What kind of light is generally used for refraction ranging?

Gamma rays are usually chosen to measure distance by refraction.

Distance measurement refers to measuring the length of the connecting line between two points on the ground. Usually, what needs to be measured is the horizontal distance, that is, the length of the projection of the connecting line between two points on the horizontal plane. It is one of the elements to determine the plane position of ground points. This is one of the most basic tasks in measurement. Usually, what needs to be measured is the horizontal distance, that is, the length of the projection of the connecting line between two points on the horizontal plane.

Method:

1, measuring distance: directly measure the distance between two points with a measuring ruler.

2. Sight distance measurement: a method of measuring the distance between two points with a measuring instrument with sight distance device according to the principles of optics and trigonometry.

3. Distance measurement by parallax method: use theodolite to measure the horizontal angle of the fixed-length baseline level, and use trigonometric formula to calculate the horizontal distance between the instrument and the baseline.

4. Electromagnetic wave ranging: In the 1940s, electromagnetic wave ranging appeared. Using it to measure distance has the advantages of wide measuring range, high ranging accuracy and high working efficiency, so electromagnetic wave ranging has become an ideal ranging method.

Photoelectric rangefinder, also known as light speed rangefinder, is an instrument that uses modulated light waves for accurate ranging. The range can reach about 2.5 kilometers, and it can also be used for night work. There are many kinds of photoelectric rangefinders, among which infrared rangefinders have developed most rapidly. The principle of photoelectric ranging is: when measuring the distance between two points, place a rangefinder at one point to be measured and a reflector at the other. The rangefinder sends light to the reflector, and returns to the instrument after being reflected by the reflector.