Distinguish between 'sky wave' and ' space wave' modes of propagation. Why is the sky wave mode of propagation restricted to frequencies upto 40 MHz ?

Distinguish between .sky waves. and .space waves. modes of propagation in communication system. Why is sky wave mode propagation restricted to frequencies upto 40 MHz?

Distinguish between 'sky waves' and 'space waves' modes of propagation in communication system. (a) Why is sky wave mode propagation restricted to frequencies upto 40 MHz?

Distinguish between Sky wave and Space wave modes of propagation in a communication system.

Distinguish between Sky wave and Space wave modes of propagation in a communication system.

Distinguish between Sky wave and Space wave modes of propagation in a communication system.

What is sky wave communication Why is this mode of propagation restriced to the frequenceies only upto few MHz?