ON THE SCATTERING OF LIGHT BY THE FOG
Yoshio Arai, Minoru Taketomi · JOURNAL OF THE ILLUMINATING ENGINEERING INSTITUTE OF JAPAN · 1951
The authors introduced a theoretical equation (13) to complete the brightness distribution of halo around the light located in fog. And it was confirmed by authors' experimental results that the application of this equation was sufficiently satisfactory for the practical use.In this case, the relative position of the light and observer was shown in Fig. 1. In the course of derivation of the equation (13), the principal assumption was that the effects of the distribution of wavelength of light and the size or number of fog-droppets were excluded. The main result of this report is as fullows:(1) The brightness of halo is inversely proportional to distance (γ0) between the light and the observer, and is linearly proportional to the beam angle of light when the beam angngle is less than 40 degrees.(2) In case the light and the distance detween the light and the observer are constant, the brightness of halo is maximum when β=1/γ0, where β is a attennuation coefficient in fog.