一种舰船轴频电场实时检测方法

A Real-time Detection Method of Ship’s Shaft-rate Electric Field

摘要:

为了能够在低信噪比的条件下提高目标的检测概率,降低目标的漏警率和虚警率,提出了一种基于信号特征的舰船轴频电场实时检测方法。 根据舰船的螺旋桨转速与轴频的对应关系确定了特征频段, 将特征频段内经过线谱、连续谱分离及线谱识别后的功率谱估计的最大值作为特征量。 根据环境变化,设置具有自适应功能的动态阈值,对信号进行实时检测,确定疑似目标点。 然后通过模量判断,线谱倍频判断和线谱稳定性判断,最终确认目标是否存在。 对仿真信号和实测信号进行了特征提取和检测,在不同海况和较低信噪比下实现了目标检测。

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.