Ionosphere and radio communication

The Earth’s ionosphere consists of plasma produced by the photoionization of thin upper atmospheric gases by UV rays and photons of short wavelength from the sun. The upper ionosphere is used for radio communication and navigation as it re-ects long, medium, as well as short radio waves. Since solar radiation is the main cause of the existence of ionosphere, any variation in the radiations can affect the entire radio communication system. This article attempts to brie-y introduce the readers to the study of ionosphere in the context of its use as a radio re-ector, with particular reference to India. © 2017, Indian Academy of Sciences.