Adding Accurate Location to Satellite Imagery
Satellite or remotely sensed imagery are valuable sources of information about the Earth’s surface. In this exercise, imagery is geo-referenced so that the image features are accurately located in its actual location on the surface of the Earth.
A: Getting imagery from Google Earth
- Open Google Earth and navigate to the area that you want to copy
- Zoom to the extent of the image needed for your purposes
- Copy the Image (Edit Menu -> Copy Image)
- Paste into an editing software such as MS Visio, Photoshop, Adobe Illustrator or even MS Powerpoint
- Edit the image by cropping or transforming as necessary
- Save the image as a tif file and name it “Island1.tif ”
B: Orthorectifying (1)
- Open the Saved ArcMap File in Exercise 1
- Zoom to the island that you have the satellite imagery for using the FJI_adm0 layer
- Add the previously save tif file “Islands1.tif ” to your layers
- Click on OK when the unidentified projection warning is displayed
- Place the “Islands1.tif ” layer on top of the FJI_adm0 layer
C: Orthorectifying (2)
- Turn on the Georeferencing Toolbar (Customize Menu>Toolbar -> Georeferencing)
- Select “Islands1.tif ” in the Georeferencing Input box
- Select Fit to Display (dropdown menu of the Georeferencing
- Toolbar) to show image
-
Enable the Effects Toolbar (Customize->Toolbar->Effects
- Set the transparency of the Islands.tif layer to 35% to show the
Island outline
- Use the Rotate, Shift or Scale buttons of the Georeferencing Toolbar to make the image
nearly the same shape as the administrative layer