What is a radar Detector?

A radar detector is a small electronic device used by some drivers to detect the presence of police radar units and laser speed cameras and laser speed guns. Ideally, the device will pick up the radar/laser gun's signal before the driver speeds past the police officer using it. Avoiding a laser gun speed reading using a radar/laser detector is a difficult feat, because a laser speed reading is obtained in milliseconds, long before the driver has had time to react. In contrast, radar guns spray a radar sign in a fan shape which can barely be called directional. This spray of radiation can be picked up by radar detectors at reasonably long distances, giving the driver enough time to react and check speed if necessary.
Radar for speed detection is falling out of favour with most police departments, due to inherent errors and reflection that make this type of speed detection prone to errors and false readings.
Radar detectors and laser detectors can best be described as tolerated in some states and countries, and illegal in other jurisdictions. There is no restriction on the use of radar detectors or laser jammer in Western Australia. Most drivers who use one keep it attached to the visor or other inconspicuous area.

Radar Detector Detectors:

Some makes and models of radar detector can be vulnerable to detection by a device used by police called a “Radar Detector Detector” (R.D.D.) in states where radar detections are illegal. This is a rather sneaky piece of equipment which is capable of detect the functioning radar detector and alert the office to your equipment. It is most important for drivers to purchase a radar detector that is NOT detectable by police R.D.D devices.

Function:
 
A very basic radar gun sends out a radio signal at a specific frequency, which bounces off a metallic targeted object (a car's body or number plate for example) and returns to the radar gun. This signal moves at the speed of light, so a computer unit can calculate the time it takes for a signal to return. Radar guns typically take slightly longer to generate a speed reading than laser guns. This is most likely due to error control functions within the gun that require a consistent reading over a short time period before a reading is displayed. If the target object is moving towards the radar gun, the returning signal frequency becomes higher due to a phenomenon called the Doppler shift. This means a moving police vehicle can accurately calculate the speed of a car approaching it. Police laser guns are required to remain stationary by the side of the highway to detect speeders; however there are some models of radar detection such as “moving mobile radar” fitted to a police car. The mobile radar is able to take into consideration the speed of the police vehicle when calculating the speed of a targeted vehicle. 

A radar detector is tuned to the same radio frequencies used by most radar guns, In the same sense that a car radio can pick up the specific signal on an AM or FM channel, a detector can sense an active signal on a police radar frequency before the car gets into its enforceable range. When activated, a radar detector sends out both an audio and visual signal to the driver, who should have enough time to slow down to a legal speed. 


Detection Distances:

Alert distances depend heavily on the police officer's operating the radar gun. A smart police officer will point the radar gun at the ground while waiting for a target vehicle to approach to within the speed detection zone before raising the gun to target the approaching vehicle. Using this method, a driver will have little if any time to react. Fortunately, many police officers hold their radar guns up for too long, there-by sending stray radiation signals far down range which can be easily detected.  The same issue occurs with the use of mobile radar. Prescient police officers, leave the radar system on standby until a vehicle is within a reasonable range, then targeting the vehicle with a short bust, to obtain an accurate speed reading.  If a police car comes up quietly on a speeding car before activating the mobile radar, a radar detector won't offer much protection.
Modern radar guns and speed detections systems use “quick burst” radiation to avoid alerting radar detector users down range.  Sophisticated radar detector can still pick up on these quick burst signals if there are enough reflection off metal objects or a good line of sight. Considering that an average speeding ticket can cost quite a bit of money and a significant increase in insurance rates, the price of an advanced detection device may seem worthwhile to those drivers who tend to stray over the limit.
The latest trend in speeding detection uses laser light instead of soundwaves. A system called LIDAR  (LIght  Detection And Ranging) can be set up by law enforcers to detect speeders automatically through more accurate laser measurements. Because the laser signals are so narrowly focused, a standard radar detector cannot sense the signal before arrival. Although a radar/laser detector may pick up a laser speed gun, there will not be enough time to do anything about it. A speed reading will be obtained in milliseconds. In this situation a radar /laser detector would more accurately be called a “Speeding fine detector” a useless brick better used as a door stop.

 

The only option to drivers is to use a “laser jammer” or more accurately called a “laser black-out device” A device like the HP-905 from Blinder Australia can trick a laser gun into thinking that the car it is fitted to is INVISIBLE. The 3 or 4 seconds warning before automatic switch will often afford you time to slow down and avoid a speeding fine.
As with radar detectors, poor quality laser gun jammers can be detected on some models of laser gun giving off jamming codes. The Blinder HP-905 does not give off any jamming signals and is capable of jamming all laser guns used in Australia. You can own a high quality laser “black-out” device at a price that will make you smile. Blinder.com.au