Plane Survey Geodetic Survey The earth surface is considered as a plane surface. The earth surface is considered as a curved surface. The curvature of the earth is ignored. The curvature of the earth is taken into account. The Line joining two stations is considered to be straight. The line joining two stations is considered as a curved line. The angles of the triangles are considered as plane angles. The angles of the triangles are considered to be spherical angles. The triangles formed by any three points is considered as plane. The triangles formed by any three points is considered as Spherical. Carried out for a small area < 250 km2 Carried out for a large area > 250 km2
