GIS4043 Week 13: Georeferencing, Editing & ArcScene

Georeferencing, editing and ArcScene were the areas of emphasis while creating two maps of University of West Florida campus. The location of a bald eagle nest on the eastern side of the campus was included in one map. For the first map, aerial photos were brought into a spatial relationship with known points through the use of carefully selected control points. After associating ten points (unknown raster image locations) with the corresponding known building points, the Links Table was reviewed for the total RMS Error. Control points were deleted and additional ones were linked as needed to meet RMS Error criteria along with attaining an accurate appearance. The RMS Error and transformation were recorded before updating the georeferencing which resulted in the image coordinates being converted to real world coordinates. (The recording of the information happened on the second go-around for me, since I forgot to do it the first time.) The new gym and Campus Lane were digitized and added to the pertinent attribute tables through the use of Editor. The important aspect of editing (which I learned in a less convenient way in an earlier lab in which I had experimented with Editor) is that edits must be saved or they will be lost when ArcMap is closed. 

University of West Florida Campus Buildings, Roads

 and Bald Eagle Nest: Georeferencing Aerial Images

and Editing Procedures

A bald eagle nest near the trails on the east side of the campus was included in the map along with two buffer zones, the larger of which is a 660 foot radius. Given that Florida Fish and Wildlife Commisssion acknowledges that their coordinates are accurate to 0.10 mile (528 feet), the buffer zones seem a bit on the low side in my opinion. A hyperlink to a photograph of the nest was included in the map as well.

The ArcScene portion of the lab provided an opportunity to experiment with three-dimensional display of data. After draping the roads, buildings, and image layers over a DEM layer, the buildings were extruded and their heights exaggerated. Playing around with ArcScene was nauseatingly fun. Eventually an image was exported and then used in ArcMap to create a second map of UWF campus. Everything seemed rather straightforward and fun to use for this lab, but an issue that consumed quite a bit of time to resolve was eventually determined to be a relatively easy fix. The exported image resulted in a very pixellated ArcMap document. After a lot of re-checking and re-doing of maps, it was found that the image quality setting had been reduced. Once that was fixed, the image and map were much better. This was also an opportunity to try ArcGIS for Desktop a second time. In an earlier lab there were too many issues to make it worthwhile, but this lab was easy to complete and much more quickly done on personal desktop rather than in eDesktop.

3D View of University of West Florida Campus

The georeferencing and digitizing were especially fun to do, and more is anticipated. As a side note, some of my young charges and I were able to witness one of the resident ospreys shooing a juvenile bald eagle away from the osprey nest on our own school's campus today. The size difference between the birds was impressive!