Glare points

Abstract

Glare points are the intensity maxima seen when a water drop illuminated by a wide beam is viewed from a certain direction and imaged. We show that good resolution in both the scattering angle and the glare point position can be achieved only if the size parameter x = 2pia/lambda is >>1 and that the positions of the glare points can be computed by a Fourier transform from the familiar Lorenz-Mie scattering function. Sample computations made with x = 10,000 and x = 20,000 are presented. Glare points corresponding to rays that have suffered as many as 15 internal reflections can be identified, in agreement with experimental findings.