New Scientistmagazine reports that researchers at the University of Tennessee and Batelle Institute have applied for patents on asystem that detects the speed of a passing vehicle based on its exhaust note.

The system uses microphones tocapture the sound of a passing car, and then filters out all but the sound made by the engine. By measuring the dopplershift of the engine sound as it moves past the speed trap, the system can calculate the vehicle's speed.

While the sound detector is unobtrusive and completely passive (therefore undetectable by a conventional radar/laserdetector), identifying speeders will require something a little less stealthy, like a traffic camera. Of course, otherearly detection systems are possible, like the subtle warning in the accompanying picture.

Hmmm. Sounds likebetter muffler technology is in order.

 

Even still, everything in motion has a doppler shift. Even if the exhaust noise was completely eliminated, the roar from the tires would be enough to detect and calculate.

Next time we go to the Dragon, we should invite these scientists for a ride... you never know. They may deem the technology flawed and "just a bit too much" after a change of perspective @ 9K

 

so they would have to have base readings for every make and model car right? engine speed at 6K engine speed at 7K, etc. and which gear will it pick up? 6K RPM in 3rd gear is not speeding, 6K in 6th gear is!

 

No, they're not looking at engine RPM's, like Mulder said, they're looking for the doppler shift. That train whistle thing they taught us in school.

 

LOL, the train whistle. I think everyone since the dawn of time has seen that video eplaining the doppler effect...

 

MyBride shifted my Doppler one time. Those scientists could've heard me a mile away!


btw, New Scientist is a cool mag.

 

What tha ?!?!?! :

....and we are obsessed