How to ensure the precision of laser rangefinder?
Today, laser range finders of a wide range of functions, but from the operation mode (or operation principle) can be seen only two, namely: pulse laser ranging and continuous wave laser ranging.The principles and characteristics of the two rangefinders are described below:
The principle of pulsed laser ranging is that a series of very narrow light pulses (pulse width is less than 50ns) are transmitted to the policy by pulsed laser, the light reaches the policy surface and is partially reflected, and the interval between the rangefinder and the policy can be calculated by measuring the moment when the light pulse is transmitted to the receiver. Assuming the measured interval is h, the reciprocating moment of light pulse is t, and the propagation velocity of light in the air is c, then: h=ct/2
Pulsed laser rangefinders emit very strong lasers.The range finding ability is strong, even for non-cooperative policy, the maximum range can reach more than 30000m.Its ranging accuracy is generally 5 meters, the highest up to 0.15m.Pulsed laser rangefinders can be used for ranging from military to non-cooperative ranges, to climate measurements of visibility and cloud heights, and to fine interval measurements of satellites.
Successive wave laser rangefinder usually adopt ranging based on the phase method and its principle is to approach first launched a beam of laser beam through modulation of successive waves, after arriving at the policy on the surface of the beam is reflected, after the launch of the modulation measurement of the phase difference between the laser beam with the receiver to receive the echo can be concluded that policy and the gap between the rangefinder.