An analysis of the frequency spectrum of laser light scattered from moving rough objects*

The frequency spectrum of laser light scattered from moving rough objects is examined by temporally Fourier transforming the mutual coherence function describing the scattering. The motion of the object is introduced through the temporal dependence of the spatial variables of the mutual coherence function. A simple Doppler shift model is shown to provide a first approximaion to the result derived via coherence theory, for fully illuminated objects. An expression for the frequency broadening caused by the limited observation interval of a given rough-surface area is derived, and the correspondence with previous results is noted.