Where in the world are
we? That has been a cry heard throughout history and really up
until just quite recently the response to this question has
been--Your guess is as good as mine!
This answer was not good enough for the US Department of
Defense. Subsequently, they came up with a technological
solution to this problem and called it the Global Positioning
System (GPS). It's based on a constellation of 24 satellites
orbiting the earth at a very high altitude.
The satellites are high enough that they are able to avoid
the problems encountered by land-based systems and they use
technology accurate enough to pin-point positions anywhere in
the world, 24 hours a day.
In actual use, people are getting measurement accuracies
better than the width of an average street, and in
"differential" mode surveyors are using GPS to make
measurements down to a centimetre. And since GPS was first and
foremost a defence system, it's been designed to be impervious
to jamming and interference.
What's most exciting about this new technology is its
potential. Today's integrated circuit technology has enabled
GPS receivers to be extremely compact and relatively
inexpensive. It won't be long before their increased use by
individuals parallels that of cellular phones. The
applications of GPS are almost limitless. Drivers will be able
to key in their destination and get a road map showing the
best route to use to get there. Similarly, with GPS and
tracking software the move-ment of vehicles and equipment can
be monitored with great accuracy.
GPS allows every square metre of the earth's surface to
have a unique address. Imagine a future when the Yellow Pages
is no longer a paper book but an electronic database that
includes the GPS location for each listing. So let's say
you're interested in going to a Chinese Restaurant-using the
database that calculates your location in relation to the
restaurant, your GPS unit will show you the best route to take
to get there. Real men don't eat quiche...and they don't get
lost.
