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2009.07.01

Real-Time Google Earth GPS Tracking

In a recent trip I incorrectly assumed that real-time tracking of Google Earth's pre-cached maps with a GPS receiver would be sufficient help for navigating around the highways in Los Angeles. I therefore experimented with the way Google Earth's sparsely-documented real time tracking works, and wrote a small program to interface Google Earth with a GPS receiver. Fortunately, after seeing a colleague drive with a car-GPS device on the dashboard I came to my senses, and got a real Garmin Nuvi car-GPS device.

Although some Google Earth interfacing programs seem to be available at the dark corners of the web, I found it hard to locate them, and, with no source code available, difficult to trust them. They also seemed unwieldy, having many more features than what I required. My logkml program does a single thing, is available in open source form, works on Windows and Mac OS X, and should also work on other flavors of Unix. You can download from here its source code, Windows executable and Mac OS X executable.

The logkml is a console-based program that reads a standard NMEA data stream, which most GPSs can output, and every time it obtains some coordinates it will write them into a specified file, typically named Realtime GPS.kml, in Google Earth KML format. Google Earth will then periodically read this file to update the position it shows. This used to be an advanced feature of Google Earth, but version 5.0 provides it for free. After you start on Google Earth real-time GPS tracking (through the Tools - GPS - Realtime - Start sequence) a new folder titled Realtime GPS will appear in the Places folder. Its properties contain a link file name, which is the one Google Earth will use to update its position.

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Creative Commons License Last modified: Wednesday, July 1, 2009 4:42 pm
Unless otherwise expressly stated, all original material on this page created by Diomidis Spinellis is licensed under a Creative Commons Attribution-Share Alike 3.0 Greece License.