# 2 Major Classification Of Surveying And Differences

Surveying is classified primarily into:
1. Geodetic Surveying
2. Plane Surveying
1. Geodetic Surveying
Geodetic Surveys are surveys, which take into account the true shape of the earth. Geodetic surveys are typically carried out with great precision, often over long distances, and are used not only to determine the size, shape and gravity field of the earth.
Geodetic surveying is a process of surveying by considering the curvature or spherical shape of the earth. The exact positions of points obtained on plane surveying are given by geodetic. In geodetic surveying the curvature of the earth is taken consideration, that is, the knowledge of spherical geometry is necessary.
2. Plane Surveying
Plane surveying is the process of surveying by assuming that the earth is flat. Which mean the curvature or spherical shape of the earth is not considered in plane surveying calculations.
Plane surveys are the most commonly practiced method of surveying and treat the earth as a flat or “plane” surface. Good enough for small-scale surveys in limited areas, the curvature of the earth has no effect on the results, thus the computations and results can be referenced to a plane or flat surface.
In plane surveying the area under survey is taken to be a horizontal plane and the measurement plotted will represent the projection on the horizontal plane of the actual file measurements.
Differences Between Geodetic And Plane Surveying
1. In Geodetic Surveying: The curvature of earth is considered.
In Plane Surveying: Curvature of the earth is not taken in to consideration.
2. In Geodetic surveying, line joining two points of triangle formed by three points is considered as curved line of spherical triangle and angles of triangle are considered as spherical angles.
In plane surveying, line joining any two points of triangle formed by any three points is considered as straight line and plane triangle are assumed to be plane angles.
3. In Geodetic Surveying: The survey is done on large area greater than 250 km2.
In Plane Surveying: The survey is done on smaller area less than 250km2.
4. In Geodetic Surveying: High accuracy is required.
In Plane Surveying: The required accuracy is competitively low.
5. In Geodetic Surveying: Very refined methods and instruments are used.
In Plane Surveying: Simple methods and instruments can be used as the required accuracy is low.
6. In Geodetic, it is done by the government department while in Plane is done by individual.
Uses Of Plane Surveying
The uses of plane surveying include:
1. The measurement of areas.
2. The making of plans in connection with legal document (including land transfer), Parliamentary bill etc.
3. The making of plane connection with the work of the civil engineer, architect, builder, structural engineer and two planners.
4. The making of planes and map for military, geographical and geological and other purposes.