Aerial photographs of the sun's glitter on the sea surface, taken under carefully chosen conditions in the Hawaiian area, were coordinated with measurements of winds (1-27 knots) from a vessel….
Cox, Charles, and Walter Munk. 1954. "Statistics of the sea surface derived from sun glitter." Journal of Marine Research 13, (2). https://elischolar.library.yale.edu/journal_of_marine_research/814