ISS APRS Tracking

Hi All,

I have been doing a lot of reading lately and focusing on things that interest me the most in the hobby. Sometimes I will take a few days to decide what I want to be doing next. I usually want to do something that I haven’t done before

When I first heard about hams and hobbyists tuning in to the up link that is on the ISS to decode SSTV , and other modes as well as analog from them, I thought, well that is the most interesting thing i have heard in a while! After thinking about how great that would be to receive, I wondered when they would do that again now that I am studying what equipment they have onboard. Checking the schedules on NASA’s info pages, I discovered that it may be a while for me to even attempt intercepting comms from them. It wasn’t even on their calendar. That thwarted my attempts to go forward with the interest as they aren’t going to be doing any of those things (any time soon). I figured out what they do during downtime (no events planned.) It turns out that they pass locations and become a repeater for the APRS networks on the ground and also respond to hello transmissions from the ground that are using the uplink on the ISS radios.

I googled APRS, and downloaded the APRS client for Windows 10. I loaded up and became a peer, but i wasnt going to try TX until I get my ham license. I read what the protocal is and how it behaves on the ground. Also, the ISS becomes a repeater for the area that it passes.


So since all I could do is wait for it to pass and just intercept APRS messages . I discovered this tool called “Dire Wolf” and configured it to listen to my virtual audio cable installed for comms between SDRuno, and a program to pipe the audio to. After setup, I let the ISS pass over my part of the country and fire up the Dire Wolf program and monitored 145.825MHz, just to see until the events start happening again on the ISS. Below is what i found at first.

Author: WA4333SWL

Founder of

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