## Map Projections## All you need to knowIf you are primarily interested in buying a map for decor purposes then the main thing to know is that a map projection determines the shape of the map. For example item # 4101-1_01 is a map of the whole world using our
## Brief explanationFor purposes of explaining projections further we will consider the world to be sphere (it is in fact not a perfect sphere but rather a spheroid) and maps are flat. A map projection is a means of “projecting” the spherical map of the world, or part of it, on to a flat surface. It is impossible to do this without introducing distortion, sometimes very significant distortion. Consider trying to wrap cellophane around an orange without a wrinkle. Some distortions of conformality, distance, direction, scale and area always result. On very large scale maps (i.e. maps covering small areas) many of these distortions are imperceptible to the eye and therefore insignificant. On the other hand, they are completely obvious on small scale maps like maps of the whole world. ## Practical examplesIf you planned on sailing from Lisbon to the Havana you would probably need to know the distance and the direction. If you drew a straight line from one to the other, on most maps it would NOT be the shortest route. You could choose an Azimuthal Equidistant projection centered on one of those two locations. Distances and direction to any point from the projection center would be correct. Unfortunately, no map projection can show true distance between ## Interesting applicationsAt Newport Geographic we try to make our maps useful and educational but above all we want them to be interesting. To that end we have developed some completely unique maps. Consider our PolyView map series, for example item # 41BH-1-2_04 . It is made up of 32 separate polygons (20 hexagons and 12 pentagons) that together represent the whole world. Each polygon is a separate map in Gnomonic projection. A straight line between any two points that stays on a polygon is a great circle and so represents the shortest distance between those two points. Any such line that crosses polygons but remains within the map will approximate a great circle. Since the area covered by each polygon is relatively small distortion across the entire map is minimal. The result is a flat map that can give the shortest route between two points with very little error in distance, scale and area. |