Abstract:In order to improve the detection probability of target and reduce the missed alarm rate and false alarm rate under the condition of low SNR, a real-time detection method of ship’s shaft-rate electric field based on signal characteristics is proposed. According to the corresponding relation between the propeller rate and the shaft rate of ship, the characteristic frequency band is de- termined, and the maximum value of the power spectrum estimation after the line spectrum, the continuous spectrum separation and the line spectrum identification in the characteristic frequency band is taken as the feature quantity. According to environmental chan- ges, dynamic thresholds with adaptive functions are set to detect signals in real time to determine suspected target points. Then, through modulus judgment, line spectrum multiplication judgment and line spectrum stability judgment, whether the target exists is finally confirmed. The feature extraction and detection of the simulated signal and the measured signal are carried out, and the target detection is realized at different sea states and under low SNR.
