Optical device for measuring the speed of extended scattering objects

摘要

This paper discusses an optical speedometer that forms an optical measurement volume of definite form in the area in which the speed of the object is to be measured and computes the autocorrelation function of the temporal signal of the photodetector. The computation of this function opens up the possibility of measuring the speed of rough extended objects for which a random function of the reflectance of such objects transforms into a set of correlation peaks. The interval between the peaks is determined by the distance between the illumination spots in the measurement volume and the velocity of the object. Stability of the parameters of the measurement volume makes it possible to measure the speed of objects in wide limits all the way to the lowest values.