11. You can also look up your SPC zone number and name using http://stateplane.ret3.net/ 12. Answer the following: a. Describe the State Plane Coordinate system in your own words. b. Why are eastings and northings expressed in meters rather than degrees? c. Are SPC coordinates projected? How? d. Are there zones in this system? e. What are the two projections that are used for SPC? f. How do State Plane Coordinate systems’ projections differ among the 50 US States? Why? Comparison between the three systems 13. Finally, compare and contrast the three coordinate systems in your own words—consider appropriate usage, accuracy, and ease of calculation. Include answers to the following: a. Why are some coordinate systems projected and others not? b. How do the systems compare in terms of accuracy of measurement? c. What geometric property is preserved in projected coordinate systems, and why? d. Compare the systems in terms ability to calculate area and distance measures? Why are some systems better than others? e. When would you use one or the other? Explain these different use cases in terms of scale and mapped location. Part B: Map Projections, comparing Mercator to everything else Even if you look at maps every day, you probably don’t think much about the process of how the globe (a 3D surface) is transformed into a map (a 2D surface).