Cartography and the three different ways of making maps cylindrical projection conic projection and

Selecting a model for a shape of the Earth involves choosing between the advantages and disadvantages of a sphere versus an ellipsoid.

cylindrical map projection

The scale of orthographic projection is most accurate at the tangent area. The general pattern of distortion is radial. This is a good projection for uses like plotting airline connections from one airport to all others.

Conic map projection

It is best suited for maps of continents or regions that are equally extended in all directions from the centre, such as Asia and the Pacific ocean. Moving the developable surface away from contact with the globe never preserves or optimizes metric properties, so that possibility is not discussed further here. Which developable surface to use for a projection depends on what region is to be mapped, its geographical extent, and the geometric properties that areas, boundaries, and routes need to have, given the purpose of the map. Map projections with a equal-area distortion property on the other hand, represent areas correctly, but as the region becomes larger, it shows considerable distortions of angles and consequently shapes figure below. This is called the aspect of a map projection. Meridians are straight lines and equally spaced, while parallels are also straight lines but their spacing increases as they get closer to the poles. For example J.

Print Latitude and longitude coordinates specify positions in a spherical grid called the graticule that approximates the more-or-less spherical Earth.

Depending on the map projection you choose, some projections may cause distance between features on a map to be preserved while distortion is introduced to shape. Suppose the same point, located at 60oN and oW, is projected on a map that uses the stereographic projection where the reference surface is a sphere with a radius of m.

The mapping of meridians to vertical lines can be visualized by imagining a cylinder whose axis coincides with the Earth's axis of rotation. The projection was originally designed to display accurate compass bearings for sea travel.

Transformation of geographic coordinates longitude and latitude to Cartesian x,y or polar plane coordinates. All great circles - the shortest routes between points on a sphere - are shown as straight lines on the gnomonic projection.

Whereas equal-area projections distort shapes while preserving fidelity of sizes, conformal projections distort sizes in the process of preserving shapes.

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Types of Map Projections