Plans and Maps

Objective of surveying

To collect field data
To prepare plan or map of the area surveyed;
To analyse and to calculate the field parameters for setting out operation of actual engineering works.
To set out field parameters at the site for further engineering works

Plan : Orthographic representation of features on or near the surface of the earth in Large Scale on a horizontal plane.
The horizontal plane is represented by the plane of the drawing sheet on which the plan is drawn to some scale.
However, the surface of the earth is curved it cannot be truly represented on a plane without distortion.
In plane surveying the areas involved are small, the earth's surface may be considered as a plane and hence plane is constructed by orthographic projection.
A plan is drawn on a relatively large scale.

Graphical representation of features on or near the surface of the earth in small scale on a horizontal plane and is constructed using a projection system other than orthographic.
On a plan generally, only horizontal distances and directions or angles are shown on a topographic map. however, the vertical distances (elevations) are also represented by contour lines.