Fluctuations and Directionality in Ambient Sea Noise Available to Purchase

Measurements of relative intensity of ambient sea noise in an octave band at 1 kc/sec for 32 directions of arrival in three dimensions are reported. The results, although obtained with improvement equipment, do not differ from those reported earlier by Becken. Some basis exists for questioning array performance. Rectified beam outputs, averaged for 1 sec, are found to have much more variability, particularly on a time scale of one or more minutes, than would be implied by Gaussian statistics.