GIS 6005 - Communicating GIS - Module 2

Deliverable 11:

State your area of interest. Briefly discuss which coordinate system you selected for that area of interest and why. Express why the other options were less appropriate.

            I chose the State of Pennsylvania as my map focus, and more specifically the Philadelphia area of the State of Pennsylvania. This is the city in which I live, and most of the GIS projects I end up working on are located locally. I chose a state plane projected coordinate system, and more specifically the NAD 1983 (2011) StatePlane Pennsylvania South FIPS3702. Because Pennsylvania is fairly big (by the standards of the American Northeast), there are actually two state plane systems: north and south. Obviously, because the City of Philadelphia is situated in the very southeast of the state, I decided to select Pennsylvania south for the purpose of this project.

            The state plane projected coordinate systems tend to be very accurate when focusing on a fairly small area. The distortion of the grid is apparent within a few states, and can be seen very clearly when viewing all of the United States. The area of focus, however, lends itself well to the grid. I chose not to use a UTM based system, as the state of Pennsylvania falls at the exact center of two UTM lines. After browsing through the State Systems list, I did not see anything specific to Pennsylvania, and therefore wen with a more familiar choice.

Deliverable 8:

Provide the name and complete details of your coordinate system.

I picked the Nova Scotia province for my point of interest. Of the two Projected Coordinate Systems that appear on the list, I selected:

ESRI Projected Coordinate System: ATS 1977 MTM 4 Nova Scotia

Projection: Transverse Mercator

WKID: 2294

Authority: EPSG

Linear Unit: Meters (1.0)

False Easting: 4500000.0

False Northing: 0.0

Central Meridian: -61.5

Standard Parallel 1: (NA)

Standard Parallel 2: (NA)

Latitude of Origin: 0.0  

Geographic coordinate system: GCS ATS 1977

WKID: 4122

Authority: EPSG

Angular Unit: Degree (0.0174532925199433)

Prime Meridian: Greenwich (0.0)

Datum: D ATS 1977

Spheroid: ATS 1977

Semimajor Axis: 6378135.0

Semiminor Axis: 6356750.304921594

Inverse Flattening: 298.257