A state space model for the determination of dual phase distributions in a holographic moiré in the presence of nonsinusoidal waveforms, random noise, and miscalibration of the piezoelectric (PZT) devices is proposed. The extraction of these phase terms requires incorporating two PZTs into the moiré setup. A Toeplitz approximation method (TAM) is applied for phase determination, and modification to the Toeplitz covariance matrix formed from the phase-shifted moiré fringes by application of a denoising step in the state-feedback matrix is proposed. This step ensures that the phase terms can even be estimated at a signal-to-noise ratio much lower than that of the original TAM or by our previously suggested polynomial based method.
© 2005 Optical Society of America
(090.2880) Holography : Holographic interferometry
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.4120) Instrumentation, measurement, and metrology : Moire' techniques
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
Abhijit Patil, Rajesh Langoju, and Pramod Rastogi, "Model-based processing of a holographic moiré," Opt. Lett. 30, 2870-2872 (2005)