What is the principle of periscope?

Periscope picture reference: upload.wikimedia/ * * */Mons/Thumb /6/68/ Periscope _ simple.svg/250px-periscope _ simple.svg is the law of reflection. The law of reflection means that when light strikes an interface, its incident light and reflected light form the same angle. Light will be reflected and refracted when it is incident on the interface of different media. When reflecting, the following happens: the reflected line is in the same plane as the incident light and the normal. The reflected line and the incident line are separated on both sides of the normal line, and the included angle with the interface normal line (called incident angle and reflection angle respectively) is equal. The reflection angle is equal to the incident angle. Image reference: upload.wikimedia/ * * */Mons/Thumb/11reflection _ angles.svg/170px-reflection _ angles.svg.

Periscope periscope uses the principle of optical mirror refraction to install lenses at both ends of a long tube. The upper lens will refract the facing image downward, and the bottom lens will refract the refracted image for the second time. The observer can see the image through the bottom refracting mirror in the direction aligned with the upper mirror. Through this device, the personnel inside the submarine can actually observe the surrounding environment with the naked eye. In combat, periscope is also an important means to identify target types and enemies. Periscope usually provides two magnifications, one is small in magnification but large in field of view, which is suitable for searching the surrounding waters quickly, and the other is large in magnification, which provides submarines with the ability to identify and judge the target movement. Modern periscope not only provides better observation effect, but also enhances the observation ability in bad day and night. With the help of ordinary optical cameras, infrared cameras or low-light-level television cameras, the submarine's flexibility in operating periscope is far better than before. After the recorded images are stored in electronic signals, they can also be analyzed afterwards to obtain information. A big challenge of modern periscope design is the improvement of operation speed. Because of the need to run at high speed and keep the image stable, companies have overcome the problems such as vibration caused by high speed in different ways. A common design is to increase the size of periscope to improve its vibration absorption ability.

The principle of light reflection is to reflect through two mirrors.