Doppler shift in satellite communication7/24/2023 Doppler shift can be used in an appropriate and precise satellite tracking technique. Having the distance, its derivative and beacon signal frequency, Doppler curve can be estimated in each pass of the satellite. The high radial velocity of the satellite toward the receiver will cause a Doppler shift, and any change in that velocity caused by its orbit will cause that shift to change over time. We can perform this correction manually, but an automated system is preferable. Then satellite distance to ground station and its changes in time is calculated via transformations of coordinate systems to each other. the motion of the satellite with respect to the observer (Doppler shift). 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. In this paper, satellite distance and its derivative in time which is parameter in obtaining Doppler shift is derived. It was discovered by Christian Johann Doppler who described it as the process of increase or decrease of starlight that depends on the relative movement of the star. 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. A theoretical and experimental study of Doppler correction strategies for elliptical orbit satellite communications is presented. Definition: Doppler Effect refers to the change in wave frequency during the relative motion between a wave source and its observer. One of its common applications in aerospace is its use in tracking satellites and orbit determination. Generally, the higher the orbit, the lower the Doppler shift, and vice versa. 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. Doppler shift varies with the type and altitude of the satellite orbit.
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