Global Positioning System is a really famous navigation facilities that are applied by a great number of people nowadays. The aim of this arrangement is the defining of the velocity and position of the objects. It can detect the object at any place on Earth, even in polar territories and in outer space to 100 kilometers above Earth in any weather conditions. Global Positioning System was worked out and accomplished by the United States Department of Defense.

The basic principle of functioning is definition of the position by the method of measuring the distance to an object from the spot with fixed coordinates. The distance is defined by the counting the delay time of the signal sending from the satellite-transmitter to a GPS antenna which is a receiver. You may find that GPS receiver has to know the distance to three satellites and the time of the GPS system to identify 3-D coordinates. And to detect GPS receiver's coordinates and altitude it has to apply minimum 4 satellites' signals. Orbital force tracking is realized from the main control station that is located in Schriever base, Colorado.

A great amount of civil persons as well as the police, sailors and rescuers use Global Positioning System for various needs, mostly for navigation, location and speed definition. Handheld GPS systems are being sold in different shops and they are built in cell-phones, PCs and onboarders. A user may detect his geographical position with the help of GPS receiver at any moment of time that he needs. The exactness of the location definition is from 3 to 5 meters and when radio signal is improved from Earth it becomes better and may be to 1 millimeter.

You may get GPS mapping software as well. Such system gives you an opportunity to detect your geographical position on the electronic map.

There are two kinds of maps. Raster electronic maps are connected with the first type of maps that are the simplest and the most available. It is the image of an area where the position if the receiver is used. The scale of such an electronic map depends on the initial version of it. This electronic map may be a simple photo from space or a scanned paper map.

And vector maps are made with their proper database within that makes them very helpful. There are all information about surrounding objects, the place you are situated in and other useful information for a traveler. For example the country information includes the rivers, lakes, mountains and other objects that are situated in this territory. These 2 kinds of electronic maps contain the information about all the hotels, motels, cafes and filling stations in your place of location. So you may buy also portable GPS that will give you a convenience during the trip.

But we have to say some words about the shortcomings of this produce. The basic disadvantage is that GPS is radio-navigation arrangement and due to it radio signal may not be received in some circumstances. So if you are in a reinforced concrete building it is almost impossible to identify your location. But anyway it is the best system of defining your geographical coordinates for today.