Which propagation method involves direct line-of-sight transmission between transmitter and receiver?

Which propagation method involves direct line-of-sight transmission between transmitter and receiver?

• A. Direct - LOS
• B. Surface
• C. Sky Waves
• D. Troposcatter

Answer: (A)

Line-of-sight propagation means the signal travels straight from transmitter to receiver with no obstructions in between. This requires that the two points sit within each other’s horizon, which is usually achieved by raising the antennas high enough to clear the Earth's curvature and any terrain or buildings. Because the path is direct, the signal doesn’t rely on bouncing off the ground or ionospheric layers or on atmospheric scattering, which is why this method is typical for VHF, UHF, and microwave communications. Other methods involve surface waves along the ground, ionospheric reflection to reach beyond the horizon, or scattering in the troposphere, none of which use a direct line-of-sight path. Direct line-of-sight is the method described.

Line-of-sight propagation means the signal travels straight from transmitter to receiver with no obstructions in between. This requires that the two points sit within each other’s horizon, which is usually achieved by raising the antennas high enough to clear the Earth's curvature and any terrain or buildings. Because the path is direct, the signal doesn’t rely on bouncing off the ground or ionospheric layers or on atmospheric scattering, which is why this method is typical for VHF, UHF, and microwave communications. Other methods involve surface waves along the ground, ionospheric reflection to reach beyond the horizon, or scattering in the troposphere, none of which use a direct line-of-sight path. Direct line-of-sight is the method described.