Sub-Pixel Processing in Successive Abandonment Algorithm of PIV

In Particle Image Velocimetry (PIV), the successive abandonment algorithm is known as one of the efficient technique, and it has been widely applied to velocity field analysis of fluid flows. In order to improve this technique as a high accurate technique for the wide dynamic range, the establishment of a sub-pixel processing is required. In this paper, a new calculation method in the successive abandonment algorithm is proposed as a technique of the sub-pixel processing in which the complemental error-function is used as the fitting function for the distribution of normalized accumulated-intensity-difference. The technique was applied to reconstruct velocity vector map of a synthetic PIV image. The results obtained show that the technique described here meets the requirement of fine sub-pixel processing of PIV image with only slight increase of the total processing time.