TY - JOUR
T1 - Electronic speckle techniques in noisy environments
AU - Pouet, Bruno
AU - Krishnaswamy, Sridhar
N1 - Funding Information:
This work was carried out in the course of research sponsored by the FAA Center for Aviation Systems Reliability, operated by Ames Laboratory, USDOE, for the Federal Aviation Administration under
Funding Information:
This work was carried out in the course of research sponsored by the FAA Center for Aviation Systems Reliability, operated by Ames Laboratory, USDOE, for the Federal Aviation Administration under Contract No. W-7405-ENG-82 for work by Iowa State University and Northwestern University.
Publisher Copyright:
© 1993 SPIE. All rights reserved.
PY - 1993/12/10
Y1 - 1993/12/10
N2 - The main sources of noise that lead to speckle phase distortion and decorrelation are identified and methods to overcome these are suggested. An automated continuous reference updating technique is shown able to avoid speckle decorrelation induced by object drift or low frequency vibrations. A second improvement using the introduction of phase shift and the addition of surface information during every image acquisition, is demonstrated to insure fringe pattern stability even in the presence of relatively high frequency noise due to thermal currents or air flow. Furthermore, phase modulation is used to reduce the speckle effect by removing the speckle phase term. The application of these techniques to the task of nondestructive detection of structural defects in aluminum plates is demonstrated in a very noisy environment.
AB - The main sources of noise that lead to speckle phase distortion and decorrelation are identified and methods to overcome these are suggested. An automated continuous reference updating technique is shown able to avoid speckle decorrelation induced by object drift or low frequency vibrations. A second improvement using the introduction of phase shift and the addition of surface information during every image acquisition, is demonstrated to insure fringe pattern stability even in the presence of relatively high frequency noise due to thermal currents or air flow. Furthermore, phase modulation is used to reduce the speckle effect by removing the speckle phase term. The application of these techniques to the task of nondestructive detection of structural defects in aluminum plates is demonstrated in a very noisy environment.
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U2 - 10.1117/12.165485
DO - 10.1117/12.165485
M3 - Conference article
AN - SCOPUS:85076259559
SN - 0277-786X
VL - 2003
SP - 171
EP - 178
JO - Proceedings of SPIE - The International Society for Optical Engineering
JF - Proceedings of SPIE - The International Society for Optical Engineering
T2 - Interferometry VI: Techniques and Analysis 1993
Y2 - 11 July 1993 through 16 July 1993
ER -