Analysis of impulse train illuminated images for 2D velocity measurement

Numerous applications require a precise and angle sensitive measurement of the velocity of a textured surface. This article describes a contactless measurement scheme that analyzes the Fourier spectrum of images acquired under time varying illumination. Theoretical considerations and experimental studies suggest employment of impulse train illumination. It is shown that velocity measurement reduces to the estimation of the cycle distance and angle in a periodic line spectrum. Experimental results demonstrate that the method yields robust measurements and is capable of measuring large velocities.