question_answer 35)

  A 50 MHz sky wave takes 4*04 ms to reach a receiver via re-transmission from a satellite 600 km above earth's surface. Assuming re-transmission time by satellite negligible, find the distance between source and receiver. If communication between the two was to be done by Line of Sight (LOS) method, what should size and placement of receiving and transmitting antenna be ?

Answer:

                   Here, total time taken Let x be the distance of satellite from the surface of earth. Let T be the source of em wave (i.e., transmitter), R be receiver and S be satellite at locations shown in Pig. 10 (EP).5. Or      Distance between source and receiver = 2 d = 2 x 85.06  170 km For the line of sight communication, let S be the source of em wave, R be receiver and ht, be the size of antenna used. The maximum distance covered on ground from the transmitter by the emitted em waves is