Above-water measurements of water-leaving radiance are widely used for water-quality monitoring and ocean-color satellite data validation. Reflected skylight in above-water radiometry needs to be accurately estimated prior to derivation of water-leaving radiance. Up-to-date methods to estimate reflection of diffuse skylight on rough sea surfaces are based on radiative transfer simulations and s...

We present a fast and compact representation of a skylight model for spherical harmonics lighting, especially for outdoor scenes. This representation allows dynamically changing the sun position and weather conditions on a per frame basis. We chose the most used model in real-time graphics, the Preetham skylight model, because it can deliver both realistic colors and dynamic range and its exten...

In a previous work [J. Opt. Soc. Am. A 24, 942-956 (2007)] we showed how to design an optimum multispectral system aimed at spectral recovery of skylight. Since high-resolution multispectral images of skylight could be interesting for many scientific disciplines, here we also propose a nonoptimum but much cheaper and faster approach to achieve this goal by using a trichromatic RGB charge-couple...

The Preetham skylight model is currently one of the most widely used analytic models of skylight luminance in computer graphics. Despite its widespread use, very little work has been carried out to verify the results generated by the model, both in terms of the luminance patterns it generates, and in terms of numerical reliability and stability. In this paper, we show where the model exhibits p...

A simple analytical model is presented for calculating the major features of the polarization of skylight over a hemisphere centered on an earthbound observer. The model brings together material from different topics in optics: polarization of plane waves, natural unpolarized light, and dipole scattering. Results calculated with the simple model are compared with experimental data. A brief desc...