Library of Congress
Loc: Everyday Mysteries: What Is Gps?
Where are you and where are you going? Visit this site and learn the discovery and purpose of GPS, Global Position Systems.
Smithsonian Institution
Smithsonian Institution: Time and Navigation
Explore navigation methods by sea, air, and space, what latitude and longitude mean, how GPS works, about satellite navigation, and learn about professional navigators. Includes a timeline of developments in navigation from 1280 to the...