What type of propagation is necessary for communication with satellites?

Line of Sight propagation is essential for communication with satellites because it allows for a direct path between the transmitter (on the ground) and the satellite (in orbit). This direct pathway ensures that signals can be transmitted and received without significant obstruction or interference.

Satellites generally operate at high altitudes, and their communication relies on this line of sight to effectively transmit radiofrequency signals. Since satellites are positioned far above the Earth, it is crucial for any communication signal to travel directly to and from these satellites without being obstructed by the curvature of the Earth or other physical barriers. In practical terms, ground-based antennas must be aligned directly towards the satellite to maintain optimum signal strength and clarity.

Other types of propagation, such as Ground Wave and Non-Line of Sight, are not suitable for satellite communication due to their inherent limitations, such as reliance on terrestrial features or obstructions, which would hinder the effectiveness of signals meant to reach space-based satellites. Local Wave is not a recognized propagation type relevant to satellite communication. Hence, the selection of Line of Sight is accurate in identifying the necessary condition for effective satellite communication.