Stoffregen, B. and Felske, A., "Scanning Laser Doppler Vibration Analysis System," SAE Technical Paper 850327, 1985, doi:10.4271/850327.
The newly developed optical instrument for vibration analysis is based on the laser Doppler effect that can be used to measure the vibration velocity of object surface points. The new system “SOVAS” (Scanning Optical Vibration Analysis System) analyzes the vibration amplitude of whole surface areas by means of computer controlled laser scanning and fast Fourier transform of the velocity signals derived from Doppler frequency modulation. As results frequency spectra of single points as well as vibration patterns of up to seven simultaneously measured frequency ranges can be displayed. The presented paper gives a detailed description of “SOVAS” and some typical applications in vibration analysis of car body and engine parts.