Examples
Acoustic drone and bird detector: hearing direction with eight microphones
A weatherproof field node with a 3D microphone array estimates the bearing of drones and birds; two or more nodes combine their bearings into a position.
- 3 creditsdesign cost
- 64BOM lines
≈ € 1 000
per extra node
2 nodes
for a position
3
majors resolved
The idea
Detect drones and birds around a site without cameras: acoustic only, processed on the node, with no raw audio stored. The project grew into a network of nodes that share time through GNSS.
What Daedalus produced
Array design
8 MEMS microphones on a 3D layout for better elevation accuracy
Acquisition
Teensy firmware sampling all channels on one clock
Signal processing
SRP-PHAT direction finding and a harmonic detector on a Raspberry Pi
Multi-node fusion
Bearings from several nodes combined into a position on a server
Enclosures
Printed weatherproof pods and a mast mount
Privacy notes
What the node records and why no audio leaves it
What the red team found
Bearing accuracy depends on air temperature
The temperature sensor sat inside the pod and read high in sun. Fixed: shaded external probe.
Outdoor microphones can pick up speech
Fixed: processing on the node only, no storage of raw audio, documented in the goal.
GNSS timing unverified
Fixed: module with PPS output chosen and the timing budget checked.
Build it yourself
Use the node design as a template for other acoustic sensing: bat detectors, machine monitoring or noise mapping. The array geometry and the processing parameters are part of the design, so the agent can adapt them.
Related:
Use case: Sensor networks →
Guide: Red-team findings →