The Elimination of Correlation Errors in PIV Processing

A non-post-interrogation method of reducing sub-pixel bias errors and eliminating spurious vectors from particle image velocimetry (PIV) results is presented. Unlike methods that rely on the accuracy or similarity of neighboring vectors, errors are eliminated before correlation information is discarded using available spatial and/or temporal data. Anomalies are removed from the data set through direct element-by-element comparison of the correlation tables calculated from adjacent regions. The result is in an error correction method that is highly robust to out-of-boundary particle motion, particle overlap, inter-particle correlations, and electronic and optical imaging noise. Consequently, the sample volume size required to resolve tracer particle displacement can be reduced improving the resolution as well as the accuracy of PIV. 1