Three Named Map Projections Assignment Example | Topics and Well Written Essays - 1250 words

Three Named Map Projections - Assignment Example In other words, a map highlights the relationship presents between different elements, such as objects and regions, present in the area that it represents. A map can also be defined as a representation of whole or a portion of Earth on a levelled surface to a specific scale. Maps gained their utility from the fact that they were much easier to carry, utilize as well as store then globes, and significantly eased the development of representation on different scales that were both larger and smaller than those possible on globes (Government of Minitoba, 2011). However, while maps allowed for such enhancement, they also introduced several complexities in the art of map drawing (cartography). One of the major problems that were faced by cartographers was the accurate representation of an ellipsoid object on a flat mapping surface. As a result of research on this topic, map projections were introduced. Map projections are methods which are used to represent whole or part of a sphere or a three-dimensional body on to a planar surface (Riesterer, 2008). In terms of earth mapping, map projections were initially used to transfer the features of a globe , such as coordinates and outlines of land areas on to a piece of map. Initially, light was used to "project" a wire globe onto a flat surface, however, as the research progressed these methods were replaced with more scientific method involving mathematical equations and use of computers (Government of Minitoba, 2011). There are basically three major types of projections, cylindrical, planar and conic which are based on the shape of the flat surface (usually paper) on to which the sphere is projected. A cylindrical projection is one in which lines of longitudes are mapped to equidistant vertical lines while rings of latitude are mapped on to horizontal lines. In a planar projection, the directions from the central point are preserved, and great circles through the central points are shown by straight lines on the map. In the conical projection, the lines of longitudes are projected on to a conical surface joining at the apex of the cone. The lines of latitudes are drawn on the cone as rings. This cone is then cut along any longitude line to obtain the conical projection (Riesterer, 2008). All subsequent developments of map project use these three map projections as their basis. An aspect which is considering during the projection process is the aspect of the shape. The aspect of the map describes how the surface is oriented in relation to the sphere or globe. The surface can be normal, transverse or oblique or can also be tangent or secant to the globe. A projection may also be affected by the approximation that is used to measure the shape of the Earth. Some map projection use the approximation of Earth as a sphere, even though Earth is actually and ellipsoid. The use of sphere vs. ellipsoid for Earth approximation is decided by quantifying the advantages and disadvantages of each approximation me thod. Though a more accurate model of Earth, called geoid, exists however it is no used in mapping due to the significant amount of complexities involved in its use (Government of Minitoba, 2011). Despite the fact that more and more accurate methods are being developed as the research in the field of cartography has progressed, it is important to understand that a globe is the only true representation of the Earth's sphere and all attempts made to project it on to a flat surface introduce some sort of distortion in one way or the other. This distortion can be understood from the example of peeling of an orange. Any attempt made to straighten the peel will result in creation of tear and wrinkles on the surface of the peel creating distortion