Atmospheric Noise


Also found in: Wikipedia.

atmospheric noise

[¦at·mə¦sfir·ik ′nȯiz]
(electronics)
Noise heard during radio reception due to atmospheric interference.

Noise, Atmospheric

 

electrical fluctuations in a receiving antenna caused by the heat radiation of the earth’s atmosphere in the radio spectrum (seeFLUCTUATIONS, ELECTRICAL).

Atmospheric noise worsens the quality of radio reception by engendering acoustical noise and false signals and decreasing measurement accuracy. A quantitative characterization of atmospheric noise is provided by noise temperature, which is equal to the product of the average physical temperature of the atmosphere (≈300°K) and the coefficient of absorption of the atmosphere. The latter depends on the state of the atmosphere (humidity, dust content, and the like), the shape of the antenna radiation pattern, the working length of the wave λ, and the orientation of the antenna in space. Ordinarily, when λ > 10 cm and altitudes of the main lobe of the radiation pattern are more than 20°, atmospheric noise is negligibly small.

References in periodicals archive ?
The procedures to generate TRNGs often measure a random physical occurrence, such as radioactive decay or atmospheric noise, although the use of dice or coin flipping is still used.
However, it has begun experimenting with long-range facial imagery under an Army contract with Securics, a company focused on eliminating the effects of atmospheric noise.
The rest of the package strikes all the right notes, with stunning visuals and perfect atmospheric noise.
org, uses a radio to pull random numbers out of the atmospheric noise generated by weather systems.
With original music by Dusty Trails that included samba, atmospheric noise, and text with a slight delay, like a mirror reflection, the hour-long dance was utterly engaging.
The SteelSeries Siberia v2 Counter-Strike: Global Offensive Headset isolates atmospheric noise with sound-dampening foam and leather ear cushions, while its over-the-head suspension design makes the headset comfortable and lightweight.
Placed in an aluminum-lined pit to reduce spurious radio emissions from the ground and from the radio telescope itself, the entire device rotates on a turntable to scan different parts of the sky, The interferometer eliminates most atmospheric noise, since such random fluctuations are washed out when the signals from the three antennas are combined, Duffett-Smith says.
It also gets the excitement of the game across with a soundtrack full of atmospheric noises, such as the exhilarating roar of the crowd when a 'Breakaway' goal is scored.

Full browser ?