Projections and ArcGIS Lab:

Helpful resources:

Bolstad Chapter 3: Geodesy, Datums, Map Projections and Coordinate Systems
Understanding Map Projections and Coordinate Systems (ESRI Virtual Campus)
ESRI Online ArcGIS Desktop Help

Answer the following questions.

Question 1) (5 points) What is projection "on-the-fly"?

Question 2) (10 points) Assume you have a GIS dataset for the United States whose coordinates are stored in the Universal Transveres Mercator system (i.e. the projection is Mercator). If you convert this dataset to produce a new separate dataset in the Lambert Conformal Conic projections, the size of the polygons representing each state will change. Explain why.

Question 3) Open the ArcGIS Help (look under Map Projections and Coordinate Systems : Projected Coordinate Sytems ).

a) (15 points) List the 4 main properties of maps that are subject to distortion with map projections

b) (15 points) List and describe the 3 main geometric-based projection types (one is conic)

Question 4) (5 points) True or False: It is impossible to display two datasets that have different native spatial reference systems in the same Data Frame in ArcGIS.

Question 5) (5 points) True or False: The Universal Transverse Mercator projection/coordinate system is a good choice for datasets with large East-West spatial extents (e.g. the state of Montana). Explain why or why not.

Question 6) (10 points) Describe the difference between a projected and non-projected coordinate system (also referred to as a "Geographic Coordinate System - GCS" in ArcGIS).

Question 7) (10 points) What is the spatial reference system (coordinate system, datum, map projection) of the Streets_from_Monroe_County dataset (see Sept9 dataset)?

Question 8) (15 points, 5 each) Add the Streets_from_ESRI.shp dataset (see Sept9 dataset) to an ArcMap session to answer the following questions.

a) What is the coordinate (latitude, longitude) of the intersection of Rock East Rd. and Rockport Rd. in latitude/longitude (GCS)?

b) Describe the steps you used to find your answer

c) What is the coordinate (X,Y) of the intersection of Rock East Rd. and Rockport Rd. in the Universal Transverse Mercator coordinate system (North American Datum 1927, zone 16 north).

Question 10) (10 points) Create a new version of the Streets_from_ESRI.shp dataset in UTM, NAD1983, zone 16 North (see ArcToolbox : Data Management Tools : Projections and Transformations : Feature : Project). Make a copy of this dataset and use the Define Projection tool (see ArcToolbox : Data Management Tools : Projections and Transformations) to assign the spatial reference of UTM NAD1927, zone 16 north to this new dataset. Overlay these two datasets.

What is the approximate X shift and Y shift between the NAD1983 and NAD1927 datums (you can use the Rock East Rd. and Rockport Rd. intersection for reference)?