The laser range finder is an instrument which uses the laser to measure the distance of the target accurately. Laser range finder at work to shoot a bunch of very fine laser, by photoelectric element receives the reflected laser beam timer determination laser beam from the launch to receive the time, calculate the distance from the observer to the target.

若激光是连续发射的，测程可达40公里左右，并可昼夜进行作业。若激光是脉冲发射的，一般绝对精度较低，但用于远距离测量，可以达到很好的相对精度。

If the laser is continuous emission, the measurement process can be up to 40 kilometers, and can work day and night. If the laser is a pulse emission, the general absolute accuracy is low, but for long distance measurement, it can achieve a good relative accuracy.

世界上第一台激光器，是由美国休斯飞机公司的科学家梅曼于1960年，首先研制成功的。美国军方很快就在此基础上开展了对军用激光装置的研究。1961年，第一台军用激光 测距仪通过了美国军方论证试验，对此后激光测距仪很快就进入了实用联合体。

The world's first laser, by the Hughes Aircraft Co of the United States Maiman in 1960, the first successful development. On the basis of the rapid development of the military laser equipment. In 1961, the first military laser range finder was tested by the US military, and the laser range finder soon became a practical utility.

由于激光测距仪价格不断下调，工业上也逐渐开始使用激光测距仪。国内外出现了一批新型的具有测距快、体积小、性能可靠等优点的微型测距仪，可以广泛应用于工业测控、矿山、港口等领域。

Since the laser range finder prices continue to decline, the industry has gradually began to use the laser range finder. At home and abroad, a new type of micro range finder, which has many advantages such as fast ranging, small size, reliable performance, can be widely used in industrial control, mining, port and other fields.

激光是六十年代发展起来的一项新技术。它是一种颜色很纯、能量高度集中、方向性很好的光。激光测距仪是利用激光进行测距的一种仪器。它的作用原理很简单：通过测定激光开始发射到激光从目标反射回来的时间来测定距离。例如用激光测距仪来测量月球的距离，如果激光从开始发射到从月球反射回来的时间被测定为2.56秒，激光发射到月球的单程时间就等于1.28秒，而激光的速度是光速，等于每秒三十万公里。因此，测得的月球离地球的距离为单程时间和光速的乘积，即三十八万四千公里。为了发射和接收激光，并进行计时，激光测距仪由激光发射器、接收器、钟频振荡器及距离计数器等组成。

Laser is a new technology developed in the sixty's.. It is a very pure color, energy is highly concentrated, the direction of a very good light. Laser range finder is a kind of instrument that uses laser to measure distance. Its principle is very simple: the determination of distance by measuring the time that the laser begins to be emitted to the laser to reflect back from the target. For example with a laser range finder to measure the moon's distance, if the laser from the beginning of the emission to come back from the moon reflection time were determined for 2.56 seconds laser transmitter to the moon one-way time is equal to 1.28 seconds, while the laser speed is the speed of light, is equal to one per second three hundred thousand kilometers. As a result, the distance between the moon and the earth is the product of one way time and the speed of light, that is, three hundred and eighty-four thousand kilometers. In order to transmit and receive the laser, and timing, laser range finder by the laser transmitter, receiver, clock oscillator and distance counter, etc..

激光测距仪还能用来对人造卫星跟踪测距，测量飞机飞行高度，对目标进行瞄准测距，以及进行地形测绘，勘察等。

Laser range finder can also be used for satellite tracking and ranging, measuring the altitude of the aircraft, aiming at the target, as well as surveying and mapping, surveying and so on.