| By comparing the received sequence with the original sequence, scientists can determine how long it takes for the signal to reach the Earth from the satellite | Amos, Jonathan February 12, 2019 |
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| The receiver then separates the signals into different channels designated for a particular satellite and frequency at a particular time | The first segment of the system consists of 24 satellites, orbiting 20,000 km above the Earth in 12-hour circular orbits |
The radio signals are sent at two different L-band frequencies.
23| Developed by the Department of Defense in 1973, GPS was originally designed to assist soldiers and military vehicles, planes, and ships in accurately determining their locations world-wide | 1999 46 11 25933 1999-055A IIR NAVSTAR 47 USA 150 E1 11 |
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| 1993 37 7 22657 1993-032A IIA NAVSTAR 33 USA 92 A1 26 | This creates six orbital planes which completely surround the Earth |
, GPS History, Chronology, and Budgets• Jury, H L, 1973, Application of Kalman Filter to Real-Time Navigation using Synchronous Satellites, Proceedings of the 10th International Symposium on Space Technology and Science, Tokyo, 945—952.
| 2004 59 19 28190 2004-009A IIR NAVSTAR 55 USA 178 F4 23 | 1996 33 3 23833 1996-019A IIA NAVSTAR 38 USA 126 E3 16 |
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| 1992 26 26 22014 1992-039A IIA NAVSTAR 27 USA 84 A4 09 | Within each signal, a coded sequence is sent |
2003 47 22 28129 2003-058A IIR NAVSTAR 54 USA 177 C3 20.
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