The effect of wavefront curvature on the coherence properties of laser light scattered by target centres in uniform motion

Moving speckle phenomena produced in the presence of wavefront curvature when laser light is scattered by an assembly of uniformly moving target centres are investigated. The first- and second-order space-time correlation functions of the scattered radiation are calculated and it is shown that the conditions for cross-spectral purity are not satisfied. It is pointed out that the effects offer a means of measurement of the velocity of the scatterers.