First, we understand the concept of diffuse reflection. Diffuse reflection is a phenomenon in which light projected on a rough surface is reflected in all directions. Let me talk about how the laser rangefinder handles diffuse reflection?

Everyone knows that laser rangefinders measure far away road signs. This is because the surface of the road sign is smooth and reflective, so the measurement effect is good. It's like finding road signs flashing in car lights on a highway, except that the laser light emitted by a laser rangefinder is invisible and the effect is the same.

Secondly, the laser rangefinder is a feasible method to deal with diffuse reflection. The detection device of laser rangefinder (pulse type) generally uses avalanche photodiodes, which are only sensitive to light of specific wavelengths. If the wavelengths match, very small light intensities can be detected, but if the wavelengths are not matched, even if the light intensities are large, they cannot be detected. The laser has the characteristics of good monochromaticity, and the commonly used wavelength is 905nm. Therefore, the received reflected light signal is not easily interfered by light of other wavelengths and intensities in the environment. In addition, it can also increase the laser emission power of the laser rangefinder, but the general laser rangefinder does not have such a function!