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| | FAQ - GPS Basics |
 | | GPS is used to support land, sea, and airborne navigation, surveying, geophysical exploration, mapping and geodesy, vehicle location systems, farming, transportation systems, and a wide variety of other additional applications. |
 | | The basic GPS signal is accurate on a worst-case basis to within approximately 100 meters lateral and 140 meters vertical everywhere on earth. |
 | | A. GPS is a satellite-based radio navigation system, initially developed in the early 1960s and operated by the U.S. Department of Defense (DOD) since then. |
| gps.faa.gov /FAQ/faq-gps.htm (2712 words) |
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