- Global Positioning System
GPS is the shortened form of NAVSTAR GPS. This is an acronym for
NAVigation System with Time And Ranging Global Positioning System.
GPS is a solution for one of man's longest and most troublesome
problems. It provides an answer to the question 'Where on earth
am I ?'
One can imagine that this is an easy question to answer. You can
easily locate yourself by looking at objects that surround you and
position yourself relative to them. But what if you have no objects
around you ? What if you are in the middle of the desert or in the
middle of the ocean ? For many centuries, this problem was solved
by using the sun and stars to navigate. Also, on land, surveyors
and explorers used familiar reference points from which to base
their measurements or find their way. These methods worked well
within certain boundaries. Sun and stars cannot be seen when it
is cloudy. Also, even with the most precise measurements position
cannot be determined very accurately.
At the beginning of the 1970s, a new project was proposed - GPS.
This concept promised to fulfill all the requirements of the US
government, namely that one should be able to determine ones position
accurately, at any point on the earth's surface, at any time, in
any weather conditions.
GPS is a satellite-based system that uses a constellation of 24
satellites to give a user an accurate position.
GPS Basics Introduction to GPS
by Leica Geosystems Inc.
"A system of satellites and receiving devices used to compute
positions on the Earth. GPS is used in navigation, and its precision
supports cadastral surveying".
Excerpted from Glossary of GIS Terms in
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