Map Projection

Shape of the earth that we see is a model of earth made by man, sometimes there is a round sometimes elliptical. But the actual shape of the earth is not like that, the shape is irregular. And to make it easier to describe it, is generally made into a round. And the round shape is transformed into a flat by the map. Map is a picture of the earth's surface in a horizontal plane.

Therefore the earth's surface is not flat (curved-arch does not irregular), but the map takes a picture in a horizontal plane, the necessary conversion from field to field curvature of the earth is actually flat to avoid distortion of the earth's surface.

The size of the earth are as follows:
Ellipticity: 0003 352 9
Mean radius: 6,372.797 km
Equatorial radius: 6,378.137 km
Polar radius: 6,356.752 km
Aspect Ratio: 0996 647 1
The equator radius longer than the polar radius

Do you ever orange peel? Surely it would be difficult to put the orange peel into a flat field with orange skin with all of them connected. As well as experienced by the cartographers when mapping the surface of the earth, they must move the geographical certain way, pull and merge the parts back together for a continued mutually flat map. Map, is no exception globe, is distorted from the actual earth. For smaller areas, no significant distortion due to a small region in the globe looks like a flat surface. For larger areas or for purposes that require high accuracy, however, distortion is very important. Therefore we need a map projection. In the preparation of maps required a projection map which gives the relationship between points on earth with the map, the projection should be selected that has a small distortion.

In principle, the meaning of the projection map is an attempt to change the shape of curved to form a flat surface, with the requirements of the modified form it should remain, the surface area is changed must remain and the distance between one point to another point on the surface are modified must continue.

The projection map is the techniques used to describe a part or the whole surface of three-dimensional spherical to flat two-dimensional surface with minimal distortion. In a projection system that provides map pursued the relationship between the position of the points on the earth and on the map.

To meet all three requirements for a change of the field of arch onto a flat surface it seems highly unlikely, then there are compromises in using these terms, so that came various types of projections. Some common types of projection is a cylinder / tube (cylindrical), cone (conical), flat field (zenithal) and composition (arbitrarry)
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