Dynamic electronic speckle pattern interferometry (DESPI) phase analyses with temporal Hilbert transform

Abstract

In this study, we propose the Hilbert transform (HT) method for phase analysis of a Dynamic ESPI signal. The data processing is performed in the temporal domain, using the temporal history of the interference signal at every single pixel. The final results give a temporal development of the two-dimensional deformation field. To reduce the influence of the fluctuations of bias intensity on the calculated phase, it was removed prior to performing the HT. This method was demonstrated for defects distinction and the determination of the sign change in the deformation field in two different experiments. The range of measurement lies between submicrons and tens of microns and the spatial resolution is better when compared to the fringe analysis method and the spatial carrier method.

A Study of Three-Dimensional Measurement By Transmission Deflectometry and Hilbert Transform

“…TPU 경우에는 위상을 추출하기 위해 여러 장의 영상을 필요로 하나, Fourier 변환을 이용하는 경 우에는 단 1장의 영상만을 필요로 해서 빠른 측정이 가능하 다는 장점이 있다. 최근 위상을 추출하는 방법으로 Hilbert 변환법이 제시 되었다 [17][18][19][20] . [10,11] .…”

New Trends in Dental Biomechanics with Photonics Technologies

“…This technique is based on interference of the scattered light from the specimen with a reference speckle pattern, and the resultant pattern shows also a randomly-distributed intensity [54]. The changes in the object state, like deformation and displacement, are proportional to the phase changes within each speckle.…”

Sistema De Shearografía para el Análisis Dinámico de Materiales bajo Estrés Térmico

“…Cada uno de los cuadros de esta secuencia es restado con el cuadro inicial o referencia para obtener una nueva secuencia con patrones franjeados como los que se muestran en la parte derecha de la ¡Error! No se encuentra el origen de la referencia.. En este punto, la intensidad de cada uno de los patrones franjeados en cada cuadro de la secuencia se pueden describir matemáticamente de la siguiente forma (Madjarova et al, 2003):…”

“…Esta función, es de la forma ( ( )) ( ( )) a la cual se le asocia su función conjugada a través de las propiedades de la transformada de Hilbert. De esta manera, se tiene que { ( ( ))} ( ( )) y se puede obtener la fase por medio de la siguiente ecuación (Madjarova et al, 2003;Toyooka et al, 2006):…”