Lab#5

Distance from Washington D.C., USA to Kabul, Afghanistan (in miles):
World Cylindrical projection: 10,099.35 miles
Mollweide projection: 10,155.94 miles
Equidistant Conic projection: 7,927.93 miles
Equidistant Cylindrical projection: 7,003.47 miles
Mercator projection: 10,160.03 miles
Gall Stereographic projection: 7,141.80 miles

Map projections are inevitable in the process of map making. Different projections allow maps to be represented on different planes. All map projections are distorted in some way, but depending on what they are being used for, some distortions are acceptable because they do not interfere with the information being collected, while using the same map for a different reason may make that map unacceptable.

Maps are made to preserve one or more of the following properties: shape, area, bearing, distance, scale, and direction. No map can preserve all of these properties, which is why many different projections are useful.

Different types of projections preserve different types of data. Conformal projections preserve local distance, Equidistant preserves distance, Equal Area preserves area. These projections vary in uses displaying different types of information accurately. One would have to research what type of information they want preserved and use the appropriate map to avoid incorrect information and discrepancies.

An example of discrepancies between maps can be shown by the differences in the distance of Washington D.C. and Kabul in the map projections. They vary from lengths as far as 3,000 miles in some comparisons.