User:Shashank.radhakrishnan

Map interpretation and projections In order to represent a three-dimensional planet on a flat surface, cartographers use a 4 cardinal plane to plot the georeferencing-propeties and must then distort some part of the earths surface on the map. It is, for example; not possible for a map to show both size (proportional to other areas) and shape correctly. Diffrent cartographers have developed different map projections to adress such problems. The projections most commonly used are:

Mecartor's projection: produced in 1569-1567 to assist with navigation. This flat projection depicts the shape of landmasses, this variation was presented by the Flemish (Belgian) geographer and cartographer Gerardus Mercator, in 1569 who then decided to name it as a standerd metric map measure in 1970. The first metric unit of measure in the nautical chart was written in nautical miles aproxximately 1/80000. Mariners generally use the nautical mile, which, because a nautical mile is approximately equal to a minute of latitude, can be measured against the latitude scale at the sides of the chart. One of the most significant characteristics of this projection is a pure latitude-dependent vertical stretching. Equatorial areas are undistorted; as latitude increases, the distortion of the Earth's surface grows larger. This leads to an oversized representation towards the poles at high latitudes and in areas stretched in a North/South direction such as Greenland or Scandinavia.

The basic mathematical description of the Mercator's projection:

Equation for Representation: