The data collected through field surveying are presented in the form of a plan or a map.

Since, the actual surface of the earth is curved, and the surface of the map is flat, a method of projection is usually used to fit a curved surface of earth into a plane surface of paper. However, no map can represent a terrain without some distortion. To minimise the effect of distortion, conformal projections are generally employed.

To prepare a map, first a grid of meridians and parallels of latitude is being prepared to provide a framework of map. Control points are then plotted by their spherical coordinates (latitude, longitude). A plane coordinate system is then used to plot other points accurately in orthogonal coordinate system obviating direct use of spherical coordinates.

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