Geodetic latitude and longitude are the general names of geodetic longitude and geodetic latitude. The surface of the earth is an irregular surface. For mathematical representation, suppose it is a rotating ellipsoid with the size and oblateness closest to the earth, which is called the earth ellipsoid. The plane passing through the center of the earth ellipsoid and perpendicular to its axis of rotation is called the ellipsoid equatorial plane, and the straight line intersecting the earth surface is called the equator. The plane passing through the ground point A and the axis of rotation of the earth ellipsoid is called the geodetic meridian plane at point A, and the included angle L between the geodetic meridian plane at point A and the initial geodetic meridian plane (initial meridian plane) is called the geodetic longitude. The included angle b between the normal of the earth's ellipsoid passing through point A and the equatorial plane is called geodetic latitude.

The long latitude of astronomy refers to the latitude and longitude based on the vertical line of a point on the ground and the earth's rotation axis. The plane containing the vertical line of a point on the ground and the earth's rotation axis is called the astronomical meridian plane of point A, the angle λ between this meridian plane and the original meridian plane is called the astronomical longitude of point A, and the angle φ between the vertical line of point A and the equatorial plane of the earth is called the astronomical latitude of point A. ..

Geocentric longitude and latitude are the general names of geocentric longitude and geocentric latitude. The plane containing the connecting line between the geocentric point on the ground and the earth's rotation axis is called the geocentric meridian plane. The angle between the geocentric meridian plane and the original meridian plane at point A is called geocentric longitude; The angle between the connecting line between point A and the center of the earth and the equatorial plane of the earth is called geocentric latitude.