Understanding Radar and Laser Detection
Radar
Radar guns utilize the “Doppler principle” to determine speed. They transmit radio waves at microwave frequencies, and when these waves strike a moving object, they are reflected back to the radar gun at a slightly different frequency. The radar gun then uses the difference between these two frequencies to determine your speed. Radar guns operate on radar ‘bands’ which are a range of different microwave frequencies. Different Radar Bands are outlined below.
Radar Bands
There are four different radar bands used worldwide, these are:
X Band – NOT USED in Western Australia
K band – USED by police in Western Australia
Ka Band – USED by police in Western Australia
Ku Band – NOT USED in Western Australia
X and Ku Bands are used in America and Europe respectively and are not used by any police in Western Australia.
There are two radar devices used by police in Western Australia which work on two different bands. When your detector alerts you to the band it is detecting, you should be looking out for the radar device corresponding to that band. The radar devices and their bands are listed below.
- K Band is most commonly used by police in Western Australia in the form of moving in-car radar. Many police cars contain a radar gun used to catch speeding vehicles. These radar guns can catch you speeding from either behind or coming from the opposite direction.
- Ka Band is used by police in the form of the Multanova. These are the most common radar device you will find, particularly in Perth. Emitting only very low power, multanova’s are VERY hard to detect, which is why we choose to only sell the Passport 8500 X50 and Valentine 1, which have the best Ka band range available today.
Laser
Laser guns do not use the doppler principle like radar guns do. Instead the laser gun sends out a pulse, and calculates the “time of flight” for the pulse to be reflected back to the laser gun. Since the speed of light is a known value, the distance between the laser gun and its target can be calculated by the time of flight. The laser gun takes multiple distance measurements, and by comparing the different distance measurements over time, it can determine the speed of the target.
The Laser gun used by police in Western Australia is the LTI Ultralyte. Laser is very difficult to detect. This is because of two factors:
1. Beam Width – Unlike radar the signal or beam emitted from a laser gun is a lot smaller than that of radar. For example, at a distance of 200 meters, the beam width of the laser gun is only 59cm.
2. Nature of signal – A laser signal is only active when the operator pulls the trigger and therefore the beam can only be detected, when it is already getting your speed. Because of this, any laser alert must be treated very seriously.
For more information about radar or laser please visit www.nomorefines.com.au
