The results of a series of systematic measurements of skylight polarization are presented and discussed. The measurements were made at Los Angeles during spring, 1963. A photoelectric skylight polarimeter employing ac light modulation has been employed in these measurements which were confined to the plane of the sun’s vertical. Three spectral intervals (bandwidth̃150 Å) centered around 4000, 5100, and 6000 Å were studied. An attempt has been made to account for the departure of location and dispersion of the neutral points and the polarization maximum from the computed values for a purely molecular atmosphere in terms of the local turbidity. The effect of the variable reflectance of the ground on the magnitude of the polarization maxima has been included in these studies.
GEORGE C. HOLZWORTH and C. R. NAGARAJA RAO, "Studies of Skylight Polarization," J. Opt. Soc. Am. 55, 403-408 (1965)