@article {marxen2000,
	title = {Comparison of Gaussian particle center estimators and the achievable measurement density for particle tracking velocimetry},
	journal = {Exp. Fluids},
	volume = {29},
	year = {2000},
	pages = {145-153},
	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{\texttimes}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.},
	doi = {10.1007/s003489900085},
	author = {Michael Marxen and Sullivan, P. E. and Loewen, M. R. and Bernd J{\"a}hne}
}
@mastersthesis {marxen1998,
	title = {Particle Image Velocimetry in Str{\"o}mungen mit starken Geschwindigkeitsgradienten},
	year = {1998},
	school = {IWR, Fakult{\"a}t f{\"u}r Physik und Astronomie, Univ.\ Heidelberg},
	author = {Michael Marxen}
}
