2pcs Solar Powered Car Alarm System,Vehicle LED Light

The radar velocimeter calculates the movement speed of the object to be measured based on the calculation of the frequency shift of the received reflected wave. The radar beam irradiation surface is large, so the radar speed measurement is easy to capture the target without precise aiming. Radar equipment can not only be fixed on the road, but also can be installed on patrol cars. The detection of vehicle speed in motion is a very important part of "mobile electronic police"; secondly, the error of radar speed measurement is about: vehicle speed V increase or decrease 0.1031 %V can fully meet the requirements of traffic violation investigation; the international use of radar speed measurement has a history of more than 20 years, and the technology is mature and the cost is low. Judging from the current situation, Beijing's urban roads are still dominated by backward speed measurement, but a small number of forward speed radar speedometers have appeared. On the highway, there are many positive speed measuring devices. Backward means that the direction of the radar wave and the camera is the same as the direction of the car. When the vehicle is speeding, the camera shoots the rear license plate of the vehicle. The forward direction is that the direction of the radar wave and the camera is opposite to the direction of the car. When the vehicle is speeding, the camera shoots the front license plate of the vehicle.
The principle of the radar detector is very simple, that is, after receiving the radar signal, it will immediately alarm, prompting the owner to slow down. Its price is generally 800 yuan to 5,000 yuan, and the performance is also very different. The biggest difference is that the frequency bands of the radar waves that can be sensed are different. Because the radar speed measuring equipment for roads in various cities in my country is from different countries, the radar frequencies used are mostly different, and some of the same cities are equipped with radar speed measuring devices with different frequency bands from three or four countries. Low-end radar detectors often can only sense radar waves in one frequency band, while high-end radar detectors can sense radar waves in multiple frequency bands. In addition, the sensing distance also reflects the performance of the radar detector. If the sensing distance is too close, the car owner has no time to slow down and has already been photographed; if the speed is too fast, it is easy to cause a rear-end collision. High-end radar detectors can sense radar waves at about one kilometer, while poor ones can only sense at about 200 meters. 1. The detector must be placed in the correct position in order to exert the maximum effect: (1) The detector should be fixed on the front windshield of the vehicle, or the detector should be fixed on the dashboard with double-sided nylon tape, and the receiving antenna should face the front of the vehicle. direction. The detector should be in a horizontal position or the receiving antenna should be slightly tilted up.
(2) The receiving antenna must face the front windshield and cannot be blocked by the wiper, otherwise the receiving effect will be affected.
2. A car with a metal anti-riot heat shield (or its own anti-riot function) on the front windshield will affect the response distance of the detector.
3. It is strictly forbidden to use two detectors together
4. Urban clutter interference