As we have said many times, it's all about the data! We have covered in these pages a number of commercial products that offer digital maps and photometric data for use by GPS plotters. We introduce you, here, to USA PhotoMaps, a "shareware" product that can be downloaded from the Internet. Retired airline pilot Doug Cox wrote USA PhotoMaps for his own use. He wanted a way to download and use the map database available from Microsoft's TerraServer. The program is now in its second version, but updates of the program seem to appear monthly as Mr. Cox improves it. As this program is distributed as shareware, the author would greatly appreciate a voluntary payment for use of the program.
Using The ProgramWhile USA PhotoMaps is a very useful program, it does not have a "bells and whistles" graphics interface. Most commands are implemented by keystroke. (It is much like using DOS.) For example, after telling the program to show you a specific location, the program presents a gray screen. Tapping the F key downloads the default photomap - a 1-meter-per-pixel, black-and-white photomap. Using the "-" key will zoom out the image out three levels before a smaller-scale image - 8 meters per pixel - will want to load. Just push the F key. Want to see the USGS 7.5-minute quad for the area? Just press the T key and then the F key to load the maps. The quads, like all the maps presented by USA PhotoMaps, are stitched together for seamless presentation. For some urban locations, (unfortunately not off-road areas) pressing the U key will switch the view to a 0.3-meter-per-pixel, color view. See illustrations on the following page for samples of the imagery. Look carefully at the top of each image for our editor's office!
If you want, USA PhotoMaps can be used as a real-time plotter. Just hook up any GPS unit to a laptop and download the maps for the area you plan to cover. When under way, start the program and tap the space bar. Your track will then be presented on the screen overlay on the map of your choice. The track will also be saved to an Excel file for future review.
Other Cool Programs To TryMicrosoft is now offering MSN Virtual Earth in beta test version. It is fun to try. The real killer app in geography fun is Google's GoogleEarth at www.earth.google.com. If you have broadband Internet, download it and fasten your seatbelt - it's a fun "geo-ride!"
USA PhotoMaps allows you to download and view any USGS 7.5-minute quadrangle topographic quad for the U.S. You can also download the USGS 1-meter-per-pixel, black-and-white photomap of any area. For some urban areas, a 0.3-meter-per-pixel, color photomap from the USGS is also available. USGS vector highway, street, and trail data, as well as topographic contours, can also be downloaded and overlaid on all available images. Street addresses, populated places, and other data can be downloaded, which helps in location search, and the program also allows the creation of waypoints and routes for uploading into a GPS unit, and the downloading of GPS track data to display your trip on the maps you have downloaded. It will not, however, auto-route in the manner of commercial navigation programs.
USA PhotoMapsWritten by Doug CoxDownload at www.jdmcox.comThe program is shareware a payment for use is warranted. (The author reports the average payment is $25.)
TerraServerOffered by Microsofthttp://terraserver.microsoft.comFree