A comparison between spectral and bispectral analysis for ship detection from acoustical time series

An acoustic underwater communication problem is considered at low frequency ranges (up to 1 kHz), where propagation performances are improved. This range is dominated by ship noise components and is expected to be non-Gaussian. Classical detector performances may decay in the presence of non-Gaussianity. Spectrum-based and bispectrum-based methods have been used and compared to statistically characterize shipping noise and then to design non-conventional detectors; the main process properties are stationarity, frequency composition and coupling, Gaussianity. Analysis results are reported and refer to real acoustic data recording background traffic and a known-target-ship passage.<>