Which factor does NOT affect ground wave propagation?

Ground wave propagation refers to the transmission of radio waves along the surface of the Earth. This type of propagation is influenced by various factors that can either enhance or hinder signal strength and coverage.

High altitude does not significantly impact ground wave propagation. Ground waves travel along the surface of the Earth, and their characteristics are primarily dictated by the properties of the ground and atmospheric conditions near the surface. When operating at high altitudes, there may be variations in signal coverage, but it is not as directly related to the propagation of ground waves, which are more concerned with the immediate surface environment.

In contrast, dense vegetation, mountainous terrain, and severe weather conditions can all create physical obstructions or changes in the environment that affect how well the ground wave signal can propagate. For instance, dense vegetation can absorb and scatter radio waves, mountainous terrain can block or reflect signals, and severe weather can introduce atmospheric variations that alter propagation characteristics. Therefore, understanding that high altitude is less of a direct factor in ground wave propagation helps clarify the concept effectively.