Speeding has always been the main cause of accidents and deaths on our highways, which requires our traffic law enforcement departments to use technical equipment that can prevent habitual violators from speeding - speed guns, which can help save lives. There are currently two common types of speed guns: radar speed guns and laser speed guns.
Radar speed gun
The principle of radar speed measurement is to apply the Doppler effect, so it has the following characteristics:
(1) The radar beam has a larger irradiation area than the laser beam (ray), so radar speed measurement is easy to capture the target without precise aiming;
(2) Radar speed measurement equipment can be installed on patrol cars to detect vehicle speed while moving, which is a very important component of "mobile electronic police";
(3) The fixed speed measurement error of radar is ±1 km/h, and the measurement error during movement is ±2 km/h, which can fully meet the requirements for traffic violation investigation and punishment;
(4) The electromagnetic wave beam emitted by the radar has a certain angle, so the effective speed measurement distance is closer than that of laser speed measurement, and the maximum speed measurement distance is 800 m (for large vehicles).
(5) Radar speed gun technology is mature and the price is moderate.
(6) The angle of the radar speed meter's beam is a very important technical indicator. The larger the angle, the more susceptible the speed measurement accuracy is; conversely, the impact is smaller.
Radar speed meters are used by my country's public security traffic management departments as a tool for speeding penalties because of their low price, accurate speed measurement, ease of use, and ability to detect vehicle speed during movement. Currently, the hot-selling brands and models on the market include: Stalker PRO2, Stalker LIDAR XS, Tracer sra3000, Bushnell 101911, Bushnell 101921, and Hotwheels J2358.
Laser speed meter
The laser speed meter uses the principle of laser ranging. Laser ranging is to determine the distance between the object being measured and the test point by emitting a laser beam to the object being measured, receiving the reflected wave of the laser beam, and recording the time difference. Laser speed measurement is to perform laser ranging on the object being measured twice with a specific time interval, obtain the moving distance of the object being measured during the period, and thus obtain the moving speed of the object being measured. Laser speed measurement has the following characteristics:
(1) The laser beam emitted by the laser speed meter is extremely fine (the divergence angle of the laser emission part is 3mrad), and the diameter is only 30cm at 100m, so the irradiation area is small and can be aimed at any target.
(2) The speed measurement distance is far from the effective distance of radar speed measurement, and can measure 1000m away. It can capture from a long distance without being detected (of course, considering the camera lens, it is normally captured at 100m to 150m).
(3) Fast response, single speed measurement time is 0.3 seconds.
(4) In view of the principle of laser speed measurement, the laser speed meter cannot be used in motion and can only be used in a stationary state; therefore, traffic police generally put the instrument on the patrol car and use it when the car is parked.
(5) Because the laser beam of the laser speed meter is extremely fine and its response time is extremely fast, the general electronic detectors on the market are useless for interfering with and detecting the laser speed meter.
(6) The optical speed meter is a new type of traffic management law enforcement tool. It provides a reliable technical evidence collection method for the governance of speeding violations. It overcomes the shortcomings of radar speed meters, such as slow speed measurement, wide beam, and the harmful effects of radiation on human health. Therefore, it has advantages that radar speed meters cannot match. It can measure speed and distance, and has strong functionality. It can effortlessly detect the speed of a single vehicle or even a motorcycle on a busy multi-lane road. Traffic law enforcement departments in some parts of my country have also begun to introduce and use laser speed measurement devices. With the widespread use of new equipment, radar detectors alone can no longer provide sufficient protection. It can be seen that laser speed measurement will be more and more widely used in future traffic law enforcement.
The hot-selling laser speed meter brands and models on the market are American LTI Truspeed, TruSpeed LR, TruSpeed DC, TruSpeed S, TruSpeed Sxb, and TruSpeed Se, but these products are expensive, with the cheapest starting at 40,000 yuan. Now Oonica Outdoor Optics has developed two new laser speedometers, the LS320 handheld laser rangefinder and the LSP320 laser speedometer with shooting function. The prices are lower than those of the speedometers produced by LTI Laser Technology Company in the United States.
Summary: Existence is reasonable. The two types of speedometers have their own advantages. The editor thinks that if the speed measurement accuracy is low and the purchase budget is low, the radar speedometer can be selected; if the speed measurement accuracy is high and the product life is strict, the laser speedometer should be selected.