Internet service for tracking the moving object.

NAVSTAR GPS (born Navigation Satellite Time and Ranging, Global Positioning System - Measuring the distance and time of navigational satellites, Global Positioning System) - a satellite navigation system, often referred to as GPS. Allows you to any location (including the polar regions), almost any weather, as in outer space at a distance of up to 100 thousand kilometers from the Earth's surface, determine the location and speed of objects. The system is developed, operated and sees the U.S. Department of Defense (born US Department of Defense).

 

Space Segment

The basis of the system are the navigational satellites moving around the Earth to 6 circular orbital path (4 satellites in each), at an altitude of 20180 kilometers. The satellites emit signals in bands: L1 = 1575,42 MHz L2 = 1227,6 MHz, the latest model also L5 = 1176,4 MHz. Navigational information may be taken (in a direct line of sight of satellites) and processed using the GPS-receiver. Information in the C / A code (standard definition) transmitted through L1, is freely available, for free, without restrictions on use. Military applications (accuracy higher order) are provided by the encrypted P (Y) code. 24 satellites provide 100% of the system at any point on earth, but can not always provide stable reception and a good calculation of the position. Therefore, to increase the accuracy of the position and a provision for disabling the total number of satellites is supported in large amounts (~ 29 in 2006). The maximum number of simultaneously operating satellites in the NAVSTAR system is limited to 31.

 

GPS-Receivers

GPS-receiver - a device that determines the geographic coordinates of the point where he is currently based on data obtained from satellite radio groups NAVSTAR. Maximum measurement accuracy is 5-6 meters, if the correction signal from a ground station accuracy of better than 1 cm (differential method). Typical accuracy of commercial models navigators from 20-50 meters in the city to 3-10 meters in the open. There are GPS-monoblocks, with its own processor for the necessary calculations, and display for displaying information, and GPS-top boxes to PDAs and laptops. The latter is also known as GPS-armpits because of the close resemblance with computer mice. In addition to the latitude and longitude GPS-receiver is able to provide: * the exact time; * orientation to the cardinal points (in models without built-in compass - only when driving) * height above sea level (subject to receiving the signal from 4 or more satellites or in the presence of built-in altimeter) * direction to a point with coordinates given by the user; * distance traveled, average speed; * current position on electronic maps (some models). Information on ways to move (track) can be copied to a file, and then transferred (in particular, via the Internet) to other users of GPS, willing to go the same route. Using GPS-console displays information on your PDA, cell phone or computer that is connected to this console using the navigation software. Physical connection, usually via a serial port (COM-port, USB, Bluetooth). With regard GPS-receiver with a computer can be used by the manufacturer protocol receiver (Garmin, Magellan and others), but virtually all GPS-receivers support the exchange of information using a text protocol NMEA.