Global
Positioning System (GPS): A Complete Review
by Tyson J Stevenson
The
system of knowing one's exact position on this earth
is known as the 'Global Positioning System'.
Precise positioning of any location can easily be done
with the help of this System. If anyone has a Global
Positioning System receiver and if the sky
remains clear then no one is going to be lost on this
Earth. The receiver is a pocket-sized gadget that makes
us inform about our exact position on this earth at
any moment. One thing is that this pocket-sized gadget
or receiver is very expensive and it also involves a
lot of technical ingenuity.
The
primary function of Global Positioning System is the
navigation in three dimensions. The Navigation receivers
are used for aircraft, ships, and ground vehicles and
sometimes it is also carried in hands by individual.
-
The working of the System
The
GP System provides some special satellite signals which
is processed in the receiver. These GPS receivers not
only track the exact location but can also compute velocity
and time. The positions can even be computed in three
dimensional views with the help of four GPS satellite
signals. The Space Segment of the Global Positioning
System consists of 27 Earth-orbiting GPS satellites.
There are 24 operational and 3 extra (in case one fails)
GPS satellites. These satellites move round the Earth
in 12 hours and send radio signals from space that is
being received by the GPS receiver.
The
control of the Positioning System consists of different
tracking stations that are located across the world.
These monitoring stations help in tracking signals from
those GPS satellites that are continuously orbiting
the earth. The Space Vehicles transmit microwave carrier
signals. The users of the Global Positioning System
have GPS receivers that can convert the satellite signals
by which one can estimate the actual position, velocity
and time. Four satellites are required to track the
three dimensional location and time.
The
operation of the system is based on a simple mathematical
principle called Trilateration. The Trilateration may
be of two types i.e. 2-D Trilateration and 3-D Trilateration.
In order to make the simple mathematical calculation
the GPS receiver should know two things. Firstly the
location of the place is to be traced by at least three
satellites above the place. Second is the distance between
the place and each of those Space Vehicles. Units those
have multiple receivers can pick up signals from several
GPS satellites at a same time. These radio waves are
electromagnetic energy that travels at the speed of
light.
-
Overview
GPS
is specially a Satellite Navigation System that helps
in tracking the exact location with the help of satellites.
The Global Positioning System is mainly
funded and controlled by the U.S Department of Defense
(DOD). The system was initially designed for the operation
of U. S. military. But today, there are also many civil
users of GPS across the whole world. The civil users
are allowed to use the Standard Positioning Service
without any kind of charge or restrictions.
Tyson
J Stevenson creates useful articles & reviews on
a wide variety of everyday subjects. Expect to see his
name often. View further samples of his work at Global
Positioning Systems at GPS
Info.
