APRS Messages? What are they realy?

I keep on reading the APRS messages, but dont get why are they so important to be included in the outernet downlink.
Whay are their importance, and why should we all receive them?

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I had to learn this for myself too :slight_smile:
Firstly the amount of bandwidth that the simple text takes on the downlink from the satellite would be negligible, and they seem to “squeeze” in between the rest of the content.

Why are they important? (This is my view only and not the view of the Outernet team)

APRS is a simple and ready made “Back Channel” where one can transmit an APRS message and it will be delivered to the Outernet receivers in minutes.

At a time when information may need to be sent to a remote location (without internet) during some emergency etc. quickly you can see the use there.

Because the APRS message can be sent from a remote location via another satellite or HF radio and “inserted” into the APRS backbone to get to the Outenet transmitter, it could be used to request particular information from somewhere without internet access, that may be wanted at some remote location.

The input to the APRS network is self-regulating due to the restricted access ( by Licensed Radio Amateurs) there is little risk of anything “unacceptable” turning up in the text

Currently the idea is to create some traffic so that the interfaces can be tested, so most of it will be trivial at the moment ( e.g. I have a beacon running in HF once an hour which may or may not make it to the APRS backbone and thus onto the Outernet)

I hope that helps :slight_smile:
Neil M0KNC

I am a fairly new ham and have not spent a lot of time with APRS. How do I set my Outernet message box to show my APRS messages?


APRS packet messages are sent out from a ham radio station. There are dozens of ways this can be done. These packets are uni-directional, broadcast like a beacon and don’t require acknowledgement. The APRS packet is received by another ham radio station and forwarded through a gateway to “the cloud” over the Internet. By the way, you can see the data on the cloud here: APRS on Google Maps

Outernet sifts through the cloud data and looks for any messages that contain OUTNET anywhere in the message and send them on through their satellites. The comment section of the message is the easiest to modify. Here’s the APRS Protocol V1.0 so you can see what is in the packets.

For example. The International Space Station can fly over. You can send a beacon on VHF / UHF. It will pick up your location information and the comment field saying OUTNET. It will pass that data on to the APRS "cloud’. In turn OUTNET sifts-out your packet and broadcasts it via the OUTERNET satellites. You or your friends can see your location, telemetry, etc. on Outernet.

If this interests you and you don’t have a ham license, there are many clubs around the US that will help you get your license in a weekend or two. Learning morse code is no longer necessary. The costs of the license may be around $15 and some instructional materials. I can’t speak for ham radio in other countries since the regulations vary widely.

Incidentally, an APRS message does not have to go over the air by ham radio to be sent into the “cloud” if you have an Android smart phone. However, you still need to be authenticated to use this service with your callsign. APRSdroid

–Konrad, WA4OSH