We investigate the computation of the Lagrangian second-order structure-function for describing the multiscale dy- namics of turbulence based on measured particle trajectory data. Using time-resolved three-dimensional particle tracking velocimetry (4D-PTV), we statistically quantified turbulent properties of the anisotropic and inhomogeneous flow fi eld be hind a cy linder at a Reynolds number of 3900. La grangian statistical analysis has been performed on nearly 12000 trajectories for 4000 time steps.