Module 6: Georeferencing and University of West Florida Bald Eagle Campus Map

 

This week's lab module topic was on georeferencing. The goal for this module was to georeference current aerial photographs and one copy of a building plan to update the UWF building dataset. Additionally, a Bald Eagle nest is located near the campus, so a 330-ft and 660-ft regulatory buffer was also created surrounding the nest location. 

Data: 

The two current aerial images and one engineering building plan was provided as JPEG images, along with a Roads, Buildings, and the Bald Eagle Nest Location. The images were added as raster data to the project map. Since I wanted the imagery to be placed exactly where it was taken on earth, I had to assign to the geographic coordinate system used for this map so that it matches the real world placement, which is also known as georeferencing. To do this, the image, with unknown coordinate system, was related to the world imagery basemap with the known coordinate system via ground control points. The points were added to the exact location of shared features that could be seen in both the aerial image and the world imagery basemap. For example, I used building corners, street junctions, light poles, or any other feature that can be easily seen and does not change over time (i.e. river boundaries). This felt a lot like "pinning" the new image over the old image with "pins." Ten points or "pins" were added to georeference the images. It was best to spread out these points, instead of clustering them together. The accuracy of the points is measured by the RMS error, calculated as "Forward" in ArcGIS Pro. A smaller RMS error usually means a more accurate image. However, it is best to go by the both the appearance accuracy and the RMS error calculation. A first order or second order polynomial transformation could be done on the image to stretch the image if needed but a higher transformation requires more points. The southern aerial image was created with a second order transformation. Similarly, an engineering plan for the proposed construction of Heritage Hall was also georeferenced in the same way. 

A new building polygon was also added, by tracing the building's rooftop edges seen on the georeferenced aerial photo. A new road line feature was also created using the SNAPPING feature to easily connect to existing road lines. 

A 330-ft and a 660-ft buffer were created using the MULTIPLE RING BUFFER tool to show the required buffer distances surrounding a Bald Eagle Nest, as regulated by the FWC's Bald Eagle Species Action Plan. A hyperlink to view a photo of the nest was also added to the attribute table for this point, which can be viewed in the link below: 

https://drive.google.com/file/d/14T1_BFsK3Qj1Qc8vn5925XvXaSzjH6zn/view?usp=sharing

Layout: 

This map contained a large amount of data, which made creating a map layout that shows all the map features difficult. I found landscape orientation fit the map the best. An inset map showing the location of the Eagle Nest was added to the top right to show the nest location in relation to the local area. Symbology was also set to show off the important main focus of the map, by setting those features to red. Labels were added to note the building and road names. Boxes placed at the bottom of the layout contained the north arrow, author, scale bar, data source, and title info, which separated these features from the map and made the layout look more organized.