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Global Positioning System: Difference between revisions
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*'''Aircraft passengers''' — Most [[airline]]s allow passenger use of GPS units on their flights, except during landing and take-off when other electronic devices are also restricted. Even though consumer GPS receivers have a minimal risk of interference, a few airlines disallow use of hand-held receivers during flight. Other airlines integrate aircraft tracking into the seat-back television entertainment system, available to all passengers even during takeoff and landing.<ref>Joe Mehaffey. [http://gpsinformation.net/airgps/gpsrfi.htm Is it Safe to use a handheld GPS Receiver on a Commercial Aircraft?]. Accessed [[May 15]], [[2006]].</ref> | *'''Aircraft passengers''' — Most [[airline]]s allow passenger use of GPS units on their flights, except during landing and take-off when other electronic devices are also restricted. Even though consumer GPS receivers have a minimal risk of interference, a few airlines disallow use of hand-held receivers during flight. Other airlines integrate aircraft tracking into the seat-back television entertainment system, available to all passengers even during takeoff and landing.<ref>Joe Mehaffey. [http://gpsinformation.net/airgps/gpsrfi.htm Is it Safe to use a handheld GPS Receiver on a Commercial Aircraft?]. Accessed [[May 15]], [[2006]].</ref> | ||
*'''Heading information''' — The GPS system can be used to determine heading information, even though it was not designed for this purpose. A "GPS compass" uses a pair of antennas separated by about 50 cm to detect the phase difference in the carrier signal from a particular GPS satellite.<ref>[http://www.jrcamerica.com/product.asp?Product_Id=17778 ''JLR-10 GPS Compass'']. Accessed Jan. 6, 2007.</ref> Given the positions of the satellite, the position of the antenna, and the phase difference, the orientation of the two antennas can be computed. More expensive GPS compass systems use three antennas in a triangle to get three separate readings with respect to each satellite. A GPS compass is not subject to | *'''Heading information''' — The GPS system can be used to determine heading information, even though it was not designed for this purpose. A "GPS compass" uses a pair of antennas separated by about 50 cm to detect the phase difference in the carrier signal from a particular GPS satellite.<ref>[http://www.jrcamerica.com/product.asp?Product_Id=17778 ''JLR-10 GPS Compass'']. Accessed Jan. 6, 2007.</ref> Given the positions of the satellite, the position of the antenna, and the phase difference, the orientation of the two antennas can be computed. More expensive GPS compass systems use three antennas in a triangle to get three separate readings with respect to each satellite. A GPS compass is not subject to magnetic declination as a magnetic compass is, and doesn't need to be reset periodically like a gyrocompass. It is, however, subject to multipath effects. | ||
*'''[[GPS tracking]]''' systems use GPS to determine the location of a vehicle, person, or pet and to record the position at regular intervals in order to create a log of movements. The data can be stored inside the unit, or sent to a remote computer by radio or cellular modem. Some systems allow the location to be viewed in [[real-time]] on the Internet with a web-browser. | *'''[[GPS tracking]]''' systems use GPS to determine the location of a vehicle, person, or pet and to record the position at regular intervals in order to create a log of movements. The data can be stored inside the unit, or sent to a remote computer by radio or cellular modem. Some systems allow the location to be viewed in [[real-time]] on the Internet with a web-browser. | ||