A laser rangefinder is an instrument that uses a laser to accurately measure the distance to a target. The laser rangefinder emits a very thin laser beam to the target when it is working, and the photoelectric element receives the laser beam reflected by the target. The timer measures the time from the emission to the reception of the laser beam, and calculates the distance from the observer to the target.

If the laser is fired continuously, the measuring range can reach about 40 kilometers, and the operation can be carried out day and night. If the laser is pulsed, the absolute accuracy is generally low, but for long-distance measurement, a good relative accuracy can be achieved.

The world's first laser was first developed in 1960 by the American Hughes Aircraft Company scientist Maiman. The U.S. military soon carried out research on military laser devices on this basis. In 1961, the first military laser rangefinder passed the demonstration test of the US military, after which the laser rangefinder soon entered the practical consortium.

The laser rangefinder is light in weight, small in size, simple in operation, fast and accurate, and its error is only one-fifth to several hundredths of other optical rangefinders, so it is widely used in terrain measurement, battlefield measurement, tank measurement, etc. , ranging from aircraft, ships and artillery to targets, measuring the height of clouds, aircraft, missiles and artificial satellites, etc. It is an important technical equipment to improve the accuracy of high tanks, aircraft, ships and artillery.

As the price of laser rangefinders continues to drop, the industry has gradually begun to use laser rangefinders. A number of new miniature rangefinders have appeared at home and abroad with the advantages of fast ranging, small size and reliable performance, which can be widely used in industrial measurement and control, mines, ports and other fields.