Open flight tracking exists because tens of thousands of volunteers point a small antenna at the sky and share what they hear. AeroScope stands on that distributed network. Here is how it works — and how collaborative, multi-receiver tracking can push it further.
An ADS-B broadcast is line-of-sight and fades with distance, so no single receiver sees far. But overlap thousands of them and their individual horizons stitch into continuous coverage. Volunteers run a cheap software-defined radio, decode 1090 MHz locally, and feed positions to aggregator networks that republish the combined stream.
Individual receivers — often a Raspberry Pi and an antenna — each cover a local bubble of sky and forward what they decode.
adsb.fi, adsb.lol, airplanes.live, OpenSky and others combine many feeders into open regional and global feeds.
A satellite-ADS-B layer reaches oceans and remote regions where ground feeders are sparse, completing the map.
AeroScope consumes these networks and fuses them into a single de-duplicated picture. Want to add to the mesh yourself? Our receiver setup guide walks through it.
Older aircraft transmit Mode S without a GPS position. When four or more receivers hear the same message, the tiny differences in arrival time can be solved into a position — multilateration (MLAT). It is a clean example of why density matters: the more overlapping receivers, the more aircraft become visible and the better positions can be cross-checked.