The proper orthogonal decomposition (POD) method to identify coherent structures in turbulent boundary layers is not very new idea. However, our method is different. By using linear combination of POD modes of enstrophy (square of vorticity) we are able to characterize the spatial form and scales of the structures. Please, see our recent work in Int. J. of Heat and Fluid Flow [doi link]. This research complements the work with Iztok Tiselj in which we use direct numerical simulation (DNS) data and perform the same procedure [Theor. Comp. Fluid Dyn.]. The resemblence is very nice, isn't it?