Basically the radar detector is a device that allows you to know whether the vehicle in which the radar detector installed is being tracked by radio waves from a radar gun being pointed at, which is the device most police forces use to track the speed of the vehicle. How a radar gun works is a radio signal sent from the police radar gun against your vehicle, and signal bouncing and back to the radar gun at a certain speed.
If your car is not moving at all, the radio signal back basically the same speed. If you move them back at a faster rate, and this can be measured to measure exactly how fast you are traveling. Simple physics, but it is quite accurate in most cases. If you are looking for lidar technology companies then check lidarinsurance.
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So what will be an important factor when choosing a radar detector? Well first of all not all built the same. Some are more accurate, some are more portable, and some were without cable for quick removal.
There are other types of radar detectors signal the most basic can not even read, and it is a laser signal. Yes, the new weapons used by the police actually use something called LIDAR, which stands for Light Detection And Ranging, to measure the speed of the car.
This weapon can not be detected by standard radar detector, so you may need to obtain what is called a "jammer" to fully protect yourself. It is illegal in most countries, so if you're caught using one ready for a hefty fine.
Another thing to consider is that even the standard radar detector will not smell out radar radar gun the police if they are not on active status.
New LIDAR guns are "instant on" device, so you can slide down the highway and suddenly get a hit on your radar detector, just a few hundred feet of a policeman standing with a gun in his hand. So really, even if you have a radar detector is best to keep your speed down and not rely on it too heavily. This can save one or two tickets, but if you ignore the legal speed up sooner or later you may have to pay.