, which covers fixed sites exclusively. The same detection gap exists across critical infrastructure, border crossings, and public venues.

The system

BAT uses an array of six MEMS microphones in a hemispherical configuration to detect and locate drones in real time by analysing their rotor acoustic signatures. The system is fully passive — no RF emissions, no licensing required.

Sensors
6 × MEMS microphones
Geometry
Hemispherical array
Emission
Fully passive
Detection range
~100 m (Class I UAV)

Status

Prototype development

Field testing planned with a target drone as acoustic reference.

About

Tyrfing Arms AS is a Norwegian defence technology startup based in Oslo. The company was founded by a researcher with a PhD in physics and electronics, and prior experience from drone systems research, materials science, artificial intelligence, and modern software development.

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