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Distinguish between sky waveand space wave modes of communication. What is the main limitation of space wave mode? Writethe expression for the optimum separation between the transmitting and receiving antenna for effective reception of signals in this mode of communication. |
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Answer» Solution :The ratio wavesare reflectedback to the earth by the ionosphere are known as sky waves and the mode in which sky waves travel is CALLED sky wave propagation. High frequency waves above 40Hz called space waves can be transmittedfrom transmitting antenna to receiving antaena and the mode of travelling of these wave through space is called space wave propagation. Space wave propagation cannot cover global transmission DUE to inability of installation of repeaters ( LOS is obstructed) as mountains and oceans STOPS LOS communication. If `h_(1)` is the height of antaena (transmitting ) and hr height of receiving antaena the MAXIMUM LOS distance `d_(1)= d_(1) + d_(2) = sqrt(2hR) + sqrt(2Rh_(r))`. |
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