How does the plane navigate?

The earliest old aircraft relied on the pilot's visual navigation, that is, when the pilot was flying in the sky, he looked at the map in his hand and looked for landmarks. There is also compass navigation: on bombers and passenger planes, special navigators can use speed-direction to calculate the orientation of the plane. Of course, this method requires that the plane can only fly in a straight line. The navigator should constantly read the data of the speed and direction of the aircraft and mark them on the navigation map, and add visual correction of landmarks to be more accurate.

During World War II, radio navigation was developed, that is, multiple radio signal stations were set on the ground, and there was a radio compass on the plane, which could directly read the position of the radio transmitter. As long as the specific positions of the two radio stations and the reading direction of the radio compass are known, the position of the plane can be obtained by triangulation on the map. Before GPS appeared, it was always the main way of car navigation.

During civil aviation or the Cold War, the Chinese and Russian air forces used ground navigation, that is, ground radar to track aircraft. Radar can accurately measure the direction distance of the aircraft, directly know the position of the aircraft on the map, and tell the pilot through ground command.

The best navigation now is GPS. In fact, the principle is the same as that of radio navigation, but the degree of automation is higher. But radio navigation and ground radar navigation are still indispensable.