Aircraft clock with gps time updating

06 Mar

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GPS - How It Works Satellite Navigation is based on a global network of satellites that transmit radio signals in medium earth orbit.

The basic GPS service provides users with approximately 7.8 meter accuracy, 95% of the time, anywhere on or near the surface of the earth. Department of Defense (Do D) for use by both the military and the general public.The navigation messages include ephemeris data, used to calculate the position of each satellite in orbit, and information about the time and status of the entire satellite constellation, called the almanac. In order of date of introduction, these are: L1 C/A, L2C, L5 and L1C.These systems all use a set of satellites, from which GPS receivers on land, air, and sea, can be used to determine their position from timed signals from their satellites (shown here in a picture by AOPA).And since light travels at 300 million meters per second, or 0.3 meters in 1 nanosecond (one billionth of a second), clocks must be sufficiently accurate to measure delays with a precision of the order of 9 nanoseconds (ns).GPS satellites transmit time values regularly, but if we put in consideration the time delay between the satellite and the receiver, the time value received wouldn't be accurate insofar as I know GPS receivers aren't able to determine their position until they've got accurate time.Our devices don't have any atomic clocks synchronized with GPS.If you link to or cite these materials, please credit the author, Peter H. If you have comments or suggestions, please contact the author or Ken Foote at [email protected], The Geographer's Craft Project, Department of Geography, The University of Colorado at Boulder. Users of Satellite Navigation are most familiar with the 32 Global Positioning System (GPS) satellites*.The United States, who developed and operates GPS, and Russia, who developed a similar system known as GLONASS, have offered free use of their respective systems to the international community.