Global Positioning System, GPS in short, is a satellite assisted navigation system providing location and time information anywhere on the Earth.

1. GPS Navigation – How the System Functions?
Global Positioning System, GPS in short, is a satellite assisted navigation system providing
location and time information anywhere on the Earth. GPS navigation is possible only when the
GPS system installed in the vehicle has unobstructed line of sight to a minimum of four GPS
satellites in the space. The facility is maintained by US government and is free of cost.
The position of the vehicle fitted with GPS is accurately calculated by the signals sent by the
GPS satellites. Each of these satellites independently transmits signals continuously about the
time the message was sent and the position of the satellite at the time the message was
transmitted. In turn, with the help of Trilateration or any other suitable algorithm, the receiver
determines the exact location of the vehicle by considering the time elapsed in transit coupled
with the satellites' location. The location is displayed on a digital display device.
There are three major segments in the GPS, of which two are controlled by US Air Force -the
space segment and the control segment; while the third one is the user segment. The space
segment consists of twenty four to thirty two satellites. The control segment consists of a master
control station, monitor stations and several dedicated antennas. The user segment is the GPS
navigation device. The positioning is so accurate that depending on the model of GPS used, the
deviation will not be more than twelve yards. Accurate synchronization of the atomic clocks in
the GPS system is responsible for its precision of the system.
A GPS has additional features like maps in human readable format, provides suggested
directions to drivers through text or speech, providing information of traffic conditions coupled
with suggesting alternate routes.
While GPS assists drivers with information about location and direction, a car security system
makes sure the car is not stolen or damaged. Present day high end cars are factory fitted with
these security features. This may be a simple alarm sound when unauthorised persons try to open
the car door or it may be an immobilizer where the car engine will not start when an
unauthorised person uses the ignition key. Even keyless remote entry has been made possible
where in the car security system recognizes the approach of the authorised person near the car
and allows the person to open the door; otherwise the door will not open.
When it comes to in car entertainment, the best is an audio system. If the person has the expertise
car audio installation can be done without any professional help. For this one should have the
basic knowledge of connecting and positioning of the speakers with associated wiring. There are
many websites that give step by step instructions on how to proceed with car audio installation.
One of the best portable audio systems is the iPod. One can integrate iPod with the car's audio
system. iPod car installation requires some amount of technical expertise and if one is not
confident then it is best left to a professional. There are kits available in the market to assist one
with iPod car installation.
Author's info: A car's GPS navigation system helps drivers find direction while driving. In car
entertainment requires car audio installation at the minimum. Advanced entertainment requires
iPod car installation so that one can listen to music uninterrupted. When it comes to passenger
entertainment, a car TV installation is an essential accessory. All car accessories are available
at http://www.motormusiccarstereo.com/.