Radar detector

An early radar detector

A radar detector is an electronic device used by motorists to determine if their speed is being monitored by a radar unit. To do so, police bounce a radio wave off of a moving vehicle with a radar gun that determines the vehicle's speed by the Doppler-effect-moderated change in the wave's frequency. Most of today's radar detectors detect signals across a variety of wavelength bands – usually X, K and K_a (as well as K_u, in Europe, also recently approved for use in the U.S).

These devices should not be confused with ones that use GPS technology and a database to warn a driver who is approaching a speed camera location, as is done in the FoxyTag collaborative project.

Newer speed detection devices use pulsed laser light, commonly referred to as LIDAR, rather than radio waves. Modern radar detectors have been modified to alert to the infrared light emitted by such LIDAR guns. LIDAR detection, however, is not nearly as effective as radar detection because the output beam is very focused. While radar's radio waves can expand to 85 feet across at 1000 feet from their source, LIDAR's light beam expands to only about 6 feet. Also, a police officer targeting a car will most likely aim for the center mass or headlight of the vehicle and, because radar detectors are mounted on the windshield away from the beam's aim, they may not alert at all. Lastly, with such a focused beam, an officer using a LIDAR gun can target a single car in close proximity to others at ranges of up to 3000 feet.

While many companies advertise that their radar detectors can 'scramble' or 'absorb' radar and LIDAR (such as Rocky Mountain Radar), many or all of their products do not affect radar and laser signals in any way. If such products do transmit any type of radar scrambling pulses, they are highly illegal. Actively transmitting on an FCC licensed frequency without a license is a violation of FCC regulations and a felony. LIDAR jammers are legal in most states and are regulated, much like police LIDAR guns, by the FDA as Class I laser devices.

Despite the advent of LIDAR speed detection, radar remains more prevalent because of its lower price relative to LIDAR equipment and the amount of radar equipment already in service. Popularity of LIDAR speed detection is on the rise, though, as costs decline, ease of operability approaches radar, and existing radar equipment reaches its end-of-service life and is rotated out of service.

Popular radar detector brands include Beltronics, Cobra, Escort, K40, Valentine One, and Whistler.

Legality

In some countries and areas, such as those listed below, using or possessing a radar detector is illegal and may result in fines, seizure of the device, or both. These prohibitions generally are introduced under the premise that a driver who uses a radar detector will pose a greater risk of accident than a driver who does not. However, some research has found that the opposite is true. The 2001 Mori report suggests that radar detector users posed a 28% less risk of accident.

• Australia: All states besides Western Australia. They are illegal to sell, purchase or possess in SA, NSW, ACT & Vic. Radar Detectors are illegal to use in NT, Queensland & Tas.
• Belgium: In July 2006 a provisional seisure of a vehicle worth over 75.000 EUR itself was ordered by the courts, destruction of the radar detector itself and the driver's license was suspended for 3 months.
• Canada (Illegal:Newfoundland & Labrador, Nova Scotia, Prince Edward Island,New Brunswick, Quebec, Ontario, Manitoba, the Yukon Territory, the Northwest Territories Legal: Alberta, British Columbia, Saskatchewan): Regardless of whether they are used or not, police there may confiscate radar detectors, operational or not, and impose substantial fines.
• Egypt
• Estonia
• Finland
• France
• Germany 75€ fine , 4 Points, destruction of the radar detector
• Greece
• Ireland (Republic of)
• Netherlands 250€ fine and seizure of the device (since 2004)
• Norway
• Poland
• Portugal
• Romania - legal since 2006 (although radar jammers still illegal)
• Spain
• Sweden
• Switzerland, destruction of the radar detector
• Taiwan
• Turkey
• United Kingdom, although not legal to own, but was technically illegal to use under a 1949 wireless act until 1998, due to legal loophole causing them to be legalised suddenly.
• United States law varies from state to state, but detectors are generally legal in private vehicles under the Communications Act of 1934 and illegal in commercial vehicles by DOT regulation (49 CFR 392.71). Exceptions:
  • Illegal in all vehicles: Virginia, Washington D.C., U.S. military bases
  • Illegal in commercial vehicles under state law: Illinois, New York (specifically, commercial vehicles over 10,000 lb. and all vehicles over 18,000 lb.)
  • Indirectly illegal: Minnesota and California (illegal to hang anything from the windshield with suction cups; however both dashboard and visor mounting is allowed.) [1]
  • Repealed: Connecticut (repealed in 1998)

RDDs - Radar Detector Detectors

Main article: Radar detector detector

Because RADAR detectors are built around a superheterodyne receiver, which has a local oscillator that radiates slightly, it is possible to build a radar detector-detector which detects such emissions (usually the frequency of the radar type being detected, plus about 10 MHz). The VG-2 Interceptor was the first device developed for this purpose, but has since been eclipsed by the Spectre III. This form of electronic warfare cuts both ways - since detector-detectors use a similar superheterodyne receiver, many early "stealth" radar detectors were equipped with a radar detector-detector-detector circuit, which shuts down the main radar receiver when the detector-detector's signal is sensed, thus preventing detection by such equipment. This technique borrows from ELINT surveillance countermeasures. In the early 1990s, BEL-Tronics, Inc. of Ontario, Canada (where radar detector use is prohibited) found that merely the local oscillator frequency of the detector could be modified out of the range of the VG-2 Interceptor. This resulted in a wave of detector manufacturers changing their local oscillator frequency. Today, practically every radar detector on the market is immune to the VG-2 Interceptor. To date, the only radar detector that has been proven to be IMMUNE to all RDDs is the [Beltronics STi Driver].

See also

• Federal Communications Commission
• Radar
• Road safety

External links

• Radar Busters Product Tests

• Detector de radar para Portugal

• RadarDetector.net: An online forum where the discussion of radar detectors and other police countermeasures occurs.

• Guys Of Lidar: An independent testing group of both Radar Detectors and Laser Jammers