An algorithms of underwater moving-target dynamic line spectrum enhancement

Traditional short-term autocorrelation-based adaptive line spectrum enhancer (SABALSE) becomes low in suppressing Gaussian noise when input signal-to-noise ratio becomes low. For greatly overcoming this disadvantage, based on the advantage of higher order cumulants in handling Gaussian noise and their different updating algorithms, the new algorithms of different slices of fourth-order cumulant-based adaptive dynamic line spectrum enhancer are proposed. These algorithms include the algorithm of non-diagonal slice of cumulant-based adaptive dynamic line spectrum enhancer (NDSCBADLSE) and that of diagonal slice of cumulant-based adaptive dynamic line spectrum enhancer (DSCBADLSE). Their conceptual schemes are analyzed in detail. The torpedo-radiated line spectra are enhanced dynamically under condition of different azimuth angles between the torpedo and the hydrophone. The results have shown that the NDSCBADLSE algorithm outperforms the DSCBADLSE algorithm in handling Gaussian noise and enhancing dynamic line spectrum, and that the performance of the NDSCBADLSE and DSCBADLSE algorithm is far better than the SABALSE algorithm. Accordingly, the proposed algorithms may be applied in improving the ability of underwater detection and weapon system to detect underwater target.