(Automatic Packet Reporting System)
According to the developer, Bob Bruninga, WB4APR, "APRS is not a vehicle tracking system", although for most of us that is the most used feature of the program. On his website (http://aprs.org/), Bruninga states, "It is a two-way tactical real-time digital communications system between all assets in a network sharing information about everything going on in the local area. On ham radio, this means if something is happening now, or there is information that could be valuable to you, then it should show up on your APRS radio in your mobile. APRS also supports global callsign-to-callsign messaging, bulletins, objects email and Voice because every local area is seen by the Internet System (APRS-IS)! APRS should enable local and global amateur radio operator contact at anytime-anywhere and using any device."
In reality, how much a person can do with the system depends on the equipment he has. If one has a fully equipped APRS radio, there are many options of what can be done with APRS. If not, one's choices are limited. Thus, most of the user's I know use it solely for vehicle tracking. One of the least expensive devices used for this is the TinyTrak GPS position encoder which, when connected to a serial GPS and a radio, will transmit its location at an adjustable rate. I use the TinyTrak3 Plus, although the new improved TinyTrak4 with more features is now available from Byonics (http://www.byonics.com).
My "TinyTrak in a Box" helps keep needed cables and connectors in order and all I need to do is grab the box, the GPS and a 30-watt amplifier made by Realistic when I'm ready to leave. A 5/8-wave mag-mount antenna is already in the truck.
The box is one that once held different equipment, so I don't know where you would get one like it. Three of these were given to me. Beneath the foam I have placed aluminum foil. The black box does heat up in the sun, and this seems to help keep the inside components somewhat cooler.
The radio in the box is a Realistic HTX-202 with the battery pack removed. Cables for power, the GPS input and the antenna coax exit the box which remains closed during use. Software provided with the unit is used to set the beacon's interval.
Anderson Power Poles make the connections to the power. I use them on all of my radio equipment.
Two other ham friends use the TinyTrak3 beacon, and I have followed their paths via the Internet to New Mexico and Texas, and as far east at Dayton, Ohio, during the Dayton Hamvention. I have been tracked from Colorado to as far as Quartzsite, AZ. For the money, the little units do a very good job.
For those without APRS equipment, hams may be tracked at www.FindU.com. Several of my non-ham friends keep track of me when I am on the road.
Here is an example of the track my unit made on a trip back from Quartzsite, AZ in 2011. Each red dot on the route represents a beacon that was successfully transmitted to an IGATE station and placed on the Internet. There were a few areas where there was not coverage, but overall it was a very good track by the equipment shown above.
It used to be that I used a PK-232MBX TNC to run APRS from my home. More recently, however, I set up APRS using a sound card instead of the TNC. I use the Yaesu FT-897D transceiver on 2-meter FM, an MFJ-1279M sound card interface, and a Dell Latitude D610 laptop computer. For the software, I am using AGWPE and UI-View. Thanks to these pages from KC2RLM on the Internet, the transition was almost painless:
In addition to using the sound card for home use, it can also be used for portable use in our small travel trailer. Also, by connecting to an IGate, I have been able to send messages for many hundreds of miles to other hams using APRS.