Mp. Wernet et A. Pline, PARTICLE DISPLACEMENT TRACKING TECHNIQUE AND CRAMER-RAO LOWER-BOUND ERROR IN CENTROID ESTIMATES FROM CCD IMAGERY, Experiments in fluids, 15(4-5), 1993, pp. 295-307
An efficient video based, multi-frame particle displacement tracking t
echnique is presented. The technique is demonstrated on a thermocapill
ary flow. The Cramer-Rao lower bound centroid measurement uncertainty
is derived for Gaussian particle images with Poisson noise recorded on
a CCD array. The optimal particle image diameter is determined to be
approximately 1 1/2 pixels. The centroid error increases for particle
image diameters larger or smaller than the optimal value. The particle
centroid results are carried over to the case of a cross-correlation
peak centroid estimate. Particle tracking techniques are shown to have
higher accuracy than auto or cross-correlation techniques when the in
dividual velocity measurements are averaged over a comparable correlat
ion subregion.