A new Sky Scanner for sky luminance and radiance distribution

A clear-sky radiance archive from Meteosat ”water vapor” observations

Color and luminance asymmetries in the clear sky.

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. These analyses reconfirm our earlier measurements with narrow field-of-view spectroradiometers [J. Opt. So...

Ultraviolet Sky Radiance Distributions of Translucent Overcast Skies

The diffuse sky radiation component in the ultraviolet wavelengths is often at least 50% of the global irradiance under clear skies, and is the dominant component of ultraviolet global radiation under translucent overcast skies. The distribution of sky radiance was measured in a rural area and modeled for wavelength bands of ultraviolet-B (UVB, 280-320 nm) and ultraviolet-A (UVA, 320-400 nm). S...

A New Look at the Sky

X-ray astronomy, which in the last three decades has become one of the main tools for exploring the Universe, is presently receiving fresh stimulus from the ROSAT satellite observatory laun­ ched on 1 June 1990. The list of known cosmic X-ray sources includes almost all kinds of astronomical objects, ranging from the Sun and nearby stars out to qua­ sars at the edge of the known Universe. In ma...

ruby of the sky

in a profoundly impressive verse in shahnameh, sky is likened to red ruby. the present paper is attempted to probe into the background of the conventional belief regarding the relationship between sky and stone, for the semantic structure of the verse is composed in such a way that it is not possible to consider this relationship as being a conceptualistic viewpoint so that one may establish so...