稲富 裕光

In the phase analysis, accuracy can degrade when the intensity of bright and dark lines in interference fringes varies significantly spatially, or when the phase change Δφ is temporally discontinuous. In this study, we improved the interference fringe analysis method by focusing on a local region in phase analysis and classifying phase inter-frame differences δφ’ in phase unwrapping. The objective of this study is to clarify how to set the threshold for classifying δφ’ and the accuracy of the phase φ and phase change Δφ obtained by the proposed method. Both experimentally obtained in a microgravity and artificially generated interference fringes were analyzed using the proposed method. As a result, the obtained spatial distribution of Δφ had a few outliers. In addition, it was revealed that a reliable threshold for classifying δφ’ can be automatically determined by using the total amount of tolerable noise and estimated δφ’. The phase error and the phase change error were as small as 0.025π and 0.034π rad, respectively, which is less than one-fifth of the conventional method.