Wednesday, Apr 13, 2005 at 10:16
Hi Trev, To be able to operate APRS within ham radio one needs a license and for a run down on that look here It's not a difficult exam but ones does need a basic understanding of electronic and radio theory along with radio regulations
The APRS network consists of the individual stations reporting positions by radio or direct connection to the internet, repeaters and gateways that channel positions and messages to and from internet servers. The internet servers are also connected thus we have a network
As a simple example if I was driving around Geelong where I live I'd have my system set up to
beacon my position every 2 minutes. My
beacon is heard by a repeater which repeats my
beacon. An internet gateway hears my
beacon from the repeater and fires it into a web server which distributes my position to all the other internet servers. Depending on my location my
beacon may have to go through 2 or 3 repeaters before being heard by a gateway.
In remote locations or locations not so remote that are not covered by repeaters
HF radio must be used, there are a few HF gateways around Oz and any number worldwide. There are also a few amateur satellites that can be used for APRS and the international space station has a repeater on it but when using low orbit sats one is limited to the short window when the sat is passing over. There are numerous Sat predictions programs available that will tell you when to expect the Sats overhead.
There are other uses for APRS, some users have weather stations that automatically report weather conditions.
For a brief rundown on APRS in Oz look here
For me along with all other hams it's a worldwide communciations hobby but it does have practical uses.
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