Also known as: APRS
APRS (Automatic Packet Reporting System) is an amateur-radio data network for real-time tactical information — position, weather, telemetry, and messaging. It is carried as AX.25 packet frames using AFSK, most commonly on 144.390 MHz in North America.1
Overview
Stations beacon their position (often from GPS), and digipeaters relay packets so local activity propagates across a region; internet gateways (igates) bridge RF to the global APRS-IS network. The result is a live map of amateur stations, weather sensors, and mobile trackers.
Technical characteristics
| Property | Value |
|---|---|
| Link layer | AX.25 UI frames |
| Modulation | 1200 bps AFSK (Bell 202 tones) |
| Integrity | FCS / CRC-16 |
| Content | Position, weather, telemetry, messages |
History
Created by Bob Bruninga (WB4APR) in the 1980s–90s; it remains one of amateur radio’s most active data modes.1
Deployment
Amateur radio worldwide via beacons, digipeaters, igates, and the APRS-IS network.
Decoding it with GopherTrunk
GopherTrunk demodulates the AFSK, recovers AX.25 frames, and decodes APRS payloads. See the APRS / AX.25 decoder page.
Sources
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Automatic Packet Reporting System — Wikipedia, for the APRS data network, its AX.25/AFSK link layer, payload types, and origins. ↩ ↩2