Question

Explain space wave propagation of radio waves .

Answer 1

$\underline{\mathfrak{Answer}}$

✨The propagation of very high frequency (VHF), ultra high frequency (UHF) and microwave is not possible through ground waves and sky waves because these waves are almost absorbed by the surface of earth after travelling a small distance. Also ionosphere cannot reflect these waves back to earth.$\bold{Therefore}$ , these high frequency waves (above 30 MHz) called space waves can be transmitted from transmitting antenna to receiving antenna through a mode known as $\bold{space\: wave\: propagation}$ .

This mode of propagation is limited to the line of sight i.e., these waves can be transmitted if there is no obstruction (like high building, mountains, curvature of earth etc.) in between the transmitting and receiving antenna.

Therefore ,transmission of space waves is not possible beyond horizon. Transmission of these waves is also possible due to their refraction in troposphere. The transmitted space waves suffer refraction in the troposphere and bend slowly towards the earth's surface. Due to this $\bold{refraction}$, the line of sight distance is increased. The waves can be transmitted without losses in air only if the receiving antenna directly intercepts the signals from the transmitting antenna.

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$\underline{\mathfrak{hope\: it\: helps}}$