GIS4043 Projections Part I

The first part of this week's lab focused on comparing three different projections of Florida and how they affect area.  Flipping back and forth between the Florida projections in the ArcMap was helpful to see some of the differences inherent in projections. Until this lab I had no idea that there were so many projections in use.  The more I use ArcMap, the more I learn that there usually are multiple ways to complete any one task which has been quite helpful.

This particular map did not include an inset map.  Since the purpose of the map is to compare differences in area caused by different map projections, I figured that it would be used by someone either familiar with the location of Florida already or who was primarily interested in the concept of comparing projections themselves in which case the region to which the projections are applied is of lesser importance than the comparison itself.  A locator map would be extraneous in that case.

During the process of creating a map, ideas for improvements or different aspects to explore usually lead to changes in the original plan.  So even though I'll sketch a preliminary map, I may end up with a totally different product for submittal, sometimes having to choose from three or four different workups that evolved out of the initial sketch.  In some respects this is no different than working up different product options for a client to preview before committing to a final.

With this particular map, viewers can see that different projections can affect area figures, and so if accurate area is a priority, then a suitable choice of projection is imperative.  I'm looking forward to developing the expertise necessary to do that.

Four counties across Florida are compared for differences
in area calculated in three different projections.