Downloading Aerial Photographs

The first time you run USAPhotoMaps, a dialog box appears that prompts you to create a new map. You need to enter the following:

• What you want to name the map.
• The coordinates of the area you’re interested in viewing. The coordinates can be in either

• Latitude and longitude
• Universal Transverse Mercator (UTM)

If you don’t know the latitude and longitude coordinates of the location you’re interested in seeing, quickly skip over to Chapter 11 to read how to find coordinates of place names.
As an example, create an aerial photomap of Seattle, Washington.

1. Enter the name, latitude, and longitude in the New Map dialog box.
• Name: Seattle
• Latitude: 47.61431
• Longitude: 122.32898

2. Click OK.
A series of gray squares appear onscreen.

3. Download aerial photos from TerraServer-USA for the area that you specified (with the latitude and longitude coordinates). Make sure that you’re connected to the Internet and then press the F key.

A mosaic of aerial photograph images replaces the gray squares as the screen is filled with data from TerraServer-USA. The final result is shown in Figure below.


If you’re using a firewall, your computer might complain when USAPhotoMaps tries to connect to TerraServer-USA. Because the program is just downloading map data, you can give permission for USAPhotoMaps to access the Internet. If you plan to use USAPhotoMaps to build an extensive aerial photo collection, a high-speed Internet connection will make your life much easier. Each individual aerial photo or topographic map image in the displayed mosaic is roughly 50–200K in size. (The actual size depends on how much unique terrain is shown in the image.) At 2 meters-per-pixel resolution, it takes 70 images to fill the screen of a 1024 x 768 monitor; that’s anywhere from 7–17MB of data to download.