Analysis of low-coherence interference fringes by the Kalman filtering method.
Interferometers with low-coherence illumination allow noncontact measurement of rough-surface relief with a wide range of measurement definition by locating the visibility maxima of interference fringes. The problem is light scattering by the surface to be measured, which can cause distortion of low-coherence interferometric signals. We propose to use a stochastic fringe model and a Kalman filtering method for processing noisy low-coherence fringes dynamically. Prediction of the fringe's signal value at each discretization step is based on all the information available before this step; the prediction error is used for dynamic correction of the estimates of the fringe envelope and phase. The advantages of the Kalman filtering method consist in its immunity to noise, optimal fringe evaluation, and data-processing speed.
Gurov
Igor
I
Saint Petersburg Institute of Fine Mechanics and Optics (Technical University), 14 Sablinskaya Street, Saint Petersburg 197101, Russia. ig@spb.runnet.ru
Ermolaeva
Elena
E
Zakharov
Alexey
A