Results 221 to 230 of about 601 (266)

Estimation of atmospheric aerosol refractive index

Atmospheric Environment (1967), 1980
Abstract A simple method is presented for estimating the refractive index, m of atmospheric aerosol from the measured volume scattering coefficient, b (480) and the particle size distribution, on the assumption that the Mie scattering theory is valid and that continental and urban aerosols can be described using a Junge-type power law distribution,
C.V. Mathai, A.W. Harrison
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Acoustic Sounding in a Refracting Atmosphere

The Journal of the Acoustical Society of America, 1972
Acoustic refraction by atmospheric wind and temperature inhomogeneities affects the measurements of acoustic sounders in four ways: (a) It displaces the location of the scattering volume relative to its apparent location based on straight-line ray paths.
T. M. Georges, S. F. Clifford
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World Maps of Atmospheric Refractivity Statistics

IEEE Transactions on Antennas and Propagation, 2014
Atmospheric refractivity and its vertical gradient affect electromagnetic wave propagation in the atmosphere. Consequently, their statistics are needed for propagation predictions. New world maps of refractivity and its vertical gradient statistics are derived from a global, long-term dataset of meteorological quantities as given by ERA-Interim ...
Martin Grabner, Vaclav Kvicera, Pavel Pechac, Milan Kvicera, Pavel Valtr, Antonio Martellucci   +5 more
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ATMOSPHERIC REFRACTION AND TEMPERATURE GRADIENT

The Canadian Surveyor, 1962
The coefficient of refraction is far from constant. It varies chiefly because of changes in the vertical temperature gradient of the atmosphere. From measurements of vertical angles between points of known heights, observed angles of refraction can be deduced.
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Infrared Refractive Index of Atmospheric Aerosol Substances

Applied Optics, 1972
The optical constants in the ir from lambda2.5 microm to 40 microm (4000-250 cm(-1)) of dry natural aerosol substances and of sea salt are presented. The aerosol substances were obtained from rain and snow water: dust and soot by sedimentation, and water soluble salts by evaporation.
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Anomalous Atmospheric Refraction at Sea

Nature, 1958
DURING the Atlantic crossing on Research Yacht Princess Waimai in 1954, to increase the accuracy of navigation astronomical sights were taken, as a rule, in series of observations: the noon sight series, extending usually for about an hour, with the Sun's culmination in its middle, 9 a.m. and 3 p.m. series, extending for about 20 min. Observations were
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Refraction and absorption in plasma atmospheres

Plasma Physics, 1983
Within the geometrical optics approximation the path of a ray in a plasma atmosphere is identical to the motion of a single particle under a potential of the same spatial variation as the electron density. The analogy may be used to construct the ray trajectories.
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Noise barriers in a refracting atmosphere

Applied Acoustics, 1996
Abstract A model is presented for the insertion loss of a noise barrier in a refracting atmosphere. The model is implemented in a prediction scheme for outdoor sound propagation up to ranges of 15 km. The accuracy of the model is demonstrated by comparison with numerical simulations of sound propagation over a barrier, using the parabolic-equation ...
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Geophysical Aspects of Atmospheric Refraction

1974
Abstract : The purpose of this paper is to discuss some of the geophysical aspects of atmospheric refraction and its effect on radars. Of special concern is the cause-and-effect relationships associated with the trapping of electromagnetic energy into atmospheric duct layers that result in anomalous propagation conditions and extend radar ranges far ...
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AN EMPIRICAL INVESTIGATION OF ATMOSPHERIC REFRACTION

Survey Review, 1958
AbstractIt is in general impossible to estimate with any accuracy the value of the coefficient of refraction to be used in reducing a measurement of angular altitude made to a distant hill top, or for that matter to a comparatively near object. The uncertainty may be of the order of 15%. Anything that can be done to improve this state of affairs should
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