July 28, 2026 – “What is APRS?”

Good evening. This is W1UT and tonight’s training is about “What is APRS?”

This is another interesting ham radio topic that a number of ham operators like to use and experiment with. APRS stands for (Automatic Packet Reporting System) and is used to provide location and other data reporting via ham radio anywhere in the world. Yes, there are cell phone apps that can do much the same thing, but APRS can do more such as transmitting position data from a balloon and was developed back in the 1980s long before smart phones. I personally know little about this topic, but I did some research to present this to all of you listening tonight.

APRS was initially developed by Bob Bruninga (WB4APR) in the 1980s. APRS is a real-time digital communications protocol which transmits small data packets mainly on the 2m band to share GPS coordinates, weather data, text messages and status updates. The system relays on digipeaters that connect to Internet Gateways which allow for global visibility. Here in North America the standard frequency for APRS is 144.39 Mhz and uses the AX.25 protocol at 1200 baud. If you remember what the old phone modems or fax machine audio sounded like on a land line, this is what APRS sounds like. I am told that another application of APRS is its use during emergency events. How this is used is something I have never been involved with. 

In its simplest implementation, APRS is used to transmit real-time data, information and, optionally, reports of the exact location of a person or object via a data signal sent over amateur radio frequencies. This requires a connected GPS receiver for position reporting. APRS is also capable of transmitting a wide variety of data, including weather reports, short text messages, radio direction finding bearings, telemetry data, short e-mail messages (send only) and weather data. Once transmitted, these reports can be combined with a computer and mapping software to show the transmitted data superimposed with great precision upon a map display.

Most amateurs use APRS for real time position reporting, but text messages can also be sent to email addresses using a local internet gateway. APRS software can plot your location on a map based on transmitted GPS coordinates as well as provide means to send text messages, weather data and any other data suitable for 1200 baud packet data. I suspect that APRS is used extensively in the mid-west by amateur radio operators tracking tornadoes as part of SkyWarn. Apparently a number of low-Earth orbiting satellites, including the International Space Station, are capable of relaying APRS data.

APRS seems to be growing in the Salt Lake metropolitan, Utah County and St. George areas. Rural areas in Utah have little to no activity from what I have been able to determine. I live in Wasatch County and there is no activity here. To find out if there is activity in your area talk to other hams at a local ham club and/or do some research on the internet.