New Rayleigh-scattering optical thickness values for the terrestrial atmosphere in the 260 < lambda < 1500-nm wavelength range have been calculated using updated data on atmospheric optical parameters. The calculations include molecular scattering from water vapor and take into account varying atmospheric composition with altitude. The new Rayleigh-scattering coefficients average 4.5% lower tha...

Rayleigh scattering from neutral hydrogen during and shortly after recombination causes the CMB anisotropies to be significantly frequency dependent at high frequencies. This may be detectable with Planck, and would be a strong signal in any future space-based CMB missions. The later peak of the Rayleigh visibility compared to Thomson scattering gives an increased large-scale CMB polarization s...

Rayleigh scattering has been shown to be a useful diagnostic technique for two-dimensional imaging studies of reacting and non-reacting flows. For example, by combining Rayleigh scattering with a simultaneous measurement of the fuel concentration (e.g., using Raman scattering), mixture fraction and temperature can be determined in flames. In this work, it is demonstrated that the fuel concentra...

Rayleigh scattering is used frequently in Monte Carlo simulation of multiple scattering. The Rayleigh phase function is quite simple, and one might expect that it should be simple to importance sample it efficiently. However, there seems to be no one good way of sampling it in the literature. This paper provides the details of several different techniques for importance sampling the Rayleigh ph...

Light scattering effects can be noticed every day when we look at the sky or the atmosphere. The main reason why the sky is blue on a sunny day is Rayleigh scattering (after Lord Rayleigh) of sunlight, i.e., the scattering of electromagnetic radiation by particles much smaller than the wavelength. However, for cloud and haze scattering, the Mie theory (after Gustav Mie) is very important where ...

Knowledge about Rayleigh scattering cross sections is relevant to predictions about radiative transfer in the atmosphere, and needed to calibrate the reflectivity of mirrors that are used in high-finesse optical cavities to measure atmospheric trace gases and aerosols. In this work we have measured the absolute Rayleigh scattering cross-section of nitrogen at 405.8 and 532.2 nm using cavity rin...

Compton scattering models in Geant4 are the following: a.) G4ComptonScattering: listed as ”compt” in the process name. No Rayleigh scattering in the model. b.) G4LowEnergyCompton: Process name is ”LowEnCompton” in the tracking code. It has errors in the treatment of Rayleigh scattering and does not account for Doppler broadening (the effect of bound electron momentum on the scattered particle e...

Using a frequency-doubled Nd-YAG pulsed laser and a single-intensified CCD camera, Rayleigh scattering measurements have been performed to study the cluster formation in a Mach 6 wind tunnel at NASA Langley Research Center. These studies were conducted both in the free stream and in a model flow field for various flow conditions to gain an understanding of the dependence of the Rayleigh scatter...