Microphones on poles¶

Radar was built for aircraft, and a small drone flying low between trees and buildings gives it almost nothing to see. Sound is cheaper: a microphone on a pole hears the rotors, three poles place them, and the same poles hear everything else in the street. Five students built that network for a hackathon and won, before anyone had written down what a pole may keep.

Five students from the machine-learning club at Rzeszow University of Technology won the Detect & Defend hackathon in March 2026 with a network of microphones that places a small drone where radar has a blind spot. Armadni zpravodaj described it on 29 April 2026, with the list of what it does not yet do.

Three microphones make a map¶

Each node has a microphone and runs, on the node, a model trained on the acoustic signature of drones. When a node hears one it sends an alert over a Meshtastic mesh, encrypted with AES-256 and needing no mobile network. Three nodes in the vicinity of the target are enough to place it, and if one node fails another takes its role.

The radio part and the trained models were finished; the integration and field tests were not, and the team named power consumption of the nodes as the main brake.

A small commercial drone flying low has a tiny radar cross-section, moves slowly and merges with terrain, trees and buildings. A passive acoustic sensor still hears a drone where radar hits clutter.

Missing: a public benchmark, a test against radar, a published range, false-positive data. Wind, rain and background noise degrade it. Its security stands and falls with the encryption keys and the node settings, and a badly set-up mesh could tell an adversary more than it detects.

After the win, public institutions and defence firms got in touch, and the city of Rzeszow offered to support testing in real conditions. No contract was public.

A town listening to itself¶

It is an extremely cheap first detection layer that anyone can afford: a municipality, an industrial estate, a military base. A network of microphones on poles across a town listens to the town. Attack D6 is what a node keeps of what it hears before the model decides it is a drone. The list does not say.

Last reviewed: 2026-09-25.