The Earth's atmosphere as it relates to wireless communication.

Author：admin  Clicks：32  Release time：2025-12-19

Electromagnetic wave propagation in wireless communication involves the Earth's atmosphere. This section mainly introduces the relevant knowledge of the Earth's atmosphere.The structure of the Earth's atmosphere is shown in Figure 1-1. The lowest layer of the Earth's atmosphere is the troposphere, with an average thickness of about 10 to 20 kilometers. Because it is close to the Earth's surface, the temperature of the atmosphere decreases as the altitude increases, and air convection is very frequent. The name "convection" is based on the "violent air convection". The average height of the troposphere varies with geographic region, ranging from 10 to 12 kilometers in temperate regions and 16 to 18 kilometers near the equator. The troposphere concentrates more than 90% of the water vapor in the atmosphere and more than 3/4 of the atmospheric mass.The layer above the troposphere is the stratosphere, also known as the isothermal layer, which is about 20 to 40 kilometers above the ground. Above the stratosphere is the ionosphere.
The ionosphere is a part of the Earth's atmosphere. At this altitude, atmospheric convection is minimal. Under the influence of solar radiation and cosmic rays, ionization occurs, forming a considerable number of ions and free electrons. According to the height from the Earth's surface, the ionosphere is divided into four layers: the D layer, E layer, F1 layer, and F2 layer, as shown in Figure 1-2. During the day, all four ionospheric layers exist; at night, the D layer disappears, and the F1 and F2 layers merge into one layer (still referred to as the F2 layer).