By capturing the signals from satellites, GPS receivers are able to use the mathematical principle of trilateration to pinpoint geographic locations. With the addition of computing power and memory such as road maps, points of interest, and topographic information, GPS receivers are able to convert location, speed, and time information into a useful display format.
The Invention and Evolution of GPS
GPS was originally created by the United States Department of Defense (DoD) as a military application. The system has been active since the early 1980s but not become available to civilians until the late 1990s. Consumer GPS has since become a multi-billion dollar industry with a wide array of products, services, and internet-based utilities. As with most technologies, its development is ongoing; while it is a true modern marvel, engineers recognize its limitations and work continuously to overcome them. GPS Pros and Cons
An International Effort
The U.S.-owned and -operated GPS is the world’s most widely used space-based satellite navigation system. Russia’s GLONASS satellite constellation also provides global satellite navigation service. Some consumer GPS devices use both systems to improve accuracy and increase the likelihood of capturing sufficient location data.
Interesting Facts About GPS
The workings of GPS are a mystery to many of the people who use it every day. These points may surprise you:
Military GPS uses two frequencies, while civilian uses only one. This increases accuracy. Dual-frequency GPS devices are available to civilians, but their cost and size makes them impractical. The U.S. government is engaged in an ongoing, multibillion-dollar improvement and modernization program. U.S. taxpayers fund the world’s GPS services, mostly through the Department of Defense. The 2017 budget was about $900 million. An American joint civil/military body—the National Executive Committee for Space-Based Positioning, Navigation, and Timing—oversees the GPS. The U.S. Air Force maintains and operates it. As of 2017, 24 GPS satellites circle the Earth. GPS is essential to devices, conveniences, and services we take for granted every day, such as cell phones, watches, computers, weather forecasting, energy delivery, navigation, and emergency/disaster response. Many industries rely on the accuracy of GPS, including banking, construction, aviation, shipping, and agriculture. GPS is crucial to national security. All new military equipment is GPS-equipped. GPS informs the world’s air, sea, and road transportation systems.
