Lab 6

Geographical  Coordiante System:
GCS_North_America_1983

Extent (in degrees):
Top: 34.236
Left: -120.368
Right: -119.503
Bottom: 34.871

The DEM above gives a small portion of the Santa Barbara bay area in Southern California. The reason for me to choose this specific area for this lab is that the rise and fall in this area with the comparison of the land and sea. Either in the aspect and slope perspective, it is clear to distinguish the sea. In the aspect, we can see the elevation in this area. Also, in the third picture, only a small area shows high slope in this area. Moreover, the with a little higher range, the elevation is clear even though it does not look real.

Lab 5

Distance from Washington D.C. to KaBul
Mecator: 10112 miles
Stereographic: 9878

Distance from Washington D.C. to KaBul
Two Point Equidistant: 8341
Azimuthal Equidistant: 6648

Distance from Washington D.C. to KaBul
Bonne: 8329
Hammer_Aitoff: 6731

The six different maps above are six map projections containing different attributes. Map projection is a transformation that gives the 3-D world a flat face, which we can see in the maps above. Map projection can only hold certain different attributes for different use of a map. There are three preserved properties map projection, conformal, equidistant, and equal area. For different reasons of using a map, the properties that fit the requirement will be different leading to choose different type of projections. Conformal map projections preserved the local angles and shapes. Equidistant preserved the distance from a point to the center of Earth. Equal area preserved the proportional area on Earth. The maps above are distinguished by the different preserved properties each one has, not the types they are. Besides the preserved properties, map projection has three types, cylinder, plane, and cone.

The first two maps in the first picture are conformal, which means that the map have the same shape as the real world. As we can see in the Mecator map, each continent is the shape of the real world. On the other hand, the distortion is clearly shown in the map. The longitude is straight up near the north and south pole. However, as we know that the longitude should be come together as we close to the poles. It is more accurate near the equator than in the poles. As in the Stereographic map, the area of China is almost as big as Russia. Because of the distortion in the map, the distance from Washington D.C. to Kabul should have a difference between in the map and in the real world. The distance in the Mecator map, 10112 miles, and in the Stereographic, 9787 miles, comparing to the real distance, 6940 miles, has a significant difference.

The two maps in the middle are equidistant maps. The equidistant map does not mean that proportional the distance in the map is equal to the distance on ground. The equidistant means that the length for some particular reference points are preserved. The Two Point Equidistant map preserves the distance from any point on the map to two chose point. With different "control point" or the point people choose, the distance may be different. On the other hand, the distortion in the map is clear. The area of the Antarctica is obviously smaller. The Azimuthal equidistant map preserved the distance along the great circles radiating from the center. We can see how the continent shifted together with the distortion.    The difference between the real distance and  the distance on the map is not as large as the Conformal, giving more accuracy on the distance.

The last two maps are equal area. Equal area map projections preserved the proportional area of the ground. As we can see from the map, the large distortion of length and angles gives lots of errors of calculating the distance from Washington D.C. to Kabul. The other map has even more distortion. The heart-shape map changes the distance from one places to the other and the angles are clearly not preserved. With the distortions, the distance from Washington D.C. to Kabul may vary from one to the other. The six maps above show different preservation of certain property and the distortion of the maps, showing the importance of choosing the corresponding map for certain use.

Lab 4 (ArcMap)

The map I created above is the result of using the software ArcMap, which I believe is a great program for professionals. However, several pitfalls occurred during the time I was using. First of all, the connection with the file is pretty frustrating for me. I have never come across this kind of user-unfriendly software. The users have to connect the file on the computer themselves. It took me a long time to figure out how to connect to the file in my USB drive, which for me was not a happy experience. Moreover, it is a very complex software. Even though I had the tutorial with me, which is very long, it still took me a long time to finish the project. The ArcMap really is not a program for non-experts, who can use the Neogeography the user-friendly software. It took a lot time to learn the basic command to create a map. I cannot image how long it will take to good at it.

Despite the pitfalls of the program, the ArcMap really is a powerful tool to make a professional map. With its complexity, the software can do a lot of comparison, distinction, and other functions. After several hours of working with the tutorial, the map looks quite nice for me. However, I believe that what I know is just a small part of the functions in the program. The tool bars in the program is very useful and concentrating on creating a map, adding a legend or north arrow or scale bar is very easy with lots of properties user can change. Also, the layout view and data view are very functional.  I can view the map with different view to decide what I want the map to be. Moreover, when working with details, data view gave me a clear view if the detailed data so that it is easy to make a change. Finally, in the end of creating a map, exporting the map was very efficiency with many different types of outputs I can choose.

The ArcMap is a powerful software for making a map. Even though, the pitfalls may give people some awful impression, it is very useful for professionals. With all the potentials, creating map focusing different research would be more efficient and precise. The project on ArcMap was a unforgettable experience, I really hope to get to know ArcMap more along the class.