plane surveying assumes the surface of earth as plane.
plane surveying assumes the surface of earth as plane.
which survey assume the surface of earth as plane?
plane surveying
bullet::::- "topographic survey": a survey that measures the elevation of points on a particular piece of land, and presents them as contour lines on a plot.









































section::::types.:plane and geodetic surveying.









































based on the considerations and true shape of the earth, surveying is broadly classified into two types.









































"plane surveying" assumes the earth is flat. curvature and spheroidal shape of the earth is neglected. in this type of surveying all triangles formed by joining survey lines are considered as plane triangles. it is employed for small survey works where errors due to the earth's shape are too small to matter.
surveying
if the earth were perfectly spherical and radially homogeneous, then the longitude at a point would be equal to the angle between a vertical north–south plane through that point and the plane of the greenwich meridian. everywhere on earth the vertical north–south plane would contain the earth's axis. but the earth is not radially homogeneous and has rugged terrain, which affect gravity and so can shift the vertical plane away from the earth's axis. the vertical north–south plane still intersects the plane of the greenwich meridian at some angle; that angle is the astronomical longitude, calculated from star observations. the longitude shown on maps and gps devices is the angle between the greenwich plane and a not-quite-vertical plane through the point; the not-quite-vertical plane is perpendicular to the surface of the spheroid chosen to approximate the earth's sea-level surface, rather than perpendicular to the sea-level surface itself.
longitude