What Is APRS? Automatic Packet Reporting System and Ham Licensing

APRS (Automatic Packet Reporting System) is a digital communications protocol used in amateur radio for real-time exchange of position information, weather data, text messages, and other short data bursts. Created by Bob Bruninga (WB4APR), APRS has become one of the most widely deployed digital amateur radio systems in the world, with thousands of active nodes and users.

How APRS Works

APRS operates primarily on 144.390 MHz in North America (a national simplex calling frequency used by APRS stations). Stations with GPS receivers broadcast their position data in APRS format. A network of digipeaters (digital repeaters) rebroadcasts these packets to extend range. Internet gateways (iGates) relay the packets to the APRS-IS (internet system), where they appear on tracking websites like aprs.fi in real time.

What Can You Track and Report with APRS?

• Vehicle and mobile station positions (excellent for convoy tracking)
• Weather station data (temperature, wind speed, rainfall)
• High-altitude balloon positions during flight
• Search and rescue team positions
• Storm spotter locations during SKYWARN activations
• Short text messages between stations

License Requirements for APRS

Because APRS uses 144.390 MHz, which is in the 2-meter amateur band, a Technician class license (or higher) is required to transmit on APRS. Anyone can receive and view APRS data — the tracking websites are public — but transmitting APRS packets requires an amateur radio license.

APRS Hardware

APRS can be implemented with dedicated APRS radios (like the Kenwood TM-D710), handheld radios with external TNCs (Terminal Node Controllers), or software-defined setups using a Raspberry Pi, a radio, and free software like Direwolf. The barrier to entry for APRS is relatively low, making it a popular first digital mode for new Technician licensees.