Scaling and intermittency of Lagrangian velocity in fully developed turbulence

We have developed a new experimental technique to measure the Lagrangian velocity of tracer particles in a turbulent flow. We observe that the Lagrangian velocity spectrum has an inertial scaling range $E^{L}(\omega) \sim \omega^{-2}$, in agreement with a Kolmogorov picture. Single particle velocity increments display an intermittency that is as pronounced as that in the Eulerian framework. We note that in the Lagrangian case, this intermittency can be described as a stochastic additive process.