APRS is short for Automated Packet Reporting System. It was developed in the late 80’s by Bob Bruninga WB4APR. It is a digital mode commonly found on VHF and on some HF bands. APRS is a decentralized packet system where packets can be rebroadcast multiple times. It can broadcast real-time information including positions, speed, weather data, and free text. You can send messages to local, regional operators or to operators in far off places.

In the US, you can find APRS on 144.39 FM. If you want to try APRS from the ISS, the frequency is 145.825 – Just be aware of the Doppler shift. Want more info? Try this page: HOW TO WORK THE ISS WITH APRS

What is an APRS packet?

What can I do with APRS?

What is a Digipeater?

What is an IGate?

How can I check if my signal was received?
There is a fantastic website that shows all relevant

Feel like you got a handle on APRS and want to try something harder? Try this: HOW TO WORK THE ISS WITH APRS and RASPBERRY PI & APRS