Mercator Map ProjectionMercator - introduced in 1569 by Gerardus Mercator. It is often described as a cylindrical projection, but it must be derived mathematically. The meridians are equally spaced, parallel vertical lines, and the parallels of latitude are parallel, horizontal straight lines, spaced farther and farther apart as their distance from the Equator increases. This projection is widely used for navigation charts, because any straight line on a Mercator-projection map is a line of constant true bearing that enables a navigator to plot a straight-line course. It is less practical for world maps because the scale is distorted; areas farther away from the equator appear disproportionately large. On a Mercator projection, for example, the landmass of Greenland appears to be greater than that of the continent of South America; in actual area, Greenland is smaller than the Arabian Peninsula.
Miller Cylindrical Map ProjectionMiller Cylindrical - a modified Mercator projection, proposed by Osborn Maitland Miller (1897-1979) in 1942. The parallels of latitude are scaled by a factor of 0.8, projected according to Mercator, and then the result is divided by 0.8 to retain scale along the equator.
Mollweide Map ProjectionThe Mollweide projection is a pseudocylindrical map projection generally used for global maps of the world (or sky). Also known as the Babinet projection, homolographic projection, or elliptical projection. As its more explicit name Mollweide equal area projection indicates, it sacrifices fidelity to angle and shape in favor of accurate depiction of area. It is used primarily where accurate representation of area takes precedence over shape, for instance small maps depicting global distributions.
Orthographic Map ProjectionOrthographic - a perspective (or azimuthal) projection, in which the sphere is projected onto a tangent plane. It depicts a hemisphere of the globe as it appears from outer space. The shapes and areas are distorted, particularly near the edges, but distances are preserved along parallels.
Robinson Map ProjectionRobinson - made in 1988 to show the entire world at once. It was specifically created in an attempt to find the good compromise to the problem of readily showing the whole globe as a flat image. The projection is neither equal-area nor conformal, abandoning both for a compromise. The creator felt this produced a better overall view than could be achieved by adhering to either. The meridians curve gently, avoiding extremes, but thereby stretch the poles into long lines instead of leaving them as points. Hence distortion close to the poles is severe but quickly declines to moderate levels moving away from them. The straight parallels imply severe angular distortion at the high latitudes toward the outer edges of the map, a fault inherent in any pseudocylindrical projection.
Stereographic Map ProjectionStereographic - it is a particular mapping (function) that projects a sphere onto a plane. The fact that no map from the sphere to the plane can accurately represent both angles (and thus shapes) and areas is the fundamental problem of cartography. In general, area-preserving map projections are preferred for statistical applications, because they behave well with respect to integration, while angle-preserving (conformal) map projections are preferred for navigation. The stereographic projection falls into the second category.
Van der Grinten Map ProjectionVan der Grinten - neither equal-area nor conformal projection. It projects the entire Earth into a circle, though the polar regions are subject to extreme distortion. The projection offers pleasant balance of shape and scale distortion. Boundary is a circle; all parallels and meridians are circular arcs (spacing of parallels is arbitrary). No distortion along the standard parallel at the equator.
Wagner VI Map ProjectionWagner VI - a pseudocylindrical whole Earth map projection. Like the Robinson projection, it is a compromise projection, not having any special attributes other than a pleasing, low distortion appearance.
Winkel Tripel Map ProjectionWinkel Tripel - a modified azimuthal map projection proposed by Oswald Winkel in 1921. The projection is the arithmetic mean of the equirectangular projection and the Aitoff projection. Goldberg & Gott show that the Winkel Tripel is arguably the best overall whole-earth map projection known, producing very small distance errors, small combinations of ellipticity and area errors, and the smallest skewness of any map. In 1998, the Winkel Tripel projection replaced the Robinson projection as the standard projection for world maps made by the National Geographic Society.
