Acoustic spatial correlation and random oceanic fluctuations

The spatial correlation of a low‐frequency acoustic wave which has propagated through an oceanic medium with random fluctuations in the sound speed is examined from the point of view of beam patterns and array performance. The nature of the temperature component of the sound‐speed variability is described together with a general Bethe‐Salpeter equation for the acoustic field correlation function. Comparisons are made between a theoretical solution for the transverse acoustic correlation and archival measurements. The qualitative nature of the variation of the correlation with range, receiver separation, and frequency are shown.