Modern Navigation Methods for Average Persons
Nowadays GPS (Global Positioning System) is a well known fact that has already become a norm of life for a great number of people. This system is made for ascertaining the position and velocity of the objects at any area on Earth. It can be done almost in all weather conditions and in all the areas on Earth including polar territory and in outer space to one hundred kilometers above Earth. Global Positioning System was developed and realized by the United States Department of Defense.
The basic principle of work is identifying of the location by the means of measuring the distance to an object from the spot with definite coordinates. The distance is counted by the delay time of radio signal diffusing from the sending satellite to the receiving of it by a GPS antenna. You may find that GPS receiver has to recognize the distance to three satellites and the time of the GPS system to detect 3-dimensional coordinates. As a result, radio signals from 4 satellites minimum are used for the detecting of GPS receiver's coordinates and altitude. Schriever base, Colorado is the control station that implements the orbital force supervision from Earth.
GPS receivers are frequently used today by civil people, sailors, rescuers and the police for position and speed definition of different objects. GPS systems are being traded in different stores and they are built in mobile phones, personal computers and onboarders. GPS receiver gives you a possibility to detect geographical coordinates of the receiver's position at the present moment. The accuracy of the definition of the signal location is from three to five meters and it is greatly improved with the correction radio signal from Earth and the calculating error is one millimeter.