6 Map Projections in ArcGIS Week 6 Lab5 Assignment

For the Bonnie Map, the Distance Between Washington D.C. and Kabul 

was about 6,774.958205 miles

For the Goode's Homolisine Map, the Distance Between Washington D.C. and Kabul

 was about 9,974.699803 miles

The Kinds of Map Projections that are seen above consist of three different kinds:Conformal, Equidistant, and Equal Area projections. There are Positive and Negative things about each kind of projection. There is no projection that will be able to preserve every element that the real world. Therefore, there are different projections that serve for different things.

One of the first Map projections that was shown above is a Conformal Projection. Above, you see a Mercator and a Conformal Conic projection. A Mercator projection has straight verticle meridians and this is good because it allows direct bearing measurements. One other good thing is that at any point on the map the scale is the same in all directions and they tend to preserve shapes in small areas. Moreover, conformal maps preserve the angle details as you convert from three dimensional to two dimensional. Relative angles are correct at each point of the map in a conformal projection on a conformal Projection, directions are locally true, but are distorted with distance, so in a way a conformal projection can preserve direction from a single point, it is really hard to preserve direction on any kind of projection. Conformal maps are best at measuring angles, looking for accurate local directions, or when you try to represent contour lines. The best uses for this kind of projection are for navigational reasons and also for meteorological reasons.

Equidistant projections are those that maintain a more accurate distance in a map from the center of the projection or also along given lines in the projection. I found it interesting that it is used for seismic mapping because that kind of mapping would be useful and interesting here in California due to our prevalent plate tectonic movement along the ring of fire and the higher possibilities of different size earthquakes.The projections used above were an Azimuthal and Sinuosidal, What I noticed in these two different projections was that when i was measuring the distance in miles in Arcgis, the distance for both were really closely similar. Which proves that within two points the distance between those two points is more accurate. In the first two projections the conformal conic and the mercator both gave different distances between the two same points and were not even close but thousand of miles of a difference.

An Equal-Area projection preserves the area and the areas anywhere mapped on a plane, maps show accurate sizes. This kind of map can show true direction from the center point of the map. The two projections above are Bonnel and Goode Homolosine. The scale on an equal-area projection is constant along the central meridian. The scale on the east and west is also constant throughout the map. For this kind of map the true distance within two points are measured on the meridian and are measured at two points in two parallel lines that intersect the meridian. Maps that preserve area such as these two projections, show the area of something on a map proportional to that something on the real world. This kind of map can be useful when looking for the density of population in different areas as well as how much land is being used by different factors in an area, or figuring out different things about an area, there are a lot of different categories one can map about. The cool thing is that along the central meridian there is no distortion. One negative things is that an equal-area projection could never be conformal.

In order to look for a good projection that you might need you need to know what you are looking for especially looking for a good projection that minimizes distortion in the location that you are interested in. The different projections try to help keep a balance distortion of the shape of a map as well as the area of a map, to try and get us to use the different projections for specific uses. There is no single map that will have both Equal-Area and be conformal ect.. therefore, we use these projections to best figure out things about the world while working with a two dimensional map. Although, there are distortions to every kind of projection they are all extremely important and useful.