Can Global Positioning System (GPS) work in Nigeria? » Nigeria - Forum, Blogs, Free classifieds, Business Directory, Events, Polls
This is witchcraft! Or, how else would I describe a device that gives you the location and time information anywhere on or near the surface of the earth and in any weather? Without leaving your sitting room, but with the right gadget, you can literally monitor the physical events taking place anywhere on earth. When we talk of "everyday technology," this is it!
I am talking of a global positioning system (GPS). Like many advanced technologies, the internet included, GPS is a product of a research project funded by the United States Department of Defence. Global positioning system satellites evolved from a mission by the US for total earth surveillance for war and military purposes. Obviously this technology is dual-use, as a host of non-military applications have been spun-off. The technology is accessible by anyone with a GPS receiver and it is free!
However, you may not be getting the most precise and accurate signals, as those are reserved for the US military and select civilians. I am sure we are still happy with what we are getting, since the US government has spent billions of dollars developing and perfecting the GPS technology and all anyone has to pay for is the cost of his or her own GPS receiver gadget. For under $180, you can tap into this technology and obtain accurate enough data (latitude, longitude, altitude) of your location. You can also choose a location from a map, enter its grid numbers into your receiver, and obtain step-by-step directions to get to the location. For a non-technical introduction to the topic, you could consult the book "GPS for Everyone," which was written by L. Casey Larijani and published by American Interface Corporation, New York.
By Prof. Foluso Ladeinde
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Uche
#1
Yes, it can work if it is properly implemented. It has nothing to do with Nigeria, its more about proper implementation with the right equipment.
The Global Positioning System (GPS) is a network of about 30 satellites orbiting the Earth at an altitude of 20,000 km. The system was originally developed by the US government for military navigation but now anyone with a GPS device, be it a SatNav, mobile phone or handheld GPS unit, can receive the radio signals that the satellites broadcast.
Wherever you are on the planet, at least four GPS satellites are ‘visible’ at any time. Each one transmits information about its position and the current time at regular intervals. These signals, travelling at the speed of light, are intercepted by your GPS receiver, which calculates how far away each satellite is based on how long it took for the messages to arrive.
Once it has information on how far away at least three satellites are, your GPS receiver can pinpoint your location using a process called trilateration.
Trilateration
Imagine you are standing somewhere on Earth with three satellites in the sky above you. If you know how far away you are from satellite A, then you know you must be located somewhere on the red circle. If you do the same for satellites B and C, you can work out your location by seeing where the three circles intersect. This is just what your GPS receiver does, although it uses overlapping spheres rather than circles.
The more satellites there are above the horizon the more accurately your GPS unit can determine where you are.
GPS and Relativity
GPS satellites have atomic clocks on board to keep accurate time. General and Special Relativity however predict that differences will appear between these clocks and an identical clock on Earth.
General Relativity predicts that time will appear to run slower under stronger gravitational pull – the clocks on board the satellites will therefore seem to run faster than a clock on Earth.
Furthermore, Special Relativity predicts that because the satellites’ clocks are moving relative to a clock on Earth, they will appear to run slower.
The whole GPS network has to make allowances for these effects – proof that Relativity has a real impact.
Find related sites on relativity with physics.org
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