GPS technology has revolutionized how we navigate and explore the world. Beyond helping us find our way, there are many lesser-known aspects of this remarkable system. Here are seven interesting facts about GPS that showcase its complexity and importance.
1. High Operational Costs: Operating and maintaining the GPS system costs approximately $2 million each day. This expense, which includes satellite launches and regular maintenance, is covered by American tax revenue.
2. Automatic Deactivation: GPS units are designed to shut down if they detect speeds over 1200 mph (1900 km/h) at altitudes above 60,000 feet (18,000 meters) to prevent misuse in high-speed, high-altitude applications such as intercontinental ballistic missiles.
3. Relativity Adjustments: Due to their high speeds, GPS satellites experience time differently. According to Einstein’s Special Theory of Relativity, a second on a GPS satellite is 8 microseconds longer than a second on Earth. GPS systems are programmed to account for this discrepancy.
4. ‘Death by GPS’ Incidents: Some users have ended up in dangerous situations by blindly following GPS instructions, leading them off cliffs, into lakes, or deep into deserts. These incidents highlight the importance of paying attention to the real-world environment rather than relying solely on digital directions.
5. Selective Availability (SA): In the 1990s, civilian GPS accuracy was intentionally degraded by a feature called Selective Availability (SA). This changed in 2000 when President Bill Clinton ordered SA to be turned off, significantly improving GPS accuracy for civilian use.
6. Impact on Navigation Skills: Research suggests that heavy reliance on GPS can diminish our natural ability to form and use mental maps, potentially weakening our innate navigation skills.
7. Space-Based Navigation (XNAV): Scientists are developing a new type of GPS for space travel. This system, called XNAV, uses X-rays from pulsars to provide precise location information, accurate to within 5 kilometers, anywhere in space.
These facts reveal the intricate workings and profound impact of GPS technology, reminding us of its critical role and the importance of using it wisely.