Radar detector: Wikis


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An early radar detector

A radar detector is a passive electronic device used by motorists to determine if their speed is being monitored by law enforcement agencies via a radar unit, thereby potentially avoiding prosecution for speeding. Only doppler radar-based devices can be detected — other speed measuring devices including those using ANPR, piezo sensors and VASCAR technology cannot be detected, while LIDAR devices require a different type of sensor. Most of today's radar detectors detect signals across a variety of wavelength bands — usually X, K and Ka (as well as Ku, in Europe.)



One of the technologies that law enforcement agencies can use to measure the speed of a moving vehicle uses doppler radar to beam a radio wave at the vehicle, and then infer the vehicle's speed by measuring the Doppler effect-moderated change in the reflected wave's frequency. Radar guns can be hand-held, vehicle mounted or mounted on a fixed object, such as a traffic signal.

Radar detectors use a superheterodyne receiver to detect these electromagnetic emissions from the radar gun, and raise an alarm to notify the motorist when a transmission is detected. False alarms can occur however due to the large number of devices, such as automatic door openers (such as the ones at supermarkets), that operate in the same part of the electromagnetic spectrum as radar guns.

In recent years some radar detectors have added GPS technology. This allows users to manually store the locations where police frequently monitor traffic, with the detector sounding an alarm when approaching that location in the future (this is accomplished by pushing a button and doesn't require coordinates to be entered). These detectors also allow users to manually store the coordinates of sites of frequent false alarms, which the GPS enabled detector will then ignore. Some GPS enabled detectors can download the GPS coordinates of speed monitoring cameras and redlight cameras from the internet, which are contained in the Trinity database. A traveler from out of state, passing through Arizona for example, would receive an alarm when approaching the location of a speed monitoring camera.

Counter technology

Radar guns and detectors have evolved alternately over time to counter each other's technology in a form of civilian electronic "warfare". For example, as new frequencies have been introduced, radar detectors have initially been "blind" to them until their technology too has been updated. Similarly, the length of time and strength of the transmissions have been lowered to reduce the chance of detection, which in turn has resulted in more sensitive receivers and more sophisticated software counter technology. Lastly, radar detectors may combine other technologies, such as GPS-based technology with a point of interest database of known speed trapping locations, into a single device to improve their chances of success.


Radar Detector Detectors

The superheterodyne receiver in radar detectors has a local oscillator that radiates slightly, so 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. [1] 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 the local oscillator frequency of the detector could be altered to be out of the range of the VG-2 Interceptor. This resulted in detector manufacturers responding by changing their local oscillator frequency. Today, practically every radar detector on the market is immune to the VG-2 Interceptor.

Radar Scrambling

Although some companies advertise that their radar detectors can passively 'scramble' or 'absorb' radar (such as Rocky Mountain Radar), many or all of their products do not affect radar and laser equipment due to the low power intake from the device versus the high power that bounces off a vehicle.[2]

It is illegal in many countries to sell or possess any products that actively transmit radar signals intended to jam radar equipment.[3] Actively transmitting on an FCC licensed frequency without a license is a violation of FCC regulations and a felony in the USA.

Passport x50 Radar/Laser detector.

LIDAR Detection

Newer speed detection devices use pulsed laser light, commonly referred to as LIDAR, rather than radio waves. Radar detectors, which detect radio transmissions, are therefore unable to detect the infrared light emitted by LIDAR guns so a different type of device called a LIDAR detector is required. 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 (26 m) across at 1,000 feet (300 m) from their source, LIDAR's light beam diffuses to only about 6 feet (1.8 m). 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 3,000 feet (910 m).

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.


Using or possessing a radar detector or jammer is illegal in certain countries, and it 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 the 2001 Mori report suggests that radar detector users posed a 28% less risk of accident. The table below provides information about laws regarding radar detectors in particular nations.

