<YourNameHere>
GEOG 603: Introduction to Geographical Analysis
Lab 4: Projections and Coordinate Systems
Question 1-1 (1 point): What is the datum for the Neighborhoods layer
NAD 27
Question 1-2 (2 points): What is the coordinate system of the Parks layer?
What datum is this coordinate system based on?
The projected coordinate system is StatePlane with Lambert Conformal Conic
projection and the datum is NAD 83. The geographic coordinate system is GCS
North America 1983.
Question 1-3 (2 points): What is the difference between NAD 1927 and NAD
1983? NAD 27 is based on 26,000 points that were done manually and NAD 83 has
250,000 control points done via satellite. NAD 27 has its origin in Meades Ranch
Kansas and NAD 83 has an origin at the earth’s center of mass. These factors mean
NAD 27 is a local datum and NAD 83 is a global datum.
Question 1-4 (1 point): What is the coordinate system of the Schools layer?
The coordinates shown in the extent box appear to be a latititude-longitude
coordinates, but the coordinate system is undefined.
Question 1-5 (1 point): What is the coordinate system of the Streets layer?
The coordinates shown in the extent box appear to be UTM coordinates, but the
coordinate system is undefined.
Question 2-2 (1 point): What is the purpose of defining a projection?
To ensure that the different datasets are overlaid on each other in order to avoid
datum shifts.
Question 2-3 (1 point): What is a datum shift?
When the origin and shape of ellipsoid differ between two datums and their
respective datasets end up not overlaying each other when projected.
Question 3-1 (2 points): What is the purpose of a geographic (datum)
transformation?
Since datums are based on varying ellipsoids, the coordinate values of one datum
will not integrate into the coordinate values of the other. Geographic
transformations take the varying coordinates from one dataset and adjust the values
so a datum can be referenced within another datum system.
(2 point) Insert your projected data map from Part 3 of the lab below.
Question 4-1 (1 point): Why are the circles distorting when you change the
projected coordinate system?
(2 points) Insert your projected world map below.
(3 point) Insert your world projection maps in layout view frothe lab below.