What is APRS?

What is APRS?

APRS stands for Automatic Packet Reporting System. It is a digital communications protocol used by amateur (ham) radio operators to share real-time information across a local or global network. APRS was created by Bob Bruninga, WB4APR (SK), in the late 1980s and has since grown into one of the most widely-used digital modes in amateur radio.

What Can APRS Do?

APRS supports a wide variety of data types, making it a versatile tool for the ham radio community:

• Position Reporting — Share your location in real time, useful for tracking mobile stations, hikers, and events
• Weather Reporting — Automated weather stations transmit temperature, wind speed, rainfall, barometric pressure, and more
• Messaging — Send and receive short text messages between stations, including group messaging
• Telemetry — Transmit sensor readings such as battery voltage, solar panel output, or environmental data
• Status Updates — Broadcast free-form text about your station's current activity

How Does It Work?

At a high level, APRS combines three key components:

1. Radio — VHF/UHF transceivers (typically on 144.390 MHz in North America) carry the data over the air
2. Packet Encoding — Information is encoded using the AX.25 protocol and modulated as audio tones (typically 1200 baud AFSK)
3. Network Infrastructure — Digipeaters relay packets over wider areas, and Internet Gateways (IGates) bridge the RF network to the global APRS-IS internet backbone

When you transmit an APRS packet, nearby digipeaters repeat it to extend its range. If an IGate hears the packet, it forwards it to APRS-IS, making it visible to anyone connected to the internet — including dashboards like this one.

Why Use APRS?

APRS is particularly valuable for:

• Emergency communications — Position tracking and messaging when cell networks are down
• Public service events — Real-time tracking of participants in marathons, parades, and other events
• Outdoor activities — Hikers, cyclists, and sailors use APRS for safety and situational awareness
• Weather monitoring — A distributed network of weather stations contributing data in real time
• Community building — Weekly nets like #APRSThursday bring operators together globally

Whether you're a new ham exploring digital modes or an experienced operator building infrastructure, APRS offers a rich ecosystem of tools and applications.