András Barta

TL;DR: A combined radiometric and polarimetric algorithm is presented that performs the detection of clouds more efficiently and reliably as compared with an exclusively radiometric cloud-detection algorithm.

Abstract: Using 180° field of view (full-sky) imaging polarimetry, the patterns of the degree and angle of polarization of the moonlit clear night sky were measured in every half an hour throughout the night at full Moon. The patterns were compared with those of the sunlit sky. The observed patterns including the positions of the Arago and Babinet neutral points of the moonlit night sky and sunlit day sky are practically identical if the zenith angle of the Moon is the same as that of the sun. The possible biological relevance of the polarization pattern of the moonlit night sky in the polarization vision and orientation of night-active insects is briefly discussed.

TL;DR: It is shown by a model calculation that if the air layer between a cloud and a ground-based observer is partly sunlit, the degree of linear polarization p of skylight originating from the cloudy region is highest in the UV, because in this spectral range the unpolarized UV-deficient cloudlight dilutes least the polarized light scattered in the air beneath the cloud.

TL;DR: It is confirmed that Ephoron virgo is independently attracted to both unpolarized and polarized light sources, that both types of photopollution are being produced at the bridge, and that spatial patterns of swarming and oviposition are consistent with evolved behaviors being triggered maladaptively by these two types of light pollution.

TL;DR: It is shown that the fourth neutral point exists at the expected location and has characteristics similar to those of the Arago, Babinet, and Brewster points, and discussed why this anonymous "fourth" neutral point has not been observed in previous air- or space-borne polarimetric experiments.