GPS: Vehicle Tracking

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apratt@
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Vehicle Tracking Products and Information

For purposes of domestic tranquility - that is, so my wife knows I am still alive when I'm out alone on the motorcycle - I got interested in vehicle tracking. I have investigated and even tried three or four technologies. One of them, a ham radio based system called APRS, is described on another page on this site. (The short answer is I couldn't mount the antenna so it would work reliably on my motorcycle.)

All these tracking systems are based on having a GPS receiver in the vehicle to tell the device where you are, and some kind of radio to send that information out to the web. In some cases the GPS device and radio are in the same device, like in a GPS-enabled cell phone.

Besides APRS, tracking technologies are based on two main radio systems for getting the signal out: cell phones and satellites.

Satellite

One satellite system is Star-Traxx. It's easy to set up: you put their device on your vehicle someplace where it can see the sky, give it power, and that's it. Everything else is done through the web and by the Star-Traxx people. Since it uses satellites to transmit your position back to the company, it works even when you're out of range of any cell-phone tower. But I found out it's not that great in California. See, the radio transmission path has to be clear between the vehicle and the satellite. If there are buildings, hills, or mountains in the way, the system won't work. This company uses two satellites to cover the USA: one over the Atlantic east of Florida and one over the Pacific west of Hawaii. California is right in between, and it's just barely in the "footprint" of the Pacific satellite. In fact, the satellite is only 10 to 15 degrees above the southwest horizon throughout California. Out in the Central Valley or along the coast, this is great. But in town or anyplace hilly, and there's going to be something between you and the satellite. The company recommends a slightly different, higher-profile device for tracking vehicles that will be in California, but I was told by a couple of owners that the reliability in California isn't very good. Also, their basic system reports your position every hour, while the systems based on cell phones can give much more frequent updates. I decided I didn't want to pay their kind of money for the low-reliability tracking.

The Analog Cell Phone System

I've found lots of vendors for the commercial tracker described at http://www.earthtrak.com/et_cellular.htm ... From that company, it's only $300 to buy, and $7 per month for their lowest plan. Trouble is, it uses the analog cell phone system, and that system is scheduled to die about March 1, 2008. (See the Wikipedia entry for AMPS.) Even factoring that in, this could still be a winner.

The Digital Cell Phone System

The digital cell phone systems I investigated work using Motorola phones on the Nextel system, including the Motrola i415 phone available for under $100 and prepaid service through the Boost service.

The systems I've found that work on the i415 phone via Nextel service are:

Loopt, a "hip" commercial service startup (new in 2007). You can see a person's position from the web, or from another Loopt phone. But you can't see any history, only the most recent position report. And at the moment you can't see how old the position report you're viewing is.

Mologogo is free - that is, no additional charge on top of the phone and the phone's Internet-enabling data service. The Java app on your phone shows maps and would show the locations of friends if I had any. You can give the client a URL and it will send your position reports to that URL in addition to the Mologogo server; this lets you feed the findu database using inputpos.cgi. The mologogo maps can show where you are and where you've been, and you can include a map on a web page by specifying that page's URL as an authorized outer frame on the mologogo site.

AccuTracking costs money. The phone client is more primitive, showing no maps. You can't use another cell phone to see a map of a person's location. The server is high-feature, with geofence management and e-mail alerts for lots of events.

I have not found these systems to be very reliable. You can't just turn on the phone at the start of a motorcycle ride and forget about it. I have to watch the phone and "burp" it occasionally when it gets stuck. It could be a firmware problem related to moving in and out of coverage areas. There are happy customers who report leaving their trackers in place for a week or more; maybe their stalkees stay inside coverage all the time.

 

 


This page was last edited April 26, 2008.