Question

Is it necessary for the transmitting antenna and the receiving antenna to be of the same height for line of sight communication? Find an expression for maximum line of sight distance dm between these two antennas of heights h_T and h_R.

Answer 1

No, it is not necessary to have the same height.

For transmitting antenna of height h_r,

d_T is also called the radio horizon of the transmitting antenna.

The maximum line-of-sight distance d_m between the two antennae is

where h_R is the height of the receiving antenna

(c) Curiosity, power of observation.