What are all the technical principles of the laser range finder?
Principle of pulse method laser distance measurement technology:
Phase method is similar to the method used in ultrasonic speed ranging, * large measuring distance is usually a few hundred metres, can more easily reach the millimetre order of magnitude, but in accordance with the method of the design of the rangefinder * large measuring distance is limited, not scalable. The method is mainly used in foreign countries more widely. The pulse method of laser ranging generally uses infrared laser, including near-infrared laser and mid-infrared laser. This band of laser has visible and non-visible points. And the rangefinder based on this technology has low coherence requirements, fast speed, simple implementation structure, high peak output power, high repetition frequency and wide range, so this project uses the pulse method to design the handheld laser rangefinder.
The principle of the phase method laser rangefinding technology:
The mainstream laser rangefinders in the market are phase method based laser rangefinders. This is because laser rangefinders based on the phase method can easily overcome one of the major drawbacks of ultrasonic rangefinding: the large error, so that the measurement accuracy reaches the millimetre level. The main drawbacks of laser rangefinders based on this method are the complexity of the circuit, the shorter distance (about one hundred metres, after the efforts of many scientists, there are now also phase method laser rangefinders with a distance of several hundred metres).
Phase method laser distance measuring technology, is the use of radio frequency laser, amplitude modulation and sinusoidal modulation of light round-trip rangefinder and the distance between the target produced by the phase difference measurement, according to the modulation of the wavelength and frequency of light, the conversion of the laser time of flight, and then calculate the distance to be measured in turn. The method generally requires the placement of mirrors at the object to be measured, the laser will be reflected back to the laser rangefinder in the original way, by the receiver module of the discriminator to receive processing. In other words, the method is a passive laser ranging technique with co-operative target requirements.
