Gyroscope: A device for detecting the angular motion of a high-speed rotating body around one or two axes orthogonal to the rotation axis relative to the inertial space. The angular motion detection device made of other principles has the same function, which is also called gyroscope.

　　The principle of gyroscope is that the direction pointed by the rotating shaft of a rotating object will not change when it is not affected by external forces. According to this truth, people use it to keep the direction, and the thing they make is called gyroscope. Gyroscope should give it a force when working, so that it can rotate quickly, which can generally reach hundreds of thousands of revolutions per minute and can work for a long time. Then the direction indicated by the shaft is read by various methods, and the data signal is automatically transmitted to the control system.

　　Gyroscope is mainly used in mobile communication in satellite communication. At present, fiber optic gyroscopes and laser gyroscopes are mainly used in satellite communication.

　　Fiber optic gyroscope is a sensitive element based on optical fiber coil, and the light emitted by laser diode propagates along the optical fiber in two directions. The change of light propagation path determines the angular displacement of the sensitive element. Compared with traditional mechanical gyroscopes, fiber optic gyroscopes have the advantages of full solid state, no rotating parts and friction parts, long service life, large dynamic range, instantaneous start, simple structure, small size and light weight. Compared with the laser gyroscope, the fiber optic gyroscope has no locking problem, and the optical path does not need to be precisely machined in the Shi Ying block, so the cost is low.

　　The principle of laser gyro is to measure the rotational angular velocity by using the optical path difference. In the closed optical path, two beams of light transmitted clockwise and counterclockwise from the same light source interfere with each other, and the rotation angular velocity of the closed optical path can be measured by detecting the change of phase difference or interference fringe.