INVESTIGATION OF THE ACCURACY OF THE CORRELATION METHOD AND ITS IMPROVEMENT BY USING SIMULATED PARTICLE IMAGES

Accuracy of the correlation method is examined by simulating tracer particle images which follow uniform or shear flow velocity distributions. Velocity differences between given and calculated values are examined for various sizes of reference frames. Also, two methods for obtaining intermediate particle positions between the centers of pixels are presented. One of the methods uses linearly interpolated intensity of the image between pixels (Method A) and the other utilizes the distribution of cross-correlation coefficients (Method B). Both methods are found to be effective in improving the accuracy of the correlation method.