Country Legality Comment Radar Bands
Australia Illegal in all states besides Western Australia They are illegal to use in a moving vehicle (as stated by the traffic laws in) SA[4], NSW, ACT and Victoria as well as NT, Queensland and Tasmania[5]. Heavy fines apply, ranging from $200 – $1200 AUD, up to 9 demerit points, and confiscation of the Radar Detector. However, importing a unit is permitted under Australian customs regulations.
Belgium In July 2006, a provisional seizure 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.[6]
Brazil Illegal in all states.
Bulgaria Illegal Radar jammers are illegal.
Canada *Illegal:Newfoundland & Labrador, Nova Scotia, Prince Edward Island,New Brunswick, Quebec, Ontario, Manitoba, the Yukon Territory, the Northwest Territories[7]: Regardless of whether they are used or not, police there may confiscate radar detectors, operational or not, and impose substantial fines in provinces where radar detectors are illegal.[8]
Czech Republic Detectors legal, jammers illegal. Fine up to CZK 200.000 (€ 7750), penalty points. Ka
Estonia Illegal to use or have in a motor vehicle. Fine up to 18000 EEK (€ 1150) as well as confiscation of the device.
France *Illegal Regardless of whether they are used or not, police there may confiscate radar detectors, operational or not, and impose substantial fines.
Finland Illegal to use or have in a motor vehicle on a public road. The fine depends on income. The detector will be confiscated. POP Ka
Germany Legal to own, illegal to use in a moving vehicle 75€ fine , 4 Points, destruction of the radar detector. [9]
Greece Illegal 2000€ fine , 30 day driver's license suspension, 60 days car registration license suspension and 5 SESO penalty points [10]
Hungary Legal, no limitations
India Legal
Iceland Legal Radar jammers are illegal.
Ireland Illegal (Republic of Ireland, Éire) Law Refers to 'Speed Meter Detectors', Introduced 1991. No fixed penalty for possession, expect confiscation and Hefty fine.[11]
Israel Legal Some cellular providers such as Pelephone actually provide radar detecting as a service powered by GPS [12]
Japan Legal
Jordan Legal[13]
Latvia Illegal K, POP Ka
Lithuania Illegal X, POP K, Laser
Malaysia Illegal to possess, purchase, sell or use. Heavy fines apply. Radar detectors are also prohibited items under customs laws.
Netherlands Illegal 250€ fine and seizure of the device (since 2004)[14]
New Zealand Legal Ka and Laser used also fixed speed camera and speed camera vans (Low Powered K Ban)
Norway Illegal to use. (Legal to own, sell, and buy) 8000-10000 krone fine and seizure of the device.[15]
Pakistan Legal
Poland Legal to own, illegal to use in a moving vehicle Jammers illegal X, K, Pulse K, Ka Narrow, Laser
Romania Legal since 2006 Radar jammers still illegal[16]
Russia Legal Instant-On (Pulse) X, POP K, Laser (0,8 mkm)
Saudi Arabia Illegal
Serbia Illegal to use, possess, sell or advertise Illegal to use or have in possession in a vehicle in traffic, to sell or advertise: an apparatus or any other means of detecting or interfering with operation of vehicle speed measuring devices, or any other apparatus used for discovering and reporting traffic violations [17]
Singapore Illegal to possess, purchase, sell or use. Heavy fines apply. Radar detectors are also prohibited items under customs laws.
South Africa Illegal to use in a moving vehicle Importing a unit is permitted under South African customs regulations.
Switzerland Illegal Radar detectors are confiscated and destroyed. The use of any GPS-based device to locate speed cameras is also illegal.
Turkey Illegal Radar jammers are illegal
UAE Illegal
United Kingdom Legal Legal to own, but technically illegal to use under the Wireless Telegraphy Act 1949 until 1998, due to legal loophole causing them to be legalized suddenly.
United States Law varies from state to state, but detectors are generally legal in private vehicles under the Communications Act of 1934[18] and illegal in commercial vehicles by DOT regulation (49 CFR 392.71). Exceptions: Confiscation and/or destruction of the detector was once a common practice but lawsuits raised by drivers arguing violation of property rights have resulted in temporary removal while a citation is written, then return of the device after its description (make, model and serial number) has been entered on the ticket - usually for speeding and possession/operation of detector. Use of a radar/lidar detector on a military installation is prohibited. Persons entering a military installation with one visibly mounted to the sun visor or windshield will be asked to remove it and put it away. Those who refuse will be denied entry onto the installation at that time. Military law enforcement may not soley stop a vehicle for a detector being in use but, along with being stopped for another moving violation, the person using the detector may be ordered to report the violation to his/her unit commanding officer (active duty ONLY). No traffic citation may be issued against military dependents, civilian workers or retired persons even if the military installation is in a state or district which prohibits the use, possession and/or transportation of such devices. Military law enforcement cannot enforce civilian ordinances, state laws, etc.

See also


  1. ^ Radar Detector Detector (RDD)
  2. ^ Passive Radar Jammers
  3. ^ FCC Ban
  4. ^ "Road Traffic (Miscellaneous) Variation Regulations 2003". SA State Government. 2003. http://www.legislation.sa.gov.au/LZ/V/R/2003/ROAD%20TRAFFIC%20(MISCELLANEOUS)%20VARIATION%20REGULATIONS%202003_58/2003.58.UN.RTF.  
  5. ^ "Traffic Infringement Notice". Department of Infrastructure, Energy and Resources. http://www.transport.tas.gov.au/safety/traffic_infringement.  
  6. ^ "De Standaard 2006-07-20". De Standaard. 2006-07-20.  
  7. ^ Travel Canada's Northwest Territories
  8. ^ United States Department of State: Consular Information Sheet for Canada
  9. ^ German Bussgeldkatalog
  10. ^ Greek Ministry of Transportation - The Greek driving laws
  11. ^ Irish Statute Book S.I. No. 50/1991 — Road Traffic (Speed Meter Detectors) Regulations, 1991.
  12. ^ Radar Detecting Service Advertisement by Pelephone
  13. ^ "Jordan Driving Laws" (PDF). http://www.traffic.psd.gov.jo/images/docs/new%20law.pdf.  
  14. ^ "Dutch Ministry of the Attorney General - Speed and violations". http://www.om.nl/onderwerpen/verkeer_(bvom)/veelgestelde_vragen/snelheid_en/.  
  15. ^ "Ofte stilte spørsmål om fart" (in Norwegian). politiet.no (Norwegian Police). 21 August 2009. https://www.politi.no/rad_fra_politiet/trafikksikkerhet/fart/Tema_182.xhtml. Retrieved 24 November 2009.  
  16. ^ "OUG 63/2006 Art. 44 Al.4-5". http://www.politiaromana.ro/DPR/oug_63_2006.htm.  
  17. ^ "Zakon o bezbednosti saobraćaja na putevima, SLUŽBENI GLASNIK: 41-09 (Art. 29)" (PDF). http://www.parliament.gov.rs/content/lat/akta/akta_detalji.asp?Id=597&t=Z#.  
  18. ^ U.S. RADAR Detector Laws
  19. ^ "NY State Law Database Broken Link". http://public.leginfo.state.ny.us/LAWSSEAF.cgi?QUERYTYPE=LAWS+&QUERYDATA=$$VAT375$$@TXVAT0375+&LIST=LAW+&BROWSER=38582402+&TOKEN=40728386+&TARGET=VIEW.  
  20. ^ "Connecticut Repeals Detector Ban". http://www.adrawa.com.au/Surveys%20and%20Studies/Studies/Radar%20Ban%20Repealed%20Article.pdf.  


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