Of course, not all radar detectors are created equally. With the constant evolution of radar and laser technology, it’s important to know which features will keep you properly alerted to oncoming hazards. In this guide you’ll learn not only how radar and laser detectors work, but also which features you should look for when purchasing one.

The difference between radar and laser

Radar guns are used to measure the speed of your vehicle. They do this by emitting radio waves. When the trigger is pulled, the gun is essentially bouncing radar waves off your vehicle and back to the gun for measurement. Due to a phenomenon known as the Doppler Shift, the change in distance between your car and the gun allows the gun to calculate your speed.

Because radar guns require radar waves to track your speed, radar detectors in turn detect commonly used radar frequencies. Since the radar waves that are emitted from a radar gun travel a farther distance than is necessary for the radar gun to properly track your speed, the radar detector can often provide an effective warning of a radar gun’s presence.

What exactly is a radar detector?

While radar guns use radar waves to track speed, a laser gun (or Lidar gun) uses invisible infrared light. The laser gun emits rapid bursts of light that bounce off your car and back to the gun. By calculating the distance change of your vehicle between laser bursts, your speed can be properly measured.

While radar guns are more common, the use of laser guns is fast increasing. This is because laser guns emit a very accurate, narrow beam compared to radar guns. This pinpoint beam can make detecting laser guns more difficult, but not impossible.

Important features

Now that you know a little bit more about how radar and laser detectors work, let’s take a look at some common features you’ll need to be aware of.

Frequency band protection
Currently, radar guns in the United States operate on three bands: X, K and Ka (some European countries use the Ku band).

X band (10.525GHz) was the original frequency and is currently only found on older radar guns. It is being phased out due to improved accuracy and range of the two newer bands.
K band (24.0150GHz) replaced X band as the band of choice back in the 1970s. The majority of radar guns today operate on this band.
Ka band (33.4-36.0GHz) was introduced in the late 1980s. The use of this band is increasing.

Due to the fact that it is possible to encounter any one of the X, K or Ka bands as you travel throughout the United States, it is highly suggested that the radar detector you choose is capable of detecting all three bands.

Moreover, it should be noted that triple-band detectors have been known to come in a few different varieties: triband, wideband and superwide band. The distinction between the three comes in the amount of Ka coverage that can be detected. Given that superwide band radar detectors provide protection across the entire Ka frequency, these radar detectors are recommended. In this way, you have the capability to be alerted to any radar gun that you might encounter.

Laser detection
Because lasers guns are very accurate and do not emit a constant signal, they are much harder to detect than radar guns. However, a detector equipped for laser detection is more than capable of alerting you to a laser gun that is pointed at your car. It should be noted, however, that the warning provided will generally provide a much smaller window of time to slow down before your speed registers on the laser gun.

POP™ mode protection
POP mode is a relatively new feature on K and Ka band radar guns. As opposed to the constant radar transmission of older models, these guns have the ability to dispense an extremely brief burst of radio waves. This brief burst makes detection of these guns a bit more difficult, and is in fact impossible if your radar detector doesn’t have POP mode protection. The use of POP-enabled radar guns has increased in recent years, therefore a radar detector that provides POP protection is probably a good idea.

360° detection
Modern radar guns have the capability to target your vehicle from the front, rear or side. To provide full protection, it is critical that your detector can detect radar and laser signals from every direction. To do this, you’ll need a detector with 360° detection.

Safety Warning System
You’ll want a radar detector outfitted with a Safety Warning System (SWS) if you’d like to be alerted to traffic and weather hazards. With this feature, your detector is capable of picking up radar transmissions that can warn you of such road hazards as approaching emergency vehicles, construction sites, a train approaching a crossing and weather-related hazards. Knowing about these road hazards beforehand can save you time by allowing you to find a detour around the problem area.

False alert protection
Radar waves are emitted by more than just radar guns and SWS-related hazards. Automatic door openers, burglar alarms and motion-sensing technology in some newer car models can all set off your radar detector. Obviously, these false alarms are unwanted.

Designed for use while you are in residential or city areas (where more false alarms occur), a City Mode can significantly reduce false alarms from your detector. While in this mode, the detector will filter out weak radar waves and either provide a reduced warning or no warning at all.

Higher end models also incorporate sophisticated filters that further reduce the occurrence of false signals.

VG-2 protection and spectre
VG-2 protection, sometimes called “Stealth,” is a feature on some radar detectors that functions in a way that “hides” the detector from being detected by radar guns.

Display Methods

Now that you know a little bit more about how radar and laser detectors work, let’s take a look at some common features you’ll need to be aware of.There are various methods that radar detectors use to display their radar warnings. And while each is effective, it can broadly be said that the higher end models offer more information in an easier manner.

Low-end models typically will warn you only of a radar wave’s presence, along with the strength of the signal. Midrange models often add the ability to distinguish between types of bands, and can generally inform you which types are within range (X, K, Ka or Laser). High-end models usually go one step further and offer up a dot-matrix display that clearly informs you of the specific signals that are targeting you. They may also add the benefit of voice alerts, which allow you to be informed of oncoming threats without having to look at the detector and let you keep your eyes on the road.

Know the law

In most cases within the United States, radar detectors are legal*. However, they may be prohibited or limited in some areas and in certain types of vehicles, such as large trucks.

For the most part, as long as you are outside of Virginia, Washington D.C., or any other zones that may prohibit the use of these devices and are not operating a commercial vehicle (truck greater than 10,000 lbs.), you will most likely be free to use your radar/laser detector within the United States.

One related law worth mentioning pertains to radar detectors used in California and Minnesota. State laws prohibit the mounting of any device on a vehicle’s windshield or windows. So if you are planning on using your radar detector in California and Minnesota, just make sure you don’t mount it on your windshield.

Note: It is ultimately the responsibility of you, the radar detector owner, to know the laws in your area regarding the legality of the use of radar and laser detectors.

Summary

Now that you’re more acquainted with the technology and features of radar detectors, it’s time to start shopping. Keep in mind that warnings against all radar bands (X, K, Ka and laser) and 360° detection are essential for full protection. Beyond this, look for the features that suit you. How many false alerts are you willing to put up with? Would you like the added benefit of a Safety Warning System? What kind of display method is right for you? Once these questions are answered, you’ll know exactly what features you require in your radar detector.

And now that you know what you’re looking for, why not start shopping?


*RadioShack does not sell laser/radar detectors where prohibited by law; use may be regulated by state or local laws.

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