Radar detectors are small devices that help identify the presence of radars, such as those used by police to locate cars driving over the speed limit. Certain types of radar detectors also identify the presence of laser speed guns, which may be useful for those looking to avoid speed traps that traditional radar detectors may miss. In order to understand how exactly a radar detector works, it’s helpful to understand the manner in which basic radars operate.
How Does Radar Work?
Radars are frequently used to identify distance and speed, such as how far away an object is or how fast it is moving. A radar device emits a radio wave, which moves at the speed of light, and bounces back to the radar device when it encounters an object in its path. Based on how long it takes for the radio wave to hit the designated object (for example, a tree at an undetermined distance) and how long it takes the wave to bounce back, the radar device can figure out the distance between the device and the tree.
When a radar is used to detect speed (for example, the rate at which a car is moving), the radio wave frequency of the returned signal is altered because the car is moving. If the car is moving toward the radar device, the return signal has a shorter distance to travel and the radio wave frequency increases. The radar device can then use the change in frequency to determine the speed at which the car is moving. In a laser speed gun, waves of light are used in place of radio waves.
A simple radar detector identifies radar devices based on the radio waves it emits. Essentially, radar detectors simply act as radio receivers, picking up specific frequencies used by radar devices, specifically radar guns used by police to identify and catch speeding cars. Because radar devices used by police cast a wide net of radio waves but only track one specific target, radar detectors in moving cars often pick up on radar radio waves before the car comes within close enough range of the police car to be tracked.
Other, more advanced radar detectors not only detect police radar, but can essentially throw off the reading a police radar detector receives. In these types of radar detectors, a radio transmitter emits a scrambled signal (called a jamming signal) which takes the original detected signal and adds additional radio signals. When the scrambled signal reaches the radar, the police have trouble getting an accurate speed reading. A similar system exists for laser speed guns (called lidar) wherein the laser detector emits a scramble beam of light.
How far away can a radar gun get your speed?
What about distance? How far away can a police officer get your speed?
It really depends on the radar gun as well as terrain, but in ideal conditions, radar guns can get your speed a mile away or more. Larger vehicles like big semis present an even larger reflection and so they can be clocked farther away. Smaller vehicles like cars or even motorcycles present smaller reflections so they’ll need to be closer. As a general rule, if the radar gun has a clear line of sight view of the target, they’ll be able to get its speed.
The things that will prevent a radar gun from being able to lock in a speed are things like hills, curves, buildings, or trees. Radar guns do need direct line of sight to work (as opposed to radar detectors that can see around bends thanks to reflections) so anything in the way of the radar gun’s signal, including traffic and other vehicles, can prevent the radar gun from acquiring a target at a distance.
How do radar detectors help you avoid tickets?
Radar detectors are THE tool to help you avoid speeding tickets from radar guns.
The general idea with radar detectors it that they’re designed to alert you to the presence of police radar up ahead, before you’re close enough to where the radar gun can acquire your speed. Radar detectors can detect police radar much farther away than radar guns can clock traffic up ahead, so the odds are in your favor here. Radar detectors are designed to give you plenty of advanced warning so that you can double-check your speed accordingly and avoid a speeding ticket.
There’s a lot of great radar detectors out there and there’s also a lot of lousy ones. If you’d like help picking out a radar detector.
Types of Radar Detectors
Of course, there are different kinds of radar that a radar detector must be sensitive to. An x-band radar has a low-frequency and a high output, making it relatively easy to detect from 2 to 4 miles away. However, devices other than police radars generate x-band signals, including garage door openers and microwave towers. K-band radar is most commonly used by police, and has a small wavelength. A k-band cop radar can conduct an accurate reading from .5 to 2 miles away, making it difficult for radar detectors to pick up on the wavelength beforehand because of their small wavelength.
How to avoid speeding tickets?
How do we avoid getting tickets? Here’s several basic, but key suggestions:
By understanding a little bit about how radar guns work, you’ll have a better idea of how to protect yourself from them.
How Radar Detectors Work
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Rachid Haddadi
