Aprs
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Amateur Posistion Reporting System (APRS)
What is APRS?
- APRS is a protocol.
- APRS is a way of sharing data pertinent to an area of interest between stations - usually graphically.
These areas of interest can be as small as a building to the size of a continent. Information shared can include anything from a position to weather data, to dynamic boundaries, to email, to telemetry, to custom data types and more. You can even play chess by APRS. There are so many things that can be done with APRS, it's rather difficult to describe. A generalized description often used is similar to:
A tactical, real time situational awareness system.
For more information and detail on the many aspects of APRS, visit any of the many available web sites for some ideas. A few of the more popular sites include:
- APRS on Wikipedia
- http://aprs.org Bob's (WB4APR) site The one who started it all
- http://www.aprs.net Pete's site Creator of many of the Java APRS tools
- The APRS Wiki
Using google search and a little effort, you'll find many viewpoints, opinions, tools and ideas. Much more than I can cover here!
Even if you were to read every APRS site on the Internet, you'd likely not have a full perspective of all the way that it can or is being used for. By design, APRS is intended to meet YOUR needs.
The closest we have to an Official APRS "Bible" would be the APRS Spec v 1.0.1 (Aug 31, 2000) hosted at TAPR. "The Spec", created by the APRS Working Group, was an attempt to define the on the air protocols.
The spec was valid at the time of publication. At that time it was THE definitive guide of how to 'do' APRS on the air. As an active and dynamic technology, APRS changes and develops with time. You can find clues to these changes on Bob's web site - but it may take a bit of digging. Sadly, the spec itself has not been kept up to date with current practices - but as as core guide, remains very useful.
Using APRS in the Casper Area
The national APRS frequency of 144.390 (FM AFSK) is used throughout Wyoming. If you've a TNC or can connect the audio output of your radio to your PC's sound card - you're ready to get involved. Even if you don't have a radio - just a PC and an internet connection, you can join in.
The Casper Mnt digipeater KD7AGA-6 and the Copper Mnt digipeater KD7AGA-5 are both sponsored by CDK Net. A small club in the Casper area. Your support of APRS is very much appreciated! Both of these digipeaters help to provide excellent APRS coverage for Natrona county and a large part of Wyoming. 2 W7VNJ club members operate I-gates - each on a different ISP. This provides reliable and redundant I-gate service for the area.
I've set up a java APRS client on my own web server at the house. You can see local APRS activity by clicking that link. You'll have to allow the applet to run by accepting the signature from Analysis & Management Enterprises Corp. This applet only listens to the APRS traffic as heard at my QTH on 144.390. There is no internet feed. Please allow enough time for the applet, the maps and images to load - there's a lot there and will take some time, especially over a dial-up connection.
If you know the callsign of a station, you can see their current position by visiting http://map.findu.com/<callsign-ssid>. For example, to see my -6 station, visit http://map.findu.com/ka7o-6. Findu is a fantastic resource for APRS data.
If you've any questions - feel free to ask on the discussion board, at a CARC meeting or on the RM-APRS email reflector hosted at Yahoogroups.com.
The I-gate at KA7O-15 is also an internet server that provides the worldwide APRS Internet System (APRS-IS) data feed at aprsdcsp.ka7o.net. That server will provide APRS-IS data feed for most any APRS client software. Just add aprsdcsp.ka7o.net to your server list and have fun! You can see it's current status here.
The following image is a 'snapshot' showing a few weather stations, my motorcycle, a 'sailboat' and some of the trails recorded during that day.
APRS Clients
The staggering array of software and devices is simply a testament to the ingenuity of the Amateur Community. Please, feel free to add to this!
Xastir
X Amateur Station Tracking and Information Reporting
Here's a "step by step" how to that'll guide you in getting Xastir up and running on a Fedora system. Just follow along and enjoy!
NOTE: At one time, the xastir.org site was unavailable Here's a local copy of our own Xastir on Fedora Page for getting Xastir up and running.
APRS Server
APRSD
APRSD is "the origional" server/gateway that made up the APRS-IS. Still available, it is the only fully Open Source server I know of. Most servers have moved to JavAPRS. But, though it's freely available to hams, Pete keeps the code to himself. See the APRSD page for hints, guide and how to - especially on Fedora.
Thanks to the Fedora Amateur Radio Group, aprsd is now available in the Fedora repositories! Install with a simple sudo yum install aprsd <enter> - configure and go!
(TM)
APRS is a registered trademark of APRS Software and Bob Bruninga, WB4APR.
