Arctic ambient noise statistical measurement results and their implications to sonar performance improvements

Abstract

Recent analyses of FRAM II arctic data have shown that under ice ambient noise can be at times highly impulsive and non-Gaussian. The analyses included time domain statistical measurements which were consistent with previously reported results of experiments made within the Canadian Arctic Archipelago. New findings of frequency domain estimates of complex skew and kurtosis and cumulative distribution functions, measured in 2, 6, and 10 Hz resolution cells at the output of a discrete Fourier transform, also indicate the existence of strong non-Gaussian noise. It is known that the ability to detect and estimate signals contaminated with non-Gaussian noise using conventional processing is degraded compared with optimum techniques which utilize knowledge of the noise statistics. The FRAM I1 data results suggest that sonar performance can be improved in the arctic environment by optimum signal processing methods.