Measurement principle and method of laser rangefinder
What is the principle of using infrared or laser ranging?
The principle of distance measurement can be summarized as measuring the time required for light to travel back and forth to the target, and then calculating the distance D through the speed of light c=299792458m/s and atmospheric refractive index n. Due to the difficulty of directly measuring time, it is usually to measure the phase of continuous waves, which is called a phase measuring distance meter. Of course, there are also pulse type rangefinders, typically WILD's DI-3000
It should be noted that phase measurement is not about measuring the phase of infrared or laser, but rather measuring the signal phase modulated on infrared or laser. There is a handheld laser rangefinder used in the construction industry for measuring houses, and its working principle is the same.
2. Does the plane of the tested object have to be perpendicular to the light?
Usually, precision distance measurement requires the cooperation of a total reflection prism, and the distance measuring instrument used for house measurement directly reflects the measurement from a smooth wall surface, mainly because the distance is relatively close and the signal strength reflected back by the light is large enough. From this, it can be seen that it must be vertical, otherwise the return signal is too weak to obtain the * * distance.
3. Is it possible if the plane of the tested object is diffuse reflection?
Usually, it is also possible to use thin plastic sheets as reflective surfaces in practical engineering to solve the problem of severe diffuse reflection.
4. Ultrasonic ranging accuracy is relatively low and is rarely used nowadays.
Main classification
One dimensional laser rangefinder for distance measurement and positioning;
A two-dimensional laser rangefinder is used in fields such as contour measurement, positioning, and area monitoring;
The 3D Laser Rangefinder is used in fields such as 3D contour measurement and 3D spatial positioning.
