Lab 6

GCS distance from Washington D.C. to Kalbu: 7835.028179 Miles

Mercator distance from Washington D.C. to Kalbu: Length: 10,112.118968 Miles.

The characteristic of conformal map projection is to preserve angles, so it distorts the area and distance on the map. The pitfall of this type of map projection is that it distorts the actual shape and area of countries. For example, the World Hotine completely alter the shape of the normal map we usually see. But the angles demonstrated are precise and accurate. In my opinion, this type of map projection is the most confusing and misleading one.

World Eckert IV distance from Washington D.C. to Kalbu:7,835.028179 Miles.

World Cylindrical Equal Area distance from Washington D.C. to Kalbu: 10,108.051114 Miles.

Although these two are all equal area projections, but the outcome of the features are different. The World Eckert IV projection distorts the features around the North and South poles. It is more of a spherical projection rather than a flat one (World Cylindrical Equal Area projection). While both of them preserve the actual area, the shape, distance and angles are distorted. Such map projection is often used for big area like the entire world, and mainly focuses on the areas around the equator. A potential of this type of map projection is that its contents are always accurate.

World Azimuthal Distance from Washington D.C. to Kalbu: 8,426.406105 Miles.

World Equidistant Cylindrical distance from Washington D.C. to Kalbu: 5,061.578567 Miles

Equal distance map projection preserves the distance between reference points, and it is best used for small areas like cities. Thus the projection and estimation can be more accurate. Also it is commonly used by small countries.

In Azimuthal equidistant map projection, all distances measured from the center of the map along any longitudinal line are accurate, but the distances and directions to all places are true only from the center point of projection. Distance measurements are accurate between points. And other distances are distorted and thus incorrect. Distortion of areas and shapes increases with distance from the center point.

From this experiment of map projection, I learned different types of map presentations. Some of them preserve area and distance, and others preserve angles. Each map projection has distortion, thus some countries look different from the ones on normal maps. To illustrate the difference, this tutorial selected Washington D.C. and Kalbu as reference points. On different types of map projections, the distance measured also vary. Different map projections serve different purposes, including political, private and business expectations. The size of the selected area is also crucial when determining which map projection needs to be used. All in all, ArcGIS is a really helpful tool.