
High/Low-Precision Digital Speckle Pattern
Interferometry for Vibration Measurement
Jia Shuhai,Yue Kaiduan,Zhao Hong,TanYushan
(Xi'an Jiaotong University, Xi'an 710049, China)
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Abstract: High/low-precision digital speckle pattern interferometry
(DSPI) is proposed for measuring vibration. The system combines the common DSPI optical
path for measuring out-plane vibration and the de-sensitized optical path. High and low
precision measurements are made such that the wrapped phase map obtained with high
precision can be unwrapped according to that for the low precision. Effectiveness of the
unwrapping procedure at the discontinuous area made it possible to analyze the vibration
characteristics of complex and discontinuous structure for engineering application.
Keywords: digital speckle pattern interferometry (DSPI);vibration
measurement;phase-shifting;phase unwrapping