Vehicle navigation, tracking and management Team members: 1.Mr. Dautam Komar 2.Mr. Dorgaev Anvarsho 3.Mr. Saurabh Bhandari

Outline Topic purposes Basically problems in GNSS 3. Easy to use GNSS

What is Global Navigation Satellite System The satellite system of navigation (English Global Navigation Satellite Systems (GNSS)) the system intended for positioning (geographical coordinates) of land, water and air objects. The satellite systems of navigation also allow to get speeds and referrals of the movement of the receiver of a signal. Besides can be used for receiving the exact time. Such systems consist of the space equipment and a land segment (control systems). Now only two satellite systems provide a full and uninterrupted covering of the globe GPS and GLONASS. GPS (English Global Positioning System the system of global positioning, is read GPS) the satellite system of navigation providing measurement of distance, time and defining location in the world system of coordinates of WGS 84. Allows in any place of Earth (excepting subpolar areas), almost under any weather conditions and also in near-earth space to define location and speed of objects. The system is developed, realized and is operated by the U.S. Department of Defense, at the same time now is available to use for the civil purposes only the navigator or other device (for example, the smartphone) with the GPS receiver is necessary. Navigation- The word Navigation stems from the Latin word Navigare. It means To conduct a vehicle. In other words, it is the art of providing position to anyone in Land, Sea or Space. Man had been using different techniques of navigation from early ages. The most primitive method of navigation was Celestial Navigation i.e., observing stars, sun and moon. Ground based navigation used identified landmarks or maps. Gradually, with the growth of civilization and modern sciences, different instruments and methods came into the being. The initial instruments used for navigation were compass, lighthouse, quadrants, octants, etc.

How do we know this ? O bservations from various platforms are bias corrected and inter-calibrated to get the most likely state of the climate. Satellites are the most important part of the observation system, providing wide coverage, and representative set of observations. A. Observations

Basically problems in GNSS GPS is designed for open-sky applications and its coverage is often limited in many indoors and urban canyon areas. GPS receiver must lock onto the signal from at least four satellites then track them accurately. Radio frequency Interference is a major source for potential degradation of GPS accuracy and reliability. Other sources of error which degrades GPS accuracy and make RFI mitigation harder include satellite and user motions which introduce Doppler effects, slow power fluctuations (due to changes in effective antenna gain and path loss) and fast power changes (due to multipath fading, blocking and shadowing).

The principle of work of satellite systems of navigation is based on measurement of distance from the antenna on an object (which coordinates need to be received) to satellites which position is known with a big accuracy. The table of provisions of all satellites is called the almanac which any satellite receiver prior to measurements has to have. Usually the receiver keeps the almanac in memory since the last switching off and if he doesn't have become outdated instantly uses him. Each satellite transfers all almanac in the signal. Thus, knowing distances to several satellites of system, by means of usual geometrical constructions, on the basis of the almanac, it is possible to calculate the provision of an object in space. The method of measurement of distance from the satellite to the antenna of the receiver is based that the speed of distribution of radio waves is supposed known (actually this question extremely difficult, influences speed a set the slabopredskazuyemykh of factors, such as characteristics of an ionospheric layer and so forth). For implementation of a possibility of measurement of time of the extended radio signal each satellite of the navigation system radiates signals of the exact time, using the atomic clock which is precisely synchronized with system time. During the operation of the satellite receiver his hours are synchronized with system time, and at further reception of signals the delay between the radiation time which is contained in the signal and time of reception of a signal is calculated. Having this information, the navigation receiver calculates antenna coordinates. All other parameters of the movement (speed, a course, the passable distance) are calculated on the basis of measurement of time which an object has spent for movement between two or more points with certain coordinates.

Easy to use GNSS

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