**6. Conclusions**

This study has shown that an earlier-exercised mathematical framework lends itself well to extracting interpretive autospectral models of wind farm wake turbulence from a database. While these models are database specific, the framework can be applied to any database and the model construction is straightforward. As to the two-point statistics of wake-turbulence, this study first presents a unified account of cross-spectrum and coherence for HIT; this account is of considerable utility in that, in the literature, the expressions of cross-spectrum and coherence show differences from one study to the other. Given these expressions of coherences, this study then builds a framework for extracting wake turbulence coherence models from a database. The frameworks for autospectra and coherences do not follow classical perturbation theory approach of a solution for a linearized problem along with successively added corrections. Both frameworks represent a practical combination of a series expansion, exploitation of a database, and theoretical constraints in closed form.

This study also leads to following specific findings:


**Author Contributions:** All authors contributed equally and effectively to the paper.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
