Laser ranging is actually an active optical detection method. The detection mechanism of active optical detection is: the detection system emits a beam (in optical detection, generally infrared or visible light) to the target, and the beam is radiated by the target surface to generate an echo signal. The information to be measured is directly or briefly contained in the echo signal. The receiving and signal processing system obtains the measurand by receiving and analyzing the echo signal.

The man-machine operation issues a ranging command, the starting laser emits a laser pulse, and a small part of the energy passes through the beam splitter and is directly sent to the pulse acquisition system as a reference pulse. As the starting point of timing, start the digital ranging timer to start timing: another Part of it is radiated by the refracting prism and directed towards the target. Generally, the front end of the launch is far-reaching optical system, in order to reduce the divergence angle of the outgoing beam, in order to improve the surface density of light energy, increase the working distance, and also reduce the interference of the background and surrounding non-target objects. Part of the laser beam reaching the target is diffusely reflected by the surface back to the rangefinder; after receiving the objective lens and optical filter, it reaches the detector. The main function of the narrow-band optical filter is to make full use of the excellent monochromaticity of the laser and improve the reliability of the system. Noise ratio; the optical detector converts the optical signal into an electrical signal, and then performs signal amplification, filtering and shaping on the electrical signal. The shaped echo signal turns off the time interval processing module to stop timing.