Three-dimensional particle tracking velocimetry (3D PTV) is a flow mea
surement technique for the determination of velocity vectors and traje
ctories within a three-dimensional observation volume. This makes this
technique suitable not only for Eulerian but also for Lagrangian inve
stigation of flow phenomena, especially in the field of turbulence and
turbulent diffusion. The principle and the application on open channe
l flow of 3D PTV are briefly described in the first part of this paper
. By decomposition of the velocity vectors velocity profiles and turbu
lence intensities are derived and presented in the second part. Turbul
ent energy dissipation, Kolmogorov length and time scales and Taylor m
icro scales are computed from the measured data sets. In the Lagrangia
n analysis pdf's of the Lagrangian acceleration, correlation coefficie
nts and Taylor micro scales are determined. The individual determinati
on of the particle positions and displacements allows finally the appl
ication on the one and two particle approaches for turbulent diffusion
from Taylor (1921), Richardson (1926) and Batchelor (1949, 1952).