What is Surveying?
Performing surveys is the art of figuring out where things are in relation to one another. A variety of surveying equipment is used to properly measure horizontal lengths, vertical distances (elevations), horizontal angles, and vertical angles to determine the relative positions of the objects. In this article, we will briefly discuss the difference between plane surveying vs geodetic surveying.
What is Levelling?
Surveying’s levelling branch deals with determining the relative positions of points on the earth’s surface in a horizontal plane. As a result, levelling is concerned with taking measurements in the vertical direction. Surveying is concerned with taking measurements on a flat surface.
Purposes Of Surveying
The objectives of surveying are,
1. To take measurements to ascertain the relative locations of the points, above or below the surface of the ground.
2. To measure the areas and volumes.
3. To layout or to mark the positions of the proposed structures on the ground, e.g. building, canal, road, rail, highway, etc.
3. To develop a map or a plan to show the relative location of the objects on the surface of the earth.
4. To fix the boundaries of districts, states, and countries.
Uses Of Surveying
Various uses of surveying are,
1. To create a topographical map of a country that depicts natural features such as rivers, streams, lakes, hills, valleys, forests, and so on.
2. To create a cadastral map that depicts the boundaries of fields, plots, and so on.
3. To create a contour map of the area in order to determine the best potential location for the dam, canal, buildings, roads, railways, bridges, and so on.
4. Route surveys are carried out on the ground to determine the alignment of a road, railway, canal, electric tower line, tunnel, bridge, and so on.
5. To draw on paper the uneven boundaries of plots and existing constructions.
6. To construct a specific gradient or slope for water supply, drainage, a gas line, or a road.
7. To conduct a survey of lakes, rivers, and the sea in order to examine the bed profile.
8. To determine the level diﬀerence between diﬀerent spots on the ground surface.
9. Military surveys are performed to determine strategic points of interest.
10. Mine surveys are performed to discover mineral resources.
11. A city survey is used to develop streets, water supply systems, and sewers, among other things.
12. Remote sensing can be used to determine agricultural soils, forest cover, and water bodies, among other things.
Plane Surveying Vs Geodetic Surveying
What Is Plane Surveying?
It is a method of surveying in which the earth’s mean surface is treated as a plane and the spheroidal shape is ignored. It is appropriate for relatively small areas, i.e. less than 250 km2. It can be used for engineering, architecture, commercial, scientific, and other reasons.
What Is Geodetic Surveying?
Specifically, it refers to a method of surveying where the spherical shape of the earth is taken into consideration. It is used for large-scale surveying projects that require extensive coverage. Obtaining accurate maps of large areas and establishing control points for all other surveys are two applications of this technique.
Diﬀerence Between Plane Surveying Vs Geodetic Surveying
Plane Surveying Vs Geodetic Surveying
|It is the type of surveying in which the mean surface of the earth is considered as a plane and the spheroidal shape is neglected.
|It is the type of surveying in which the spheroidal shape of the earth is taken into account.
|All survey lines are considered as straight and all triangles are considered as plane triangles.
|All survey lines are considered curved and all triangles are considered as spherical triangles.
|It is used for the survey of relatively small areas, i.e. less than 250km2.
|It is used for large areas, i.e. more than 250km2.
|The standard of accuracy is low.
|The stranded of accuracy is high.
|The directions of plumb lines at various points are assumed to be parallel to one another.
|There are no parallels between the directions of plumb lines at various points along the line of sight.
|It is useful for engineering, architectural, commercial, scientific, etc. purposes.
|In order to obtain accurate maps of large areas and to set control points for all other surveys, it is necessary to employ this technique.
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