Questions and answers about police radar guns 

On this page you will find the more often asked questions about technical and legal aspects of police radar guns, radar-detectors and other combined questions. If you have not found the answer you need, please send us your question per e-mail:
Your question about radar gun,  Your question about radar-detector

• What is the police radar gun performance?

A radio-locating police radar gun radiates electromagnetic signal, that reflects from metal objects. Reflected signal is again received by the radar gun. If the object moves than frequencies of radiated and reflected signals differ. The difference shows the object speed.

• What frequencies are used?

There are several frequency ranges on which the radar guns can perform. This ranges are specified by international agreements. In Russia The State Committee of Radiofrequencies makes decision about giving a frequency for any purpose. Internationally there are 4 ranges for road radar guns: 
Õ-range (10.525 GHz +25 MHz), 
Ê-range (24.15 GHz + 100 MHz), 
Êà-range (33.4 GHz - 36.0 GHz),
La - laser range.
Only 3 of them are allowed in Russia: Õ, Ê, La - ranges.

• What is the distance of police radar gun detection?

In practice the distance of detection depends on many conditions: road relief, weather conditions, accuracy of radar gun pointing. Rain, snow, smog decrease the detection distance. The maximum distance on which the radar gun provides the speed measuring is 500-800 meters. GOST specifies the detection distance not less than 300 meters. That means that the radar gun that can't measure speed on 300 m distance, can't have calibration and can't be used. However, the radar gun can be used on the distance that is more or less than 300 m. In case of speed measuring, precision requirements are performed independently from target distance.

• What does term false police radar gun mean?

In several countries (e.g. Germany) with a view to have the secure road situation the police place so called false radar guns in dangerous parts of the road. That are the devices, that imitate radar gun signal. When the radar-detector abrasion takes place the drivers decrease the speed and this decreases danger.

• What photoradar means?

In this devices the radiolocation speed meter is combined with photo, video-camera or a computer when the number of violator car is fixed. 
The picture where date, time and speed are shown, is a proof of exceeding speed fact (also in court). Photoradar can work in manual or automatic modes. First they appeared abroad. Then they begin to be used in Russia (e.g. videoregistrator KADR-1 together with radar gun ISKRA-1).

• Why is Safety Alert system is used?

Different variants of this system are used to warn the drivers about possible road dangers (accidents, repair works, moving of special repair cars, etc). Radio bacons are used that radiate special signal that an be found by a radar-detector with Safety Alert system. It doesn't work in Russia.

• What types of radar guns does the police use in Russia?

Both home (Barier, Socol, ISKRA-1) and foreign (ENFORCER, SpeedGun, PYTHON) are used in Russia. Most of all radar guns in Russia work in K-range. However, in modern radar guns other ranges are used. The ISKRA-1 police radar gun also works in K-range and its technical features decrease effectiveness of foreign saperheterodyne radar-detectors.

• Is it possible to measure speed in moving?

Some types of the radar guns allow to measure speed in moving patrol car. The information about patrol car speed the radar gun receives from reflected signal from the road. ISKRA-1 allows to measure speed of on-coming and head targets in moving, heading along the patrol car and visa versa (through windscreen or back window). 

• What is the impulse mode of radar gun performance?

Many types of radar guns allow to measure speed by short impulses (shots). Usually such shots are performed directly by car approaching that troubles performance of the radar-detectors.

• Who does impulse radar gun work?

Many used radar guns can work in automatic and impulse modes. In impulse mode radar gun needs a second to fix the speed. During that the radar gun performs several measures and displays the results, if near results don't differ mush. Is the results differ much the procedure starts over. If a radar-detector has good sensitiveness it will be possible to receive the signal from shot on car driving before. The radar-detector must have high processing speed.

• Why is timer used?

When the radar gun fixes the exceeding speed the timer launches. The results are necessary prove the violator that it is his speed. The timer performance is limited to 10 min.

• Does the speed measuring depend on moving direction?

Modern models of radar guns have a possibility to select targets by moving direction (head, on-coming) with the corresponding indication. If the measuring is held with an angle there can occur some mistakes and the mistake will be higher if the angle is big. Why can't some foreign radar-detectors, such as (Cobra, Whistler, etc ) react on ISKRA-1 signal right? Some people think that it is because K-range. It is not right Cobra and Whistler select this range effectively. The problem is that these radar-detectors have good scheme of noise immunity that is based on short impulses filtration principle. Thus, the radar-detector selects the radar gun signal but consider it like a noise and give no information about the signal.

Questions about radar-detectors >>