Creating Layers in Google Earth

Creating Layers in Google Earth

Layers of information, such as maps, can be draped over the satellite imagery of Google Earth to create an effective GIS tool suitable for pre-fieldwork activities and for presenting data in Google Earth.

1. Save the image you would like to create as a layer in a suitable location in .jpeg format. You may wish to crop the image to the desired size using image editing software such as the freely downloadable Paint.NET

2. In Google Earth navigate to the area you would like to overlay the image and choose an overhead view.

3. On the top tool bar click on ‘Add Image Overlay’. A grid frame will appear over the GE image, there will also be a dialogue box. In this add a name for the layer then ‘Browse’ to find the saved .jpeg file. Click ‘Open’

4. The image should now appear in the grid area. The shape of this area can be manipulated to align the image (if a map) with the GE aerial imagery or to move to the image to a desired location and to make it the desired size. To resize the image the corners of the grid can be dragged with the curser, to move drag the central cross, and to rotate drag the diamond shape on middle left.

5. When attempting to align a map overlay it helps to change the opacity of the overlay image. This can be done by moving the transparency slider (found in the dialogue box) to the left. By lining up prominent features on the overlay map and on the underlying satellite imagery a satisfactory alignment can be achieved. This can be done best when the ‘terrain’ is turned off in the Layers list on the left hand tool bar.

6. A description for the layer can be added, and the altitude of the image chosen. In most cases ‘clamped to ground’ will be suitable, however by selecting ‘absolute’ an altitude above sea level can be typed in. This will result in the layer hovering at the chosen height above sea level; ground higher than the layer will protrude through the layer (this can be used to simulate rising sea levels for example)

7. When ready return the transparency slider to ‘opaque’ and click ‘OK’. The layer is now complete. When selected in the Places bar the transparency can be altered using the slider at the bottom of the bar. To edit a layer at any time right click on the layer in the Places bar and select ‘properties’.