In order to transform conveniently the directional angle of a geodesic line into the geodetic azimuth,the solution of the meridianal convergence is expressed by geodesic coordinates of this point.

• 该解式直接采用该点的测地坐标来求解子午线收敛角；从而能方便地将测地坐标系中任一大地线的方向角转换为大地方位角.