Time-frequency Identification of Weak Warship Signals in Complex Sea State Background
YU Li-yang · Acta Armamentarii · 2009
The signal time-frequency analysis was applied to identifying the weak physical field signals of warship in complex sea state background.The cross-interference problem of Wigner-Ville distribution in weak signal identification was analyzed.To restrain the cross interference and improve time-frequency resolution,a high-order Butterworth pre-filter was introduced into a hydraulic pressure field collecting system and an algorithm of smooth pseudo Wigner-Ville distribution(SPWD) with Blackman window was brought forward.Based on a sea experiment of warship hydraulic pressure measure,the algorithm was validated and contrasted.The results show that the algorithm can improve ability of identifying the weak warship signals obviously in complex sea state.