title: Color and luminance asymmetries in the clear sky.
abstract: 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. Soc. Am. A 18, 1325 (2001)], and they do so with much higher temporal and angular resolution across the entire sky dome.
authors.affiliation: Departamento de Optica, Facultad de Ciencias, Universidad de Granada, Granada 18071, Spain. javierha@ugr.es
authors.forename: Javier
authors.initials: J
authors.lastname: Hernández-Andrés
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Lee
authors.forename: Javier
authors.initials: J
authors.lastname: Romero