APRS

APRS — the Automatic Packet Reporting System — is a real-time, two-way digital network that runs over amateur radio. Every station that hears a packet can relay it, so information moves across a whole region without needing the internet at all.

Most people know it as a way to see where a station is on a map, but position is only one type of packet APRS carries. The same network moves short text messages between stations, weather data from home and portable weather stations, telemetry from sensors, and status updates from fixed objects like repeaters or road closures. Net control can post a bulletin. A weather station can report wind and temperature every few minutes without anyone touching a keyboard. A station out in the field can drop a message to another operator with no cell signal in sight.

Because every packet is heard — and repeated — by anyone listening, APRS also works well for situational awareness during public service events and emergency activations: it's an easy way to see, at a glance, who's where and what conditions look like across the whole coverage area.