Question

For space wave propagation derive los distance I.eD=4.123(✓ht+✓hr)

Answer 1

Answer:

When a wave propagates in a straight line, from the transmitting antenna to the receiving antenna, its 'mode of propagation' is called space wave communication. 

 Space waves are used for the Line of Sight (LOS) communication. Space wave communication involves the  transmission from transmitter, traveling along a straight line in space, reaches to receiving antenna.   The range of their frequencies is 40 MHz and above. The range of space wave propagation is limited by line  of sight distance between transmission to receiver /repeater antenna. 

From figure, the range of antenna PC is PA.

Using Pythagoras theorem

(R+h)2=PA2+R2

⟹PA=h2+2Rh

≈2Rh(h<<R)