atmospheric absorption

In telecommunications, atmospheric absorption refers to the loss of signal strength as electromagnetic waves travel through the Earth's atmosphere. This phenomenon is particularly significant for radio waves and optical signals at higher frequencies.12

Atmospheric absorption occurs when the transmitted frequency is close to the resonant frequencies of atmospheric gases like oxygen (O₂), water vapor (H₂O), and carbon dioxide (CO₂). These gases absorb energy from the signal, weakening it. While not a major issue for frequencies below 10 gigahertz, it becomes substantial at higher frequencies.12

Specific frequency bands, known as "windows," exist where atmospheric absorption is minimal, allowing for more efficient transmission. However, factors like rain, fog, and dust can also cause scattering, further degrading signal quality, especially in microwave and optical communication. This is a key consideration for satellite links, where signals must traverse the atmosphere to reach Earth terminals.123