Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Units, Projection, and Scale

In Kentucky, eight different coordinate systems for spatial information are in use by state agencies alone. No doubt, other states share this problem. How should distances on a map be presented—metric or otherwise? What shows up on the product should take into account the nature of the audience. If you can, avoid cluttering products with multiple coordinate systems. If the user doesn’t mind the maps looking weird, you might make the map using latitude and longitude coordinates. Usually though, users like maps whose scales are consistent in all directions.