What are all the technical principles of laser rangefinders?
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 meters, can more easily reach the millimeter 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 realization 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 ranging: the large error, so that the measurement accuracy reaches the millimeter level. The main disadvantage of laser rangefinders based on this method is the complexity of the circuit, the shorter distance (about one hundred meters, after the efforts of many scientists, there are now also a few hundred meters of the action of the phase method of laser rangefinders).
Phase method laser distance measurement 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 original path of the laser light is reflected back to the laser rangefinder, which is received and processed by the discriminator of the receiving module. In other words, the method is a passive laser ranging technique with cooperative target requirements.
