Lab #3 Exercise 13

Map  13a

Map 13a playing with the legend/colors

Map 13b step 5

Map 13b

Map 13b playing with the legend/colors

Questions for Exercise 13
1. Which projection(s) is/are used in exercise 13a?
2. Each dataset has a defined “datum”, but is not necessarily projected. After going through the tutorial, which datum seems to be the most common? (We will discuss projections and datums in class).
3. Using the internet, what is the largest U.S. state in area?
4. In step 19 of exercise 13a, which state appears largest?
5. Export a separate map following step 5 in exercise 13b.
6. Once you have correctly established the matching projections, describe the off-set between the Albers and Lambert projections in exercise 13b as seen in step 5 (for example, where are the cities located on the diagram in relation to their actual locations). Use your two maps for comparison.

Answers for Exercise 13

1.  In exercise 13a three versions of the Albers equal area conic projection are used.  Each of the three data frames use the Albers equal area conic projection, but the projection settings are customized for each to represent the area of interest as accurately as possible. 

2.  The shapefile  of the U.S. states (Datum NAD83) is used in all three data frames, but different projected coordinate systems are used for each data frame.

3.  The largest U.S. state in area is Alaska at 663,267.26 square miles.

4.  Texas appears to be the largest U.S. state at step 19 in exercise 13a.

5.  see above

6.  The layout view of the Lower 48 before and after projection differs in that before the projection all the cities appear east and south of their actual geographic locations.  The city locations show properly after the projection is changed to North American Lambert Conformal Conic.