1. Using the principle of infrared ranging or laser ranging
The principle of ranging can basically be attributed to measuring the time required for light to travel to and from the target, and then calculate the distance through the speed of light and the atmospheric refraction coefficient. Because it is difficult to measure time directly, it is usually to measure the phase of the continuous wave, which is called a phase-measuring rangefinder. Of course, there are also pulsed rangefinders. It should be noted that the phase measurement does not measure the phase of the infrared or laser, but measures the phase of the signal modulated on the infrared or laser. The construction industry has a handheld laser rangefinder for house measurements that works the same way.
2. The plane of the object to be measured must be perpendicular to the light. Usually, a total reflection prism is required for distance measurement, and the rangefinder used for house measurement is directly measured by reflection from a smooth wall, mainly because the distance is relatively close, and the light reflected back signal Strong enough. It can be known from this that it must be vertical, otherwise the return signal is too weak to be able to intelligently determine the accurate distance.
3. It is usually possible to measure the plane of the object as diffuse reflection. In practical projects, a thin plastic plate will be used as the reflective surface to solve the problem of serious diffuse reflection.
4. The entertainment-grade products of the pulsed laser rangefinder can achieve a display accuracy of 1 meter, a measurement accuracy of ±1m, and a measurement-grade product display accuracy of 0.1m and a measurement accuracy of ±0.15m.
5. The accuracy of the phase laser rangefinder can reach 1 mm error, which is suitable for various high-precision measurement purposes.
