How Can I Locate a Vehicle Outdoors?

Published: July 11, 2012

What is the complete communication operation of a radio frequency identification solution using active tags, in the context of a real-time vehicle-detection system?

—Name withheld

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I’m unsure what you mean by “complete communication operation.” Every real-time location system (RTLS) operates according to its own proprietary means, but generally, a tag simply emits a signal at a specific interval. A user can set the tag to beacon more or less frequently, depending on how often the location needs to be updated, but beaconing more often reduces battery life.

When the tag emits a signal, reader antennas set up in a distribution yard or other area receive that signal. Different RTLS solutions employ different means to pinpoint a tagged object’s location. One common way is to triangulate on the signal. Software can calculate the location based on the amount of time that it took for the signal to reach each tag.

Another way to ascertain a vehicle’s location in an outdoor application is to link an active tag to a GPS device. The GPS unit would determine the car’s location, and this information would be transmitted via the active RFID solution to a back-end system that would then plot the vehicle on a map.

I hope I have answered your question.

—Mark Roberti, Founder and Editor, RFID Journal