Coherence theory predicts that the correlation in the fluctuations of a sou
rce distribution can cause frequency shifts in the spectrum of the emitted
radiation, even when the source is at rest relative to the observer. Recent
ly we measured angular spectrum redistribution, or frequency shifts from a
real image of a point source, and further verified the coherent interferenc
e effect of a finite-band source. (C) 2001 Optical Society of America.