Week 6 Lab: Rubber sheeting w/ the georeferencing toolbar

Georeferencing practice (Oconee Forest Park)


Set up your ArcMap project

  • Load your georeferenced source image (NAIP2015_Source.jpg)
  • Ensure your data frame coordinate system matches the NAIP (UTM17/NAD83/Zone17N…)
  • Load your ungeoreferenced target image
    • this layer is not georeferenced, you will not see it when it loads
  • Save the project to your workspace

Locate possible ground control points (GCP)

  • GCP should be stationary object, low to the ground, easily observed on both the target and source images
  • road intersections, edges of sidewalks, bases of monuments, etc

ArcMap procedures:

  1. Load the georeferencing toolbar (right-click on the grey banner at the top > select Georeferencing from the list) GCPToolbar
  2. Specify your ungeoreferenced target image as the georeferencing layer
  3. Zoom to the area of interest on the source image, in this case the OCFP source image, and fit your target to display (Georeferencing pull-down > Fit to Display)
  4. Move your target image to the top of the TOC
  5. Insert GCP #1
    * Zoom into the first GCP in the ungeoreferenced target image
    * Grab the GCP tool (greenX/red button to the left of the drop-down)
    * Click on GCP location in the target image
    * Zoom to the same GCP location in the georeferenced source image
    * With the GCP tool, click on the GCP location in the source image
    * Repeat for at least 3 more GCPsGCPToolbarGCPLink
  6. After inserting four GCPs, evaluate your RMSEGCPToolbarRMSE
  7. After inserting at least 6 GCP and with an RMSE of <= 0.55, apply the georeferencing solution
    * Use the Update Georeferencing entry under the Georeferencing pull-down
  8. Use the Define Projection (Data Management) tool to define the source raster’s coordinate system
    * Define the CS to match the CS of the original source image.