Week 5 Projections GIS 4043

This week we were working with coordinate systems. It's important to know these systems and to learn how to use them and/or change them in ArcGIS. My take away this week is that I need to ensure my data is projected in a similar fashion across the board. Though on a larger scale coordinate systems may not make much of difference if there is a conflict or if the chosen system is an ill fit for the area in question, however, it does begin to matter when working with data in detail.

For the lab, we had to work with the Florida county maps and change the projections. (See below).  When I changed the format to UTM from Albers, I noticed that the UTM map became more compacted. The State Plane N, coordinate seem to distort the counties in the south while keeping the northern counties, particularly in the panhandle, un-distorted (not stretched out or compacted.) We then worked with a raster image of UWF. It had no assigned coordinate system. We had to define the system for it, by going to the properties and clicking the edit button to change the features. State Plane N seem to place the image in the correct location. When I did it in Albers, the image was no where near where UWF is in reality. It was interesting to see how different projections impact the map and the data over all. (Which also means that programs like Google earth, must be constantly changing projection as you zoom in and out.) State Plane N obviously worked the best with the raster image it was projected primarily for northern Florida. 

This was a week in which we dug deeper into ArcGIS and understanding how to prepare data we'll be working with in Arc. Of the lessons thus far, I feel this was probably one of the most important to learn and understand.

Comparison of Coordinate Systems using the State of Florida and selected counties. It shows how the square mileage of a given area can change (quite a lot) as the projection changes. At first it's hard to see the the changes, but looking from a slight distance, you can see the distortions.