The gyrocompass is an inertial device that does not depend on any external information such as sound, light, electricity, or magnetism to autonomously search for true north and establish a stable true north position reference on the moving object to accurately determine the moving direction of the moving object. The gyrocompass uses the combined effect of the earth's rotation angular velocity and the gravity field to make the rotation axis of the two-degree-of-freedom gyroscope automatically search for true north. The datum can also provide azimuth datum for artillery, torpedoes, missiles, etc.
For a long time, the magnetic compass has been widely used on various ships as a pointing instrument for determining the ship's position. However, with the development of nautical business and shipbuilding technology, steel ships have replaced wooden ships, especially the emergence of large and medium-sized ships and submarines. The reliability and accuracy of magnetic compasses are far from meeting the requirements, which prompted people to seek new directions Instruments, soon the gyrocompass came out.
The gyrocompass, as a navigation instrument that can accurately find the true north, has been widely used on ships, has become the main instrument for maritime navigation, and is regarded as the pioneer of modern inertial navigation.