Patent ID: 7280187

Claim:
A method of determining the phase difference for speckle interferograms, the method comprising the steps of: a) record the intensities along arm 1 I 1 b) record the intensities along arm 2 I 2 c) record the interference intensities I F1 at time t1, d) record the interference intensities I F2 at time t2, where t2>t1 e) compute θ1′=cos −1 [(I F1 −I 1 −I 2 )/2√{square root over (I 1 I 2 )}] f) compute θ2′=cos −1 [(I F2 −I 1 −I 2 )/2√{square root over (I 1 I 2 )}] g) compute (sin [(θ2′−θ1′)/k]), h) compute Max of the results in step g i) compute Min of the results in step g j) compute γ=(Max−Min)/2 k) compute (1/γ)[Φ(θ2′−θ1′)] where Φ is a bounded trig function; l) determine the phase by computing Φ −1 of the results in step k.