June 22, 2005

Street Atlas 2005 USA (DeLorme, Windows 98/Me/2000/XP, $89.95 includes the Earthmate LT-20 GPS USB receiver, available at Amazon.com) is a terrific help for anyone planning a road trip anywhere in the United States or Canada. Load Street Atlas 2005 USA on a laptop, attach the tiny new (1½ x 2½ x ½ inches) Earthmate LT-20, and you have an invaluable resource for anyone who travels for business or pleasure, across town or across country.

Just type in your starting location and destination, and the program creates a custom set of directions and maps for your trip. The directions are amazingly complete, with route numbers, street names, turns, distance, and estimated travel time for each segment and for the entire trip. You can view all the information on screen and/or print it to take with you.

The program shows a large screen display of the map pinpointing your location and directions. If you stray from your route, the program offers to re-route you back on track. Want more? You can opt to have the directions spoken to you as well, informing you of upcoming turns and more. A special feature of GPS tracking is the choice of a high contrast display, which we found very easy to read even in bright light; it features directions (in an extra large font), with large curved arrows to indicate turns, distance and estimated time to the next two turns.

Or you can use the Earthmate LT-20 in a simple tracking mode to log your trip, long or short, for later playback and/or study. In either routing or tracking mode, a "bread crumb trail" shows your travels. And this newest version of Street Atlas 2005 USA also can understand your voice commands (needs microphone connected to your laptop). Voice commands such as "What is the next stop?" "Zoom in (or out)," "Be quiet," "Stop GPS," and that all-important, "Where am I?" will get you the requested info or action. You can also use Pocket PC and Palm OS PDAs or Smartphones and download route directions and/or maps from your computer (optional software needed). Customize your trip by adding stops along the way as well as your driving preferences for speed, fuel stops, start and stop time for each day, length of stay at each stop, and other details.

The program gives you the ability to do address-to-address routing, and this version contains more than six million streets, many showing their dual labeling, such as Main Street, Rt. 44. You can even draw in new streets, which then become part of the routable street database. Another feature designed to insure accuracy in routing is that highway interchanges have been matched to aerial photos. A new searchable truck/RV service stop listing includes information about fuel, food, and special services. There are more than 4 million updated keyword searchable places of interest, most with contact info included to help you find nearby gas stations, food, lodging, shopping, entertainment, hospitals and more. Using the Radar feature, you’ll get a listing of places of interest at a specified radius from the center of the displayed map or from your GPS position. A click adds any of these places to your route as a stop or destination.

Map display is wonderfully uncluttered and yet pinpoints all the streets and places of interest info you need. A three-way split screen shows a small wide-area map to help give you the big picture and a medium scale map for the area around the main map, while the main map contains all the details. There are 16 levels of zoom to help pin-point these details. GPS tracking functions even in the split screen mode. You can show more than one route at a time on your maps--very convenient for comparing routes.

The advent of affordable GPS (global positioning system) receivers adds another layer of safety and security in knowing where you are and getting accurate guidance about where you want to go.

GPS 101: GPS is a system of 24 or more satellites circling the earth in six orbital planes. The time signals broadcast by the satellites are compared by your receiver, and the very tiny time difference in the signal due to the different distance of the satellite from your receiver is calculated to determine latitude, longitude and height above sea level of the location of your receiver. The receiver needs signals from at least four satellites to get a 3D fix. For three signals, you get a 2D fix. Any GPS receiver must "see" the satellites to receive enough signal to use, but placing the receiver on the car’s dashboard is fine, since the signals come through the windshield. Go through a long tunnel, however, and you’ll lose the signal temporarily.

The satellites are owned and operated by the Department of Defense, primarily to aid in military operations. Two types of GPS signals are available from the satellites: one for civilian use and the other for military and governmental agency use. Positional accuracy for the civilian signal depends on several factors but is about 3 to 12 meters; for military, it’s classified but guessed to be centimeters.