APRS - For whom is this useful?

Robert · 2019-12-02T10:55:03.488Z

Hi,

Sorry! This is a somewhat provocative question from a non-radio amateur.

This is the first time I’ve heard of APRS. I understand that APRS is useful for those who send these signals. But is this messages also useful for strangers? For example, there are always messages about the International Space Station. Can I, as a non-radio amateur, also do something with it?

I have nothing against sending APRS news here. But I’m interested.

Thank you
Robert

Mark_Phillips · 2019-12-03T20:50:09.426Z

You sure can do something with it. Look carefully at the messages. You’ll see that they contain lat/lon co-ordinates either in plain text or base64 scrambled (not encrypted). The base64 allows the content of the message to be significantly shortened this consuming less time on the air when sent at 1200bd (the speed of the APRS RF network).

Take a look at a thread I started a few years back; “Are you a ham? Stand up and be counted”. Are you a ham? Stand up and be counted - #145 by BruceFerrell We’ve noted a significant number of hams that are participating in this project and to this day we still get checkins from new hams via that thread.

So as a user community hams make up quite a large number of participants and so APRS is useful to us. And that’s the point; its a demonstration of a service to a particular membership.

Robert · 2019-12-04T07:10:24.019Z

Thank you for those clues. I will take a closer look at the messages and pay attention to the coordinates.

So can I use it to determine the coordinates of the International Space Station?

Mark_Phillips · 2019-12-04T15:48:15.581Z

I don’t think you can get the position of the ISS as lat/long only applies to the ground. These beacons are forwarded by the receiving station via RF. So you could extrapolate the general region of the world that the ISS is over at the time of the reception report.

However, APRS is much more than a positioning system. Again, look at the messages. You can parse them by eye most of the time and pull out messages. Search the past messages from me (NI2O-5) and you’ll see tests etc. That text could be anything. It could be telemetry data about battery health at the local radio tower or weather data or general 'hello world" stuff. Whatever you can fit into that space.

Take a look at http://aprs.fi where you’ll find a decent WWW GUI that’ll allow you access to all that APRS data as well as AIS (APRS for ships) data too.

Robert · 2019-12-05T06:18:17.152Z

Hello Mark,

Did you send me a message via APRS? (It’s not raining here either.)

Can I also send messages via APRS even though I don’t have a HAM license?

Thank you

Mark_Phillips · 2019-12-05T12:42:16.210Z

@Robert In general you cannot send messages via APRS if you do not have a ham licence. However, some jurisdictions do allow something called 3rd party messaging which would allow you to send a message under the supervision of a controlling ham operator.

And yes I did send you a message which for me in the USA is technically illegal as it was a message intended for a non ham and so is therefore a “broadcast” (see FCC’s Part 97 rules). I’m glad to hear it’s not raining where you are either

So you see how these messages are useful now?

sam_uk · 2019-12-05T13:01:21.918Z

A while ago I had this idea to generate search results. Search Wikipedia via APRS?

It never got built though.

Robert · 2019-12-08T09:30:54.277Z

This is a very interesting application. But it would only be useful for HAMs, wouldn’t it?
How many HAMS are known in Africa?

Mark_Phillips · 2019-12-08T17:36:42.849Z

“How many hams are known in Africa?” About 200000.

But this is not a “service for hams” but rather this is a demonstration. It just so happens that as hams we can do this very easily and so the effort involved from @Syed side to create the demo is almost none.