Question

Describe radio wave propagation via Ground wave

Answer 1

Radiowaves in medium band of radio broadcast are generally propagated in the form of ground waves (also known as the surface waves). These waves travel along the surface of earth. For ground wave transmission the transmitting antenna and receiving antenna are close to the surface of earth. Being of long wavelength ($200$ m or more), these waves can easily bend along with earth's surface and propagate.

While progressing along the surface of earth, the ground waves induces current in the ground and bends round the corner of the objects on earth.The energy of ground waves is gradually absorbed by earth and the power of these ground waves decrease with distance from the transmitting station.This phenomena of loss of power is called attenuation.The attenuation of ground waves increases rapidly with the increase in its frequency.

For ground wave propagation, the maximum coverage range depends upon : transmitting power and frequency of signal wave.The ground wave propagation is useful for low frequency signal waves , for short distances. Ground wave communication is not suited for high frequency signal wave and for long range communication.It is generally used for local broadcasting .