Map Projections

Different projections of maps are used for different things so picking the right map projection to use really depends on what your map is intended for or intended to do or show. Every map projection has its potentials and limitations. Some ways to determine preciseness and factors that play into picking a good map are showing the correct distance between locations, showing directions, showing the correct shape of the earth or the place you are looking at compared to real life, area and proportions are accurate and seeing how little the map is distorted. But really, it depends on what the purpose of the map is for in order to pick the right projection that fits.

A type of projection is equal area projection. As the name suggests, it is a map that shows all the places in an equal ration area and places are proportional to each other. Because it is it is proportional, it lets us know how big or small a place is relative to another. The Hammer and Craster map preserve the real relationship of size between one place and another. The Craster map does not have any distortions at latitudes 36°46' N. and S. at the central meridian. Thus if someone wanted to focus on the central meridian or this latitude, they would pick the Craster map because it doesn’t distort. The Hammer and Craster map can be good for thematic maps because since areas are proportional, when giving information about a population, someone can compare the population to the size of the place.

The Azimuthal and Equidistant Conic map projections are considered equal distant projections. Equidistant map projections show correct scale between points on the map or along every meridian. For the Azimuthal map, distances are correct between points along straight lines. On the map it shows that the distance between Washington DC and Kabul, Afghanistan is 13,413,685 meters which is the actual distance because they are equidistant maps. Compared to equal area maps such as Hammer that said the distance was 13,398,532 meters and Craster that said 13,018,095 meters, the Conformal maps such as Stereographic with distance of 15,897,194 Meters and Polyconic with distance of 11,823,160 meters, the distances are different due to distortions. It shows the distance from the center of the projection. This map is commonly used for polar aspects and to find correct distances between two places. The conic projection has the same spacing between parallels or lines so the scale would look the same and constant. Because scales are not distorted, distance between places is accurate so if someone wanted to use a map to find the distance between two places for travelling, they can use equidistant maps.

In conformal maps, the meridians and parallels cross at right angles. Because the scale is kept only when this happens, this map is good for local mapping in a large scale and small area. Conformal maps are not equal area so it would not be good to use it for statistics in an area, area density or population size in a place. Conformal maps also preserve angles so if someone wanted to find angles where the meridians and parallels, then conformal is useful. It is also useful when viewing a local map because it is not distorted.