ATMOSPHERIC RADIATION FROM CLOUDY SKY

An efficient method for computing atmospheric radiances in clear-sky and cloudy conditions

A computationally efficient method is developed to simulate the radiances in a scattering and absorbing atmosphere along an arbitrary path in the spectral region ranging from visible to far-infrared with a spectral resolution of 1 cm. For a given spectral region, the method is based on fitting radiances pre-calculated from the discrete ordinate radiative transfer (DISORT) at several wavenumbers...

Fast Forward Modelling of Cloudy Atmospheric States

Cloud detection always relies on some knowledge of how clear and cloudy observations will differ. In a full Bayesian determination of the probability that an infrared image pixel contains cloud, an estimate of the brightness temperature distribution for clear and cloudy cases is required. A method for estimating this distribution for cloudy atmospheric states through exploitation of the knowled...

Digital all-sky polarization imaging of partly cloudy skies.

Clouds reduce the degree of linear polarization (DOLP) of skylight relative to that of a clear sky. Even thin subvisual clouds in the "twilight zone" between clouds and aerosols produce a drop in skylight DOLP long before clouds become visible in the sky. In contrast, the angle of polarization (AOP) of light scattered by a cloud in a partly cloudy sky remains the same as in the clear sky for mo...

SHDOMPPDA: A Radiative Transfer Model for Cloudy Sky Data Assimilation

The spherical harmonics discrete ordinate method for plane-parallel data assimilation (SHDOMPPDA) model is an unpolarized plane-parallel radiative transfer forward model, with corresponding tangent linear and adjoint models, suitable for use in assimilating cloudy sky visible and infrared radiances. It is derived from the spherical harmonics discrete ordinate method plane-parallel (SHDOMPP, als...

Cloudy Sky Velocity Map Based on Matched Filter