[百問] Speeding Red List Don't Come (Part 1) There are different types of speed cameras? How to buy a speedometer?

Many people go on holiday for the New Year, and the last thing they don’t want to encounter after the holiday is to receive a bunch of speeding tickets, especially the speed limit of 50km/h in urban areas is unacceptable. In order to avoid this kind of thing, It is recommended to install a speed warning device on the car that can actively remind the car owner to pay attention to the speed camera, or a laser shield specially designed for the police laser gun. How to buy it is correct? Let me give a good introduction.

Question 1: What is a radar speed camera and why can it measure the speed of the vehicle?

At present, the police speed measurement system can be roughly divided into two categories, namely radar speed measurement system and laser speed measurement system. Among them, the most basic principle of radar speed measurement is to use the so-called "Doppler effect", which uses a device that continuously emits radio waves to launch objects. The frequency of the reflected radio waves will have different effects due to the distance between the object and the radar. The farther the distance is, the longer the frequency is. The radar speed measurement system uses the detected frequency to change the speed to know the difference between the object and the radar. The relative moving speed between the radars, and then interpret whether the vehicle is overspeeding, the principle is similar to the radar system of a warship.

The radar speed camera appears mainly in two ways: placed in a fixed photo pole, or placed on a tripod and placed in a flowing manner. The former is better for most car owners to guard against, but a mobile tripod with random and indeterminate points is used. The prohibition method of placing, unless the car is equipped with an overspeed warning device and a product with a still-pipe receiver, it is easy to be accidentally banned by taking pictures, which is why you should buy an overspeed warning device.

It is worth mentioning that radar speed cameras cannot take photos of running a red light. Other auxiliary equipment is required to detect whether the vehicle has crossed the line at a red light. Generally, car owners cannot distinguish the difference in appearance. The key is to fix the position of the pole camera. At intersections, in addition to shooting speeding, this group of cameras will basically shoot vehicles running red lights. As for the laser speed measurement system, there is an introduction after the article, you can continue to read.

How to choose an overspeed warning device so that you can spend your money on the knife edge?

As for the purchase of the speed warning device, the author suggests that if the budget is insufficient, you can start with a single-model GPS speed warning device. The operating principle of the GPS satellite positioning warning device, as the name implies, is that the host uses the many satellite signals above our heads to find the vehicle coordinates (usually three satellite signals are used to determine the vehicle coordinates), and then use the built-in map program of the host. , to grasp the relative position of the vehicle and the speed camera to give a warning. When the vehicle approaches the camera stick, it will emit a countdown relative distance sound until it passes, and as long as the vehicle speed exceeds the speed limit at that time, the host will also emit a low sound to warn the owner. If you are already speeding, the warning function can be achieved, so that the driver can decelerate early to avoid receiving a red ticket.

But is it just that? In fact, it is not, because since the relative position of the vehicle and the speed camera can be determined, as long as the built-in map program function is strengthened, can the relative position of the vehicle and tunnels, interchanges, toll booths, and rest stops also be determined? And not only that, the current speed, direction and even altitude of the vehicle can be provided through this host, so that this warning device can not only provide a warning function, but also become a device that reminds you where to go at any time. Resting, when to turn on the lights, and prepare to enter the tunnel, is the miniature satellite navigation machine quite user-friendly? In addition to the above-mentioned functions, some models with more powerful functions can also set the speed limit. Unless the set speed is exceeded, the host will not issue a warning sound, which reduces the occurrence of disturbing driving attention.

As for the so-called single-model products, it refers to only the GPS warning device in the car. Some have built-in still-pipe radar signal receivers, which can grasp the position of the mobile tripod camera, but some lower-end products do not have built-in guided waves. However, you can only passively warn car owners through GPS + map information like satellite navigation. The price of the former is often much higher than that of the latter, and many functions of the latter can be replaced by mobile APPs. Therefore, if you want to buy a single model product, it is recommended Buying products with built-in stills that can detect tripod cameras will be more resistant to the ban of mobile cameras. Compared with stand-alone products, it is a separate product.

What is a still-pipe receiver?
This part is used to receive radar signals, so that the position of the mobile tripod camera can be grasped. Some are built in the overspeed warning device. Longer warning distance. But not all overspeed warning devices are equipped with stilling tubes, so make sure before purchasing.

Question 3: What is the so-called separate overspeed warning device?

In simple terms, the separate speed warning device uses an indoor warning host and an external radar wave receiver to detect the photo radar wave, and the signal transmission between them is achieved by wired/wireless transmission. The purpose is to make the signal detection of the camera more accurate.

The advantages of this technology are as follows. First of all, it can avoid the problem of signal blocking by heat insulation paper. For traditional single-type speedometers, since the radar radio wave receiver (ie still-pipe) is located in the indoor main unit, when the vehicle front bumper sticks When there is metal heat-insulating paper, it is possible that the radar wave cannot be fully penetrated into the car, resulting in the warning distance of the speedometer being too short. The dilemma of paying red bills.

In addition, since the signal receiver is installed outside the car, the store can adjust the machine to the best receiving angle during installation to increase the warning distance and avoid the past jokes that a single host is "received upside down" on the sun visor, and At present, many new K-band fixed cameras have a relatively low angle of emission radio waves. If there is no appropriate receiving angle to respond, the response distance is usually very short, and the purpose of installing a speedometer is lost.

It is worth mentioning that if the wireless transmission technology is adopted, the problem of mutual wiring between the inside and outside of the car can be reduced, which not only saves the complicated installation work, saves time for the car owner, but also reduces the number of wires going around under the dashboard. Troubled, the installation can be completed without destroying the overall visual experience in the car, and the display screens of some indoor units are very ornately designed, which can add a lot of sense of technology in the car interior. This kind of product is a high-end GPS speeding warning. device, so the price is not low.

[百問] Don't come to the speeding red list (Part 2) What is a laser gun? How to buy a laser shield?