Estimation of Unknown Phase Shift Between Synthesized Speckle Interferograms Using Pearson Correlation Coefficient

A sample Pearson correlation coefficient (SPCC) is proposed to calculate an unknown phase shift (UPS) between speckle fringe patterns (speckle interferograms (SIs)) of the same test object. The SI sequences of an initial flat optically rough surface and the SI sequences of a deformed surface were synthesized to estimate the systematic errors of the UPS extraction. The low level of these errors in the range from 0 to 180 degrees proves the effectiveness of using the SPCC to extract the UPS.