The word "radar" is an acronym for "Radio Detection and Ranging. With police radar, that moving object is your car. Radar units generate the waves with a transmitter.
When they bounce back off your car, they are picked up and amplified by a receiver so they can be analyzed. The analysis is then reflected in a speed-readout device. Radar systems use radio waves similar to those involved in AM and FM radio transmissions, but with a higher frequency—up to 24 billion waves per second as compared to one million per second for AM radio. Although radar signals can be bounced off stationary or moving objects, they cannot be bent over hills or around curves.
To clock your speed with radar, this means you must be in an officer's line of sight. However, don't expect to see the radar unit. Officers can hide it behind roadside shrubbery or stick it out unobtrusively from behind a parked car. Here are some of the more common malfunctions and sources of inaccurate readings with radar device:. Many of these defenses are applicable only in certain situations.
But, anytime an officer uses a radar to clock a driver's speed, there's the potential for a defense based on inproper calibration. Laser detectors are the most recent addition to the traffic officer's arsenal of speed-measuring devices.
Built to look and act like a hand-held radar gun, a laser detector uses a low-powered beam of laser light that bounces off the targeted vehicle and returns to a receiver in the unit. The unit then electronically calculates the speed of the targeted vehicle. Laser detectors are supposedly more accurate than radar units.
One advantage for police officers of the laser gun is that the light beam is narrower than a radar beam, meaning that it can be more precisely aimed.
This is true even though laser detectors use three separate beams, because the combined width of the three beams is still much narrower than a single radar beam at the same distance. This technology reduces, but does not eliminate, the chance that the speed of a nearby car will be measured instead of the speed of the car at which the operator aims the gun.
Laser detectors measure distance between the gun and the target car using the speed of light and the time it takes the light, reflected off the target vehicle, to return to the laser gun. The detector makes about 40 of these distance measurements over a third of a second, then divides the light's round-trip distance by the time, to get the speed. This means to be accurate the officer must hold the combined beams on the same part of the car during the test.
While this is easier to do with radar because of its wide beam, it is tricky to do this with a narrow laser beam. Also, it's impossible to be sure that that the officer has been able to accomplish this feat because the officer can't see the beam. It's also possible especially in heavy traffic for one beam to hit the target car and another beam to hit a nearby car. The chances of this happening increase with traffic density and the distance between the laser unit and the measured vehicle.
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The attorney listings on this site are paid attorney advertising. In some states, the information on this website may be considered a lawyer referral service. Please reference the Terms of Use and the Supplemental Terms for specific information related to your state. Grow Your Legal Practice. Meet the Editors. If you want to fight your ticket, you should find out how your speed was determined.
If you want to fight a speeding ticket, there are two things you must know first: whether you charged under an "absolute," "presumed," or "basic" speed law how the officer measured your speed —through pacing, aircraft, radar, laser, VASCAR, or other means. Pacing Many speeding tickets result from the police officer following or "pacing" a suspected speeder and using his or her own speedometer to clock the suspect's speed.
Here are some things to consider for fighting a speeding ticket based on pacing: Road configuration may help prove inadequate pacing. Hills, curves, traffic, interchanges, traffic lights, and stop signs can all help you prove that an officer did not pace you long enough.
For example, an officer following your vehicle a few hundred feet behind will often lose sight of it through a curve. Similarly, if you were ticketed within feet of starting up from a stop sign or light, it could case into doubt whether the officer can prove having paced your car for a reasonable distance. The farther back the officer, the less accurate the pace. X band radar is prone to interference from automatic door opening systems.
K band K is short for Kurz, which is the German word for short and Ka K-above band radar are less resistant to atmospheric absorption than X band and less effective over long distances. Most of the new radar guns such as the Stalker II and the Kustom Talon use Ka band signals, so if your detector goes off, you know you need to react right away. The high-sensitivity radar receiver in a radar detector is tuned to pick up extremely low-level signals and alert you that radar is in use.
You need to act quickly when a radar detector goes off. Your local specialist mobile enhancement retailer can help you choose the perfect portable or custom-installed radar for your application and ensure that the system is installed cleanly. This article is written and produced by the team at www. Reproduction or use of any kind is prohibited without the express written permission of 1sixty8 media. Enter your email address to subscribe to our website and receive notifications of new posts by email.
Email Address. There are three bands of radar that are used by police officers in North America. The first is X-band. X-band is the oldest band of radar, scanning at about Although X-band is not commonly used nationwide, it is still used by police officers in New Jersey and Ohio.
K-band is the second band of radar, scanning at about K-band is the most widely used band of radar, not only by the police but also by other sources. K-band is being emitted by automatic doors, security systems, and cars with collision avoidance and lane departure warning. The third band of police radar is called Ka-band. Ka-band scans between Violations are automatically attributed to specific vehicles and documented in a digital case file. The system is ready for use without tedious site calibration.
No additional triggering equipment such as light barriers is necessary. We have seen how police use traditional radar as well as new laser technology to catch drivers speeding. As it turns out, conventional radar is relatively easy to detect. The simplest radar detector is just a basic radio receiver, something like the one you use to pick up FM and AM radio stations. The receiver in a radio is designed to pick up signals in the AM and FM frequency spectrum, whereas the receiver in a radar detector is tuned to the frequency range used by police radar guns.
These devices are more difficult to evade than traditional radar because the beam is much more focused. Therefore it is a must to have a high quality, high sensitivity and fast reacting radar laser detector. Australia New Zealand. Facebook YouTube. How does a Speed Camera or Radar Gun work? The concept of measuring vehicle speed with radar is very simple.
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