Optical preprocessing in a laser-speckle correlation measurement technique for the determination of engineering strain within a specimen

1998 ◽  
Author(s):  
Christian M. Kargel ◽  
Bernhard G. Zagar
Keyword(s):  
Measurement Technique ◽  
Laser Speckle ◽  
Correlation Measurement ◽  
Engineering Strain ◽  
Speckle Correlation

Determination of the plastic zone by laser-speckle correlation

1991 ◽  
Vol 31 (4) ◽  
pp. 348-352 ◽  
Author(s):  
Y. Z. Dai ◽  
C. J. Tay ◽  
F. P. Chiang
Keyword(s):  
Plastic Zone ◽  
Laser Speckle ◽  
Speckle Correlation

scholarly journals A New Pattern Quality Assessment Criterion and Defocusing Degree Determination of Laser Speckle Correlation Method

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4728
Author(s):  
Wenxin Hu ◽  
Zhipeng Sheng ◽  
Keyu Yan ◽  
Hong Miao ◽  
Yu Fu
Keyword(s):  
Quality Assessment ◽  
Speckle Pattern ◽  
Correlation Method ◽  
Quality Criterion ◽  
Laser Speckle ◽  
Widespread Application ◽  
Speckle Correlation ◽  
Speckle Patterns ◽  
Speckle Size

The laser speckle correlation method has found widespread application for obtaining information from vibrating objects. However, the resolution and accuracy of the laser speckle correlation method as they relate to the defocusing degree have not been analyzed sufficiently. Furthermore, the possible methods for speckle pattern quality assessment and enhancement have not been studied. In this study, the resolution and accuracy of the laser speckle correlation method are analyzed, and it is found that they are affected by the defocusing degree and speckle pattern quality, respectively. A new speckle pattern quality criterion combining the mean intensity gradient and frequency spectrum was proposed, called CMZ. The quality of the speckle pattern is higher when the CMZ is closer to zero. The proposed criterion was verified by simulated speckle patterns and real speckle patterns with different speckle sizes, densities, and gray contrasts. In the experimental setup stage, a suitable defocusing degree can be selected based on the resolution requirement and optimal speckle size, and other experimental parameters can be determined according to the CMZ criterion. Rotation and vibration experiments verified the effectiveness of the laser speckle correlation method and confirmed the reliability of the experiment preparation based on proposed CMZ criterion.

scholarly journals Determination of the Precise Coordinates of the GPS Reference Station in of a GBAS System in the Air Transport

2020 ◽  
Vol 22 (3) ◽  
pp. 11-18
Author(s):  
Kamil Krasuski ◽  
Stepan Savchuk
Keyword(s):  
Mathematical Model ◽  
Measurement Technique ◽  
Air Transport ◽  
Reference Station ◽  
The Real ◽  
Station Coordinates ◽  
Geocentric Coordinates

This paper presents results of research concerning determination of the GPS reference station coordinates located on the grounds of an EPDE airport in Deblin. The study uses a mathematical model of the PPP measurement technique in order to determine the coordinates of the reference station using the real GPS code-phase observations. The computations of the coordinates of the GPS reference station were carried out in numerical applications CSRS-PPP, APPS and GAPS. In this research was found that the accuracy of finding solutions to the XYZ geocentric coordinates of the reference station REF1 between solutions CSRS-PPP, APPS and GAPS ranges from 0.01m to 0.13m. In addition, the accuracy of determining the XYZ geocentric coordinates from the PPP method related to the GPS differential solution ranged from 0.01m to 0.11m.

Laser hole drilling process studied using laser speckle correlation

2006 ◽  
Author(s):  
Mikael Sjödahl ◽  
Per Gren ◽  
Istvan Sárady ◽  
Natalia Miroshnicova
Keyword(s):  
Laser Speckle ◽  
Hole Drilling ◽  
Drilling Process ◽  
Speckle Correlation

Opto-mechanical magnetometer based on laser speckle correlation

Measurement ◽  
2021 ◽  
pp. 110490
Author(s):  
Vismay Trivedi ◽  
Swapnil Mahajan ◽  
Mugdha Joglekar ◽  
Nirav Joshi ◽  
Vani Chhaniwal ◽  
...  
Keyword(s):  
Laser Speckle ◽  
Speckle Correlation

Event-based laser speckle correlation for micro motion estimation: erratum

2021 ◽  
Vol 46 (20) ◽  
pp. 5083
Author(s):  
Zhou Ge ◽  
Yizhao Gao ◽  
Hayden K.-H. So ◽  
Edmund Y. Lam
Keyword(s):  
Motion Estimation ◽  
Laser Speckle ◽  
Speckle Correlation ◽  
Micro Motion ◽  
Event Based
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