Decatur, IL -- A Sonoma County, CA, judge has ruled a speeding case supported by an officer's radar cannot be thrown out because the speeder's GPS system allegedly contradicted the radar speed.

Roger Rude, a retired Sonoma County sheriff's lieutenant, brought the case, fighting a ticket his stepson, Shaun Malone, received for going 62 MPH in a 45 MPH zone. Rude had installed a GPS system in the car to track his stepson's speeds. Rude alleged Malone never was speeding based on the GPS tracker.

Late last month the court ruled against the GPS data, holding that radar data is more reliable.

JB Harper, Radar Systems Engineer for Decatur Electronics, the manufacturer of the radar that clocked Malone, said radar is a time-tested speed assessment tool.

"Decatur radar has been catching speeders for more than 50 years," he said. "Radar reads a speed at the speed of light rather than calculating geographic and time differences between two separate readings as is done in a GPS system."

Officials with the Petaluma Police Department, which issued the ticket, agreed. Petaluma Police Capt. Dave Sears said GPS is a valuable tool but is not as accurate for tracking speed as radar.

Decatur Electronics created the first radar for law enforcement more than 50 years ago. Their expertise in radar is supported by more than 200,000 Decatur radars in use worldwide by police departments and military. The company also partners with law enforcement with its in-car digital video, and speed and message trailers.

yea I don't think GPS readings are that accurate.

GPS units can have a variety of errors associated with them. The ones in cars don't have Receiver Autonomous Integrity Monitoring, which checks for satellite and self errors and warns the user. They don't require calibration or anything. If they're poorly positioned in the car that can affect their readings. If you're in a valley that can affect the reading.

I'd think that a radar unit in this case would probably be more accurate.

Going uphill/downhill, or around the bends will make your GPS reading slower than the actual speed is as well.

All true, but the folks who make their money selling radar units nevertheless must have heaved a small sigh of relief, to see their gadgets vindicated in court. The Taser people will be envious.