Atmospheric window

An atmospheric window is a region of the electromagnetic spectrum that can pass through the atmosphere of Earth. The optical, infrared and radio windows comprise the three main atmospheric windows. The windows provide direct channels for Earth's surface to receive electromagnetic energy from the Sun, and for thermal radiation from the surface to leave to space. Atmospheric windows are useful for astronomy, remote sensing, telecommunications and other science and technology applications. In the study of the greenhouse effect, the term atmospheric window may be limited to mean the infrared window, which is the primary escape route for a fraction of the thermal radiation emitted near the surface. In other fields of science and technology, such as radio astronomy and remote sensing, the term is used as a hypernym, covering the whole electromagnetic spectrum as in the present article.