Our earth is a spherical, but when we want to use it for navigation or other purposes we need it in a 2-D dimension. Therefore, we need projections. From this lab, I find out that there are no perfect projection. They are either good at preserving the distance, or area, or angle. However, it distorts the map more or less. based on this fact, when we are using maps for different purposes, we should use different projections. Since they are all imperfect, they have a lot of potentials as well. After doing the lab, i learned a lot about projections which will help me in my future life since we need maps every where. But, again, all the projections are not perfect!
For Mercator projection, the distance
between DC and Kabu is about 10118 miles.
For Eckert 1 projection, the distance
between DC and Kabu is about 7410 miles.
The projection I do is conformal projection. It preserves the
angle and shape. Based on this advantage, it is often used to navigation
because the shape does not change. For example, I choose Mercator projection
and Eckert 1 projection. Eckert 1 projection
is often used as a novelty map and Mercator is still used in navigations. On
the other hand, however, it cannot preserve the area. We can see from the
pictures that the pole area is larger than usual.
Cylindrical equal area projection, the
distance between DC and Kabu is about 10108 miles.
Behrmann, the distance between DC and Kabu is
about 8760 miles.
Next projection is Equal area. Equal area projections preserve
the area. Statisticians may like it because this kind of
projection is helpful on their research of sizes. However, it cannot preserve
angle and shape. In addition, it can’t preserve the distance as well. Thus, it
is probably not a good choice to make maps because of these limitations. I
choose to make Behrmann and Cylindrical equal area projection.
We can see from the picture above that both of them have distortions towards
the poles.
For Azimutal
projection, the distance between DC and Kabu is about 8350 miles.
For equidistance
cylindrical projection, the distance
between DC and Kabu is about 8145 miles.
Last one is the
equidistance projection. This projection preserves distance in all directions.
Thus, it can be useful in comparing the length. For example, we can analyze the missile crisis on the South Korea
by using equidistance projection. I choose Behrmann and equidistance cylindrical
projection. We can see that the distance between DC and Kabu in these 2 projections is
very close to each other. However, in the picture, the shape of the map is not
accurate. For example, in equidistance cylindrical projection, the shape of all Continents are longer than usual. thus, it is not a good choice in navagation.
