Figure 5
From: Passive acoustic measurement of flow velocity in the Straits of Florida
Comparison of the fine structure of noise cross-correlations at positive and negative time delays. (a) The noise cross-correlation function C12 is shown for positive (solid line) and negative (dashed line) time delays after removal of the relative drift of system clocks. The entire available data set is used for noise averaging. (b) Same as (a) but for C23. (c) Correlation between the positive- and negative-time-delay parts of the cross-correlation functions C12 (solid line) and C23 (dashed line). The position of the peak of the correlation of correlations determines the nonreciprocity of travel times induced by currents at sound propagation between the respective pair of instruments.