When discussing free space propagation we have not taken into account the presence of ground, mountains, buildings, seas, lakes, rivers, forests, and so forth. These should invariably be considered in the lowermost part of the atmo-sphere. Mostly 70% of the globe’s surface is covered with water. The electrical property of water is very much different from that of land and because of this, the propagation of electromagnetic waves will be affected in a different way. Even water is not always the same in that respect; the saline water of seas and oceans are unlike the fresh water of lakes and rivers. Moreover, in the absence of wind, the surface of water will behave like a smooth surface whereas a sea surface is mostly rippled. This phenomenon will also affect the propagation. Land also has a wide variety of states, such as damp soil and dry soil. Plains are also covered with bushes, forests, barren rocks, and mountains.