Mapping LDV Noise As A Function Of Standoff Distance,Beam Focus, And Surface Roughness

摘要

This paper reports on a series of experiments intended to quantify the effect of surface roughness, laser focus, and measurement standoff distance on the noise in laser Doppler vibrometry measurements. A series of measurements of the noise signal were made with a single point laser vibrometer at normal incidence on solid aluminum surfaces sanded with 80- and 1000-grit abrasive. The parameters varied for this study were the standoff range and the focus of the instrument, which determines the spot size.