Results 221 to 230 of about 29,986 (258)

A Clear Sky Model of Diffuse Sky Radiance

Journal of Solar Energy Engineering, 1987
A model, previously proposed, describing the sky radiance as a continuous function, has been calibrated from 11,000 individual measurements made in scans taken across springtime skies in Toronto using a narrow field of view radiometer. The model reproduces the measured sky radiance with a mean bias error under five percent and a root mean square error ...
F. C. Hooper, A. P. Brunger, C. S. Chan
openaire   +1 more source

Color and luminance asymmetries in the clear sky

Applied Optics, 2003
A long-standing assumption about the clear sky is that its colors and luminances are distributed symmetrically about the principal plane. As useful as this approximation is, our digital-image analyses show that clear-sky color and luminance routinely depart perceptibly from exact symmetry.
Javier, Hernández-Andrés, Raymond L, Lee, Javier, Romero   +2 more
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Digital imaging of clear-sky polarization

Applied Optics, 1998
If digital images of clear daytime or twilight skies are acquired through a linear polarizing filter, they can be combined to produce high-resolution maps of skylight polarization. Here polarization P and normalized Stokes parameter Q are measured near sunset at one inland and two coastal sites.
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Apparent Clearing of the Sky at Dusk

Nature, 1945
CLOUDS may disappear by evaporation of the droplets, a purely physical effect, but they may also vanish to the eye, though in fact they remain. It is generally accepted that the eye can distinguish between brightnesses down to the limit of 2 per cent difference, which may be termed the discrimination factor.
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Nice colors and a clear sky

Acta Obstetricia et Gynecologica Scandinavica, 2011
Torbjørn Moe, Eggebø, Reynir Tómas, Geirsson   +1 more
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Worldwide performance assessment of 95 direct and diffuse clear-sky irradiance models using principal component analysis

Renewable and Sustainable Energy Reviews, 2021
Jamie M Bright, Chris Gueymard, Xixi Sun   +2 more
exaly  

Thunderbolt from a Clear Sky

2018
This chapter deals with the outbreak of war in 1914, which exposed the poor quality and high geographical concentration of the acceptance business of some firms. The inconsistent and, in some cases, inequitable treatment of firms of foreign origin by the City establishment is examined.
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Measuring the Clearness of the Sky

Scientific American, 1872
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Out of a clear sky…

New Scientist, 2014
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Identification of periods of clear sky irradiance in time series of GHI measurements

Renewable Energy, 2016
Clifford Hansen, Matthew J Reno
exaly