The process works by adding data that is already referenced. In this case, polygons and polylines of roads and buildings on the campus. We then added the raster data. Of course the raster doesn't line up. So we enabled the georeference tool bar. (Everything in ArcGIS comes down to the toolbar). In the tool bar we can first get the raster data to appear in the same space as the buildings/roads layer by selecting Fit to Layer. Then we enable the points. Using the buildings/roads layer, we can connect various points to points on the raster data. I can see the corner of a building, and connect it to it's corresponding polygon. You need to start with the unreferenced data and link it to the referenced data. You need to have at least 5 points.We can then check something called the RIMS error, this will tell us how close those two points are. The error should be under 15. I was able to get the error around 4 on the first raster while still making sure it looked accurate. Having it look accurate is as important as getting a good error value. So one needs to find the right balance. This balance is helped along by using polynomial transformation. There are three levels and the transformation helps to warp the raster data to the points. It can help create a more accurate look but if you use higher levels (as I discovered) it can stretch the raster out and distort it in various ways. The northern half of UWF used a level 1 transformation where as the southern hald used a level 2. Level three really distorted the image. After creating and deleting links I finally got something I felt good with.
We then had to create a buffer zone around an Eagle's nest using the multibuffer tool. This was the easiest part. Input, ouput boom...buffer zone! multi because we created two in one, 330 ft and 600 ft. There was no base map for where the eagles nest is. So I had to add a basemap..for some reason, every time I exported it as a jpeg, it distorted and created a pixalted green mess. I couldn't figure that out. We also used the editing tool to digitize shapes on the map. In our case, the gym and a road. The road was a polyline and the gym, a polygon. I had done this in the past using one of the free ESRI courses which has you digitize a lake. The tool is a little tricky. With the gym, I first tried making a square for each part of the building, but it was hard to line them up and merge them. I went on YouTube, find a viedo and realized there was a way to do it in one sweep...make a lot of little points that match the outline. Though, it didn't come out perfectly, I felt like it worked great.
The next part was the part that you can impress people with the most...no one cares that can you do an awesome job analyzing the best place to set this up or geo code, no the thing that gets the lay people interested are 3D maps! We put our now referenced raste data along with a DEM feature class in Arc Scene. Using the DEM plus the base heights of the buildings we were able to create a 3D map of UWF. This is actually a fun process that I really enjoyed in my Carto class. And your friends often say...ooooh...aaahh....even though in reality the process do it is quite simple despite the number of steps.
Overall this lap helped us to better understand some of the basic mechanics of ArcGIS and how georeferences can be created when none are found. As I near the end of the course, I feel more confident in using ArcGIS...I'm also happy I saved all of those pdfs on my pc so I can look them up when in doubt!
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