Comparison of Gaussian particle center estimators and the achievable measurement density for particle tracking velocimetry

TitleComparison of Gaussian particle center estimators and the achievable measurement density for particle tracking velocimetry
Publication TypeJournal Article
Year of Publication2000
AuthorsMarxen, M, Sullivan, PE, Loewen, MR, Jähne, B
JournalExp. Fluids
Volume29
Pagination145-153
Abstract

A series of numerical simulations were conducted to investigate the performance of two particle center estimation algorithms for Particle Tracking Velocimetry: a simple three-point Gaussian estimator and a least-square Gaussian. The smallest position error for images with reasonable noise levels was found to be approximately 0.03 pixels for both estimators using particles with diameters of 4 pixels. As both estimators performed equally well, use of the simple three-point Gaussian algorithm is recommended because it executes 100 times faster than the least-square algorithm. The maximum achievable measurement density and accuracy for the three-point Gaussian estimator were determined with a numerical simulation of an Oseen vortex. Uncertainty measures have been introduced to filter out unreliable displacement measurements. It was found that 4 to 5 velocity vectors could be obtained within a 32×32 pixel area with an average displacement error of 0.1 pixels. This doubles the spatial resolution of conventional cross-correlation based Particle Image Velocimetry at comparable accuracy.

DOI10.1007/s003489900085
Citation Keymarxen2000