How radar that take photos to cars works?

Question

i ask about how the radar for cars that detect its speed by take pictures to them please any one know tell me at

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thanxxxxxxxxxxxxx

Answer 1

The speed of any vehicle passing the unit is measured using a radar on the front of the camera in a wide beam across your half of the road it measures the time for the pulse to travel to the car and back this then calculates the speed of the vehicle in mille seconds. The camera then takes two photos of your car - hence the two flashes. It takes two images so that the speed shown on the resulting photographs can be double checked by calculating the distance the car has moved between pictures.

Answer 2

Photo radar is unlike traditional hand-held radar in two important respects, all of which increase its accuracy and make it almost impossible for violators to detect the beam before their violation has been registered. These differences are its low output, which at maximum strength is only twenty-five milliwatts, and its cross-the-road beam, rather than the traditional hand-held down-the-road beam.

The accuracy of the unit is greatly enhanced by these two differences, the low output and the beam direction. The photo-radar unit beam cuts across the road, and can thus detect the vehicle exceeding the set speed limit at a closer range to the patrol vehicle. Furthermore, with a maximum output of only twenty-five milliwatts, the farthest an object's velocity has been measured is across 5 lanes of highway. These two differences also result in making the radar beam almost impossible for radar detectors to identify until they have already been recorded by the unit.

Photo radar systems usually operate on the K-band at 24.15GHz. This is important because this is designated by the FCC as one of only two bandwidths permanently assigned for use by police radar.

As a car passes through the beam emitted by the radar antenna, the radar antenna makes a series of measurements of the vehicle's speed. Upon identification of a speeder from these measurements a signal is sent to the central processing unit, which in turn directs the high speed camera to take a photograph of the violator.