GPS satellites orbit the earth at an altitude of approximately 20,200Km. GPS is an aerospace technology that uses satellites and ground equipment to determine position anywhere on Earth.
Garman GPS uses twenty-one operational satellites, with an additional three satellites in orbit as redundant backup. The satellites continuously broadcast position and time data to users throughout the world.
The whole idea that GPS is dead is crazy. The usefulness of a GPS is now well recognized and interest is increasing all the time. GPS units typically will not work indoors, underwater or underground. GPS receivers have been miniaturized to just a few integrated circuits and so are becoming very economical. GPS receivers are very low power devices.
The Garmen units have an extensive database of locations and the excellent interface makes it easy to search the database to find what you want. Each satellite transmits a navigation message containing its orbital elements, clock behavior, system time and status messages.
Navigation via cell phone is a novelty and Garman will be around for a long time making quality GPS devices. There are so many countries where GPS is still not used that the future of GPS sales is ensured for at least a decade.
