说明：  坐标转换的文档，内部附流程说明，几种转换的方法
(reference ellipsoid, and thus there will be a different geodetic coordinate system; the same country or region in different historical periods, for some reason changed the reference ellipsoid, there will be different geodetic coordinate system. China is currently used mainly three types of geodetic coordinate system, according to the selected reference coordinate origin can be divided into the heart coordinate system, geocentric coordinate system, independent local coordinate system. Each of these three types of coordinate systems and the use of a particular target range, and only through a detailed understanding of the ellipsoidal coordinate system parameters, characteristics and applications, each turn of their mathematical model of ch)