Only Speedar shows you the direction of the target you are measuring. This means you can now use radar with confidence on roads with 2 way traffic.


For the first time ever radar can be used with confidence on roads with opposing traffic flows. Speedar’s display clearly shows in which direction a vehicle is being tracked. The internal clock shows the time at which a reading was locked. An internal memory holds the speed limit for the road being checked and displays it when a reading is locked.

An internal memory holds the speed limit for the road being checked and displays it when a reading is locked.

Specification Brochure


Speedar can be used anywhere that the speed of an object is to be measured, the obvious uses are measuring the speeds of cars or trucks, however it is also quite capable of measuring the speed of balls in flight and is often used for measuring the speed of kicks in football amusements and for the speed of tennis serves in matches. For this use it is vastly superior to laser speed measurement as it is almost impossible to keep a laser trained on a moving ball. Naturally it will also measure the speed of boats or trains.

How Speedar works

The Speedar hand-held traffic radar equipment is based on the well-known and legally-accepted principle known as the Doppler effect. This is a fundamental law of physics first demonstrated by the Austrian physicist Christian Doppler in 1842. It applies to the alteration in frequency caused when a wave of energy of any sort is reflected by or transmitted from a moving surface. Everyone is aware of the operation of this principle in everyday life, albeit unconsciously. For instance, its effects are shown whenever a vehicle passes whilst sounding its horn. As the vehicle approaches, the sound from its horn is perceived to be at a higher pitch than when it is receding. As applied to traffic radar, the Doppler effect means that a radio frequency signal emitted from a stationary radar and reflected from a moving target will experience a change in frequency of the reflected wave directly proportional to the speed of the target, relative to the radar transmitter. In whichever direction the target is moving, the change in frequency will be the same for the same relative speeds. The difference between an approaching and a receding target being that an approaching target will give a reflected frequency higher than the transmitted frequency, a receding target will give a reflected frequency lower than the transmitted frequency. The Speedar transmits at 24.10GHz. The transmitted microwaves strike a moving target vehicle and some are reflected back. If the vehicle is approaching, more waves, ie. a higher frequency, will be reflected back to the radar; if the vehicle is receding, less waves, ie. a lower frequency, will be reflected back to the radar. The difference in frequency between the transmitted signal and that received back after reflection is known as the Doppler shift. This frequency shift falls within the audio band for the transmitter frequencies and vehicle speeds for which the equipment is used. The circuitry in the Speedar compares the frequency of the transmitted and reflected signals in a homodyne mixer and from the Doppler audio difference frequency that is detected, the circuitry calculates and displays the speed and direction of the moving target. The Doppler frequency is calculated according to the following equation.


Where fdop= the doppler frequency in Hz F= the transmitter frequency in Hz V= the speed of the target in metres/second Cos Θ = the angle of travel of the target relative to the radar