What Is Gps - Pioneer AVIC-505 Owner's Manual

What is GPS?

The global positioning system, or GPS, depends on a network of artificial satellites encircling
the earth. Each of the 24 satellites, which orbit at a height of 21,000 km, continually broadcasts
radio signals giving time and position information. This ensures that signals from at least three
can be picked up from any open area on the earth's surface.
GPS signals can be freely picked up by anyone with the appropriate equipment. By applying
sophisticated signal processing techniques to the data received, it is possible to determine a
location to within a few tens of metres. Advances in electronics mean that the computing power
needed to do this signal processing is easily fitted into aircraft, boats, and now even navigation
systems for vehicles.
How is it used?
GPS is used by this system to determine the absolute location of your vehicle. This enables it
to display your location accurately on a map. The accuracy of the information obtained with
GPS depends on how good the reception is. When the signals are strong and reception is good,
it is possible to determine latitude, longitude, and altitude for accurate positioning in three
dimensions (3D). On the other hand, if signal quality is low, only two dimensions (2D), latitude
and longitude, can be obtained and positioning errors are somewhat greater.
• The GPS satellites are administered by the United States Department of Defence; on occasion, the
data broadcast by the satellites may intentionally be reduced in quality. In such a case, positioning
errors will increase.