Characteristics of the Wind - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 521

Figure 8-31. Sample autocorrelation functions for wind speeds across the swept area of
the Mod-OA HAWT, calculated using Equations 8-31 and the Dryden correlation coef-
ficients. Rotationally-sampled turbulence spectra are obtained from these functions.
Figure 8-32. Sample Lagrangian turbulence spectra calculated from the autocorrelation
function in Figure 8-31, at a radius of 19.05 m. [Powell et al. 1985]