Agradecimentos: This study was supported in part by the Sao Paulo Research Foundation (FAPESP) under Grant 2017/25666-2, in part by the ‘Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under Grants 403418/2021-6 and 309989/2021-3, and in part by the Coordenacao de...

Agradecimentos: This study was supported in part by the Sao Paulo Research Foundation (FAPESP) under Grant 2017/25666-2, in part by the ‘Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under Grants 403418/2021-6 and 309989/2021-3, and in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) under Finance Code 001

Abstract: Laser speckle-based systems provide sensitive measurements of displacement and stain. However, the typical saturation of correlation functions restricts the application of such techniques regarding their dynamic range. Therefore, this paper proposes using the extended zero-mean normalized...

Abstract: Laser speckle-based systems provide sensitive measurements of displacement and stain. However, the typical saturation of correlation functions restricts the application of such techniques regarding their dynamic range. Therefore, this paper proposes using the extended zero-mean normalized cross-correlation (EZNCC) algorithm to automatically update the reference speckle image according to a programmable threshold, allowing for exceeding the decorrelation limit. Experiments investigated the effect of rigid body displacements and thermal strain at the light scattering surface (a ceramic container). The EZNCC yielded similar to 30 mu m resolution over a continuous 1500 mu m range for displacement measurements, and similar to 0.2 degrees C resolution between 21.5 degrees C and 61.5 degrees C for the temperature analysis. As this method requires minor updates to the traditional correlation algorithms, the ENZCC does not require modifications to the optical setups, improving the dynamic range and ensuring the high sensitivity of speckle correlation systems in a feasible, straightforward approach

FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP

2017/25666-2

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ

403418/2021-6; 309989/2021-3

COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES

001

Fechado