Optimal observations of stationary turbulence with Lagrangian drifters

The authors develop techniques for estimating homogenous turbulence based on Lagrangian position measurements. They thereby derive estimates for the diffusivity, Lagrangian time scale, turbulent variability, and mean flow. They then show that there exists an observation time interval that produces optimal estimates in the sense that they are consistent, asymptotically unbiased and have minimum variance. These estimates do not depend on arbitrary truncation or the long time behavior of the autocorrelation function, thus producing reliable estimators with objective error estimates. Finally, they test their estimators on drifter data from the Brazil-Malvinas extension and compare the results with previous work done in this region