How do planes and ships navigate?

An important factor in navigation is to know your position accurately. Ships in the ocean are affected by waves and wind direction, and aircraft in flight are affected by airflow. After sailing for a period of time, it is difficult to determine your position. On the ship, there is a way to determine your latitude and longitude by measuring the constellations on a clear night. This method is called "astronomical navigation". Some also use radio waves for navigation. This method is to send out radio waves from the destination. Directional antennas installed on ships or airplanes can automatically aim at the direction of radio waves. With this navigation method, a ship or plane can sail in the direction of radio waves, regardless of its position, and finally reach its destination. For the long-distance routes of aircraft, there are often several "navigation points" in the middle. The plane first flies to the first navigation point by radio navigation, then turns to the second point frequency, is guided to the second point, and so on, and finally reaches the destination.

A relatively perfect navigation method is to distribute several ground stations on the ground and send out radio waves. According to the direction of radio waves received from each station, the plane can display its exact position with automatic equipment. To do this, it is necessary to establish a ground station on the ground in a planned way to form a navigation system. For areas with frequent flights, this is a common method at present.

However, this method is difficult to use in underdeveloped areas, or in the vast ocean, the ground station has not been established or it is difficult to establish. At present, due to the development of space technology, the technology of multiple fixed-point satellite navigation has been established, which is called "satellite navigation". Satellites have a large coverage of radio waves and can be used for global navigation. In this way, planes or ships equipped with satellite navigation equipment will never know where they are, and there is no need to stick their heads out of the plane and yell at fishermen like Lindbergh.

It can be seen that the development of navigation technology in recent decades is centered on how to facilitate traffic. It makes people's long journey on the whole earth as familiar as at home.