Explain sky wave propagation of radiowaves.

Explanation

Sky wave propagation: The communication process in which the propagation of waves from transmitting antenna to the receiving antenna takes place after reflection from the ionosphere, is known as sky wave propagation. The upper part of the atmosphere is known as ionosphere in which lot of free electrons are available. The layer extending from 90 km to 140 km is known as

Kennelly Heaviside layer (Elayer). The layer above Elayer where concentration of electrons is comparably less is known as appleton layer (F layer). The radio waves whose frequency is between 2 MHz to 10 MHz are reflected by the ionosphere. The radio waves whose frequency exceeds 10 MHz penetrates the ionosphere and never returns to the earth surface. This mode of transmission is used for very long distance transmission.