Atmospheric Attenuation

atmospheric attenuation

[¦at·mə¦sfir·ik ə‚ten·yə′wā·shən]
(geophysics)
A process in which the flux density of a parallel beam of energy decreases with increasing distance from the source as a result of absorption or scattering by the atmosphere.

Atmospheric Attenuation

 

a reduction in the intensity of electromagnetic radiation in the earth’s atmosphere as a result of the absorption and scattering of the radiation.

Solar radiation is absorbed primarily by water vapor and ozone and is scattered by molecules of air and aerosols. Scattering plays the main role in the atmospheric attenuation of solar radiation. The attenuation of long-wavelength terrestrial radiation from the earth’s surface, from the air, and from clouds also occurs in the atmosphere.

Atmospheric extinction, or the attenuation of starlight in the atmosphere, is especially important to take into account in astronomical observations. The intensity of atmospheric extinction depends both on the wavelength used for an observation and on the zenith distance of the celestial body being observed. The same celestial body appears three stellar magnitudes fainter at the horizon than at the zenith.

REFERENCES

Kondrat’ev, K. Ia. Luchistyi teploobmen v atmosfere. Leningrad, 1956.
Kondrat’ev, K. Ia. Aktinometriia. Leningrad, 1965.
References in periodicals archive ?
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In relation fog, rain, and haze are atmospheric attenuation it's important to be taken into account of FSO system.
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The atmospheric attenuation model describes the way light gets attenuated as it traverses from a scene point to the observer.
Such radars are also more resistant to atmospheric attenuation, a process by which a proportion of the radar's transmitted Radio Frequency (RF) energy is absorbed by moisture in the air.
Consequently the wireless industry is facing a crisis in its ability to keep up with the demand for backhaul capacity, and Janus AirDuplex provides a way to achieve higher throughput without resorting to using the millimetre-wave frequency bands above 42 GHz, offer broader bandwidths but suffer atmospheric attenuation and also often attract higher licensing fees.
Evaluation Based on CCDFs of Total Atmospheric Attenuation at 100 GHz and 300 GHz
T]), optical link range (R), and atmospheric attenuation coefficient ([alpha] in dB/km).
Take care if making observations, and follow all the solar observing protocols, even though the Sun will be low and have more atmospheric attenuation.
At 70 and 80 GHz, the atmospheric attenuation is not too much worse than at the popular microwave bands of 18 to 38 GHz.

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