ExpertGPS shows your GPS data on USGS aerial photos, using a UTM projection. As you move around the map, ExpertGPS will retrieve photos over the Internet and display them on your screen. The map server that ExpertGPS uses has aerial photos for most locations in the continental United States. Coverage is not available for much of Alaska, and in some parts of the Mountain West.
Working with Maps
Read about the basic commands for interacting with all of the maps in ExpertGPS.
Showing a Aerial Photo Map
To show a Aerial Photo Map, click on the .
Internet Map Retrieval
To allow ExpertGPS to retrieve aerial photos over your Internet connection, click on the .
Drag the 
Retrieve Maps Tool over a regional
map to queue up all of the aerial photos in that area for retrieval over your Internet connection.
How Old is this Aerial Photo?
USGS takes new aerial photographs when major changes to the landscape occur. The photos that ExpertGPS uses are the latest available from USGS.
To determine when a aerial photo was published, do the following:
- Select a waypoint on the map.
- On the , click .
- The Online Waypoint Viewer will appear.
- Click the Microsoft TerraServer link in the Aerial Photo section. The aerial photo's name and date of publication are listed above the photo.
