July 7 13 Blog

Lab 3 Write Up
Working with the preserved map projections of Conformal, Equidistant and Equal Area, has showed me the importance of knowing and setting the proper map projection when given a GIS project. I will discuss the following 3 topics, first how the map projection differed from each other, second the results (distance from Washington DC to Kabul) concluded from each of the map projections. Lastly the preferred map projection I would use for my GIS usage.
The map projections of Conformal, Equidistant and Equal Area have their own way of projecting the earth. The first map made of the conformal projects of WGS 1984 Web Mercator and World Mercator. Both projections keep the distances at the Equator relatively correct, but “stretch” the polar areas. This is also the same property that my Gall Orthographic Projection (Equal Area Map) and Plate Carree Projection (Equidistant Map Projection) have as well. The Equidistant (Conic) Projection on my equidistant projections map shows a view from the North Pole but has better represents the size and shapes of the Greenland and Russia, which the other projections I made did not. The problem with this projection is the any land mass south of the equator is exaggerated, such as Australia, Africa and Madagascar. The Sinusoidal Projection is the only map projection that does not “stretch” or exaggerate like the other projections. It keeps the land masses proportional and a better representation of the earth’s land mass. The only problem is the poles areas where the projection creates a point and is not rounded.
With the varying differences in each projection came different results of the distant between Washington DC to Kabul. Both the conformal projections had the distant of the two cities at about 10,000 miles. The equal area map projections had the distant of the two cities between 7,200 miles and 8,100 miles, my assumption is that the equal area map projections keeps the distances at these latitudes consistent, unlike the conformal projections. The equal distant map projections had different results the Plate Carree projection distance between DC and Kabul is 10,200miles the most of any projection. Compared to the equidistant (conic) projection of 7,800 miles the lowest of the projections. I equidistant (conic) projection is the most correct due to the projection following true shape of the earth from its northern projection.
With so many different results from the measurement of distances of Washington DC and Kabul. I have to come to the conclusion that each map projection serves a different purpose. The proper projection should be used when needed, for example finding places and distances in the North Pole areas as such with equidistant (conic) projection. The projections each do have some error but it is necessary for them to be used as they are serve as a template for what the earth shape is like. I feel however that projections may become obsolete as GPS has allowed the proper measurement of our earth will eventually be the norm and projection become a thing of the past.