Modeling and correction of peak-locking in digital PIV

The systematic tendency of PIV evaluations to bias towards integral pixel values is known as peak-locking. These errors, although small, significantly affect the statistics extracted from such measurements. In this paper, the process by which such errors accrue is modeled, and a scheme for the removal of the same is suggested. Specifically, the modeling process considers FFT PIV with discrete window offset. The results are applied to actual situations and the results are found to be encouraging. The process is computationally inexpensive, and can be applied as a post processing technique to existing data to correct peak-locking.