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GPS receiver manufacturers design GPS receivers to use spectrum beyond the GPS-allocated band. In some cases, GPS receivers are designed to use up to 400 MHz of spectrum in either direction of the L1 frequency of 1575.42 MHz, because mobile satellite services in those regions are broadcasting from space to ground, and at power levels ...
The United States' Global Positioning System (GPS) consists of up to 32 medium Earth orbit satellites in six different orbital planes. The exact number of satellites varies as older satellites are retired and replaced. Operational since 1978 and globally available since 1994, GPS is the world's most utilized satellite navigation system.
GPS encodes this information into the navigation message and modulates it onto both the C/A and P(Y) ranging codes at 50 bit/s. The navigation message format described in this section is called LNAV data (for legacy navigation). The navigation message conveys information of three types: The GPS date and time, and the satellite's status.
Geocaching (/ ˈ dʒ iː oʊ k æ ʃ ɪ ŋ /, JEE-oh-KASH-ing) is an outdoor recreational activity, in which participants use a Global Positioning System (GPS) receiver or mobile device and other navigational techniques to hide and seek containers, called geocaches or caches, at specific locations marked by coordinates all over the world. [2]
GPS tracking may also be ordered for persons subject to a restraining order. [6] [7] Espionage/surveillance: a tracker on a person or vehicle allows movements to be tracked. Vehicle tracking: some people use GPS Trackers to monitor activity of their own vehicle, especially in the event of a vehicle being used by a friend or family member.
In astronomy and celestial navigation, an ephemeris (/ ɪ ˈ f ɛ m ər ɪ s /; pl. ephemerides / ˌ ɛ f ə ˈ m ɛr ɪ ˌ d iː z /; from Latin ephemeris 'diary', from Ancient Greek ἐφημερίς (ephēmerís) 'diary, journal') [1] [2] [3] is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position ...
GPS is widely used worldwide for civilian applications; Galileo's proponents argued that civil infrastructure, including aircraft navigation and landing, should not rely solely upon a system with this vulnerability.
Eratosthenes in the 3rd century BC first proposed a system of latitude and longitude for a map of the world. His prime meridian (line of longitude) passed through Alexandria and Rhodes, while his parallels (lines of latitude) were not regularly spaced, but passed through known locations, often at the expense of being straight lines. [1]