Image overlays provide additional information about the underlying earth imagery. For instance, you can use a map of satellite weather data that updates to reflect the most recent weather imagery for that region, or use publicly available image maps (or create your own image maps) for such things as hiking trails, camping spots, theme parks, fishing locations, national park boundaries, and more. One of the most attractive features of overlays is the ability to use imagery of a site plan and parcel boundaries to view the development stages over a particular parcel. The following exercise demonstrates this.
Overlaying an 1883 Ithaca Sanborn Map on the Current Google Earth Map
1. Right click on this link, then select "save target as", then keep the title, IthacaSanB2.jpg, but save it on your desktop.
2. Click on "Add an image overlay", go to "Browse" and select the same file.
3. Use markers to adjust orientation and opacity to your liking:
- central cross-hair slides the entire overlay and positions it from center
- quadrangle rotates image
- corner cross-hairs skew/stretch image at selected corner
- side anchors stretch image in/out at selected side