Doppler shift can be used in an appropriate and precise satellite tracking technique. In the satellite communication, the Doppler shift will be much larger with the maximum Doppler considered in LTE specifications. Having the distance, its derivative and beacon signal frequency, Doppler curve can be estimated in each pass of the satellite. In satellite communication systems, due to relative motion between satellites and that between satellites and the ground, the resulting Doppler frequency. Then satellite distance to ground station and its changes in time is calculated via transformations of coordinate systems to each other. These Doppler shifts must be compensated for insatellite communications to deliver the most accurate andreliable services. Position of the satellite is firstly derived using equations governing on them and TLE which contains orbital elements and essential information in different coordinate systems such as ECI, ECEF and topocentric. A frequency Doppler shift (FDS) occurs when source of waves moves relative to an observer or viceversa, resulting in a change in frequency in relation to theobserver. In this paper, satellite distance and its derivative in time which is parameter in obtaining Doppler shift is derived. Spatially coherent communication, which requires a stable frequency difference, cannot compensate the random changes in frequency difference so that the. In low earth orbiting satellites, because of their low altitude to earth and their high rotation period around it, Doppler shift is appropriate to be used for tracking. For this purpose, a new orbit generator is presented for accurate simulation of satellite orbits. This paper analyzes Doppler frequency effects in various satellite orbits. One of its common applications in aerospace is its use in tracking satellites and orbit determination. One of the most important parameters in satellite communication links, particularly in low earth orbits (LEO) and elliptical orbits is Doppler frequency shift (DFS) and Doppler frequency rate (DFR) at communication channels. Doppler frequency shift which is defined as “the observed changes in frequency of transmitted waves when relative motion exists between the source of waves and an observer”, has wide applications in science, technology and different industries including communications, medicine, aerospace, electronics and etc. This chapter describes Doppler effect of artificial satellites. On the other hand, to compensate for the frequency offset induced by the satellite displacement relative to the GS, a means of Doppler shift is set up to indicate to the communication system the amount of frequency shift to introduce in order to maintain a proper communication link.
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