What are ground waves?

Ground waves are a type of electromagnetic wave that propagates along the surface of the Earth. They are particularly effective at lower frequencies, such as those used in AM broadcasting, where the waves follow the contour of the terrain they travel over. This allows them to cover considerable distances by hugging the ground, thereby being less affected by obstacles and interference compared to higher frequency waves that might be reflected or refracted.

Ground waves occur primarily due to the interaction of the transmitted radio signal with the ground. The ground itself acts as a conductive medium, allowing the wave to propagate with less attenuation. This property is essential for providing reliable communication over longer distances, especially in rural or uneven landscapes where line-of-sight communication might be compromised.

Understanding ground waves is critical for amateur radio operators who aim to communicate effectively over varying distances and terrains.