Week 6 - Projections Part 2

 ... or was it Data Search Part 1?

This week's lab had us gathering spatial information off the internet, reprojecting it, and then putting it all together into a final cohesive whole (the map). We also created spatial data from excel spreadsheets, and converted coordinates from degrees minutes seconds to decimal degrees using a formula entered on the excel spreadsheet. The results of this lab can be seen below.

The majority of the data on this map came from internet derived sources.

Technical Notes

While there is quite a bit going on with the visual part of the map, such as the two insets to show the map location, the real story took place behind the scenes.

My first step was to import an excel spreadsheet of the petroleum storage tank locations. I ran into some snafu's when it came time to put a projection on it, and if it wasn't for the class discussion board I'm not sure how long it would have taken me to treat this as a two-step process. My issue was with defining a correct initial projection - I was trying to fit data from a lat./long. source into a State Plane grid! That won't happen (well, correctly anyway) without first taking the proper steps. Since I had converted degrees minutes seconds into decimal degrees, I needed to assign a lat./long. projection - in this case, WGS84. Only after I set up the GCS to an appropriate system could I then reproject to State Plane Florida North US Feet (the projection required for this lab).

After viewing the storage tank data, I decided to focus my map on the Bratt and Century quads... but it quickly became very clear that in order to have some semblance of consistency, I needed to add more aerials! So the majority of my time was spent downloading aerials from Labins.org (a website of survey data for Florida, hosted by the Florida Department of Environmental Protection), then extracting them. In all there are 8 quads represented on my map - only 2 of which were absolutely required.

The roads, quad index, and county boundary data were also obtained online... this time from the Florida Geographic Data Library (FGDL). It's a source that had already been used several times over in this class. All of the data had been converted from Albers to State Plane Florida North Zone NAD 1983 US Feet, using the project tool.

In all I found this lab very useful - and I've already started to bookmark credible sites with free spatial data downloads for the western U.S.!