Satellite Navigation systems offer geo-spatial positioning with wide global coverage. Scientifically known as Global Navigation Satellite System (GNSS), it ensures electronic receivers to inform about the longitude, latitude and altitude of the users. It tells you about the exact location where you are standing at that particular time. This is done with the time signals which are generally transmitted by satellite radios.

 

The NAVSTAR Global Positioning System by the United States is the only operational GNSS right now. Russia is also marking its entry in the field with GLONASS. Galileo positioning system is scheduled to be operational by 2010. It is said to be the next generation GNSS by European Union.

The first Sat Nav device was installed by the US defense forces. Earlier, it was mainly used in the military applications but now they are used as car accessories and come pre-loaded with mobile phones. They broadcast the signal that informs about the position of the satellite and at the same time records the time of the transmitted signal. This detail is transmitted in a data format and is applied as code i.e. the time reference. They are now used with great ease and simplicity. Mostly used in cars, they are recognised as personal travel assistants.

They come with user-friendly features like turn-by-turn voice directions and highlighted points of interest, for example, petrol pumps, ATMs and restaurants. To avoid any error related to position, time and velocity, the satellite navigation receivers use Kalman filtering techniques. The sat Nav enabled devices are advantageous. They are used for varied navigational purposes like searching, surveying and in the field of geophysical sciences. Different well known brands such as Road Angel, Garmin and TomTom have introduced latest sat Nav gadgets with customer-friendly menus; wide touch screens and safety camera locations. These devices are helping in precise mapping of locations.

Raina Kelsey is an expert author, and writes about latest gadgets.
Sat Nav Devices
TomTom Go 720
Garmin Nuvi 300