Navigation and longitude latitude
At present, the landmark location, the traditional astronomical positioning method has become a supplementary means of special circumstances, the radio navigation method after radio direction finder (1921), radar (1935), Roland A (1943), Decca (1944), Roland C (1958), satellite navigation system (1964), global the positioning system (1993) the development process of high precision satellite navigation era.
The direction of the East and West, which is gradually shortened from the equator to the north and south polesThe equator to the Antarctic latitude, equatorial North latitude.
A line connecting the poles of the north and south, indicating the direction of the north and South; a half circleFrom the longitude of 0 degrees east longitude, West to the west;
