摘要
通过对海上记录时间大于4h的几十条水声目标噪声进行归一化短时谱图即船谱图方法分析，归纳出一些典型的瞬态信号的时频分布形态。有竖条分布、横条分布、“麻花状”的共振峰滑动型和能量集中的正方型分布等，为进一步研究和识别瞬态信号打下基础。文章还调查了谱相关技术（二阶累积量谱）在干扰噪声中检测水声瞬态信号的性能。计算机模拟和对18个实际瞬态信号的分析说明用谱相关技术检测瞬态信号的有效性，近80％的实际信号比常规功率谱检测有3～6dB的增益。文章最后研究用谱相关提取瞬态信号模态的技术，给出了3个无源目标瞬态信号模态较清晰的图像，为识别瞬态信号提供特征。
The features of the transient signals produced by vessel are investigated using normalized short time spectrum. The survey covers 4 hour data recorded on the sea including 43-vessel noise. Some typical kinds of time-frequency distribution of passive transient signals are categorized. The spectral correlation (second order cumulant spectrum) is adopted to detect passive underwater transient signals. The analysis of 18 underwater transient signals demonstrates the significant processing gains. The last section of the paper analyzes the modes of these passive transient signals using spectral correlation. The modes──one mono, another triple.and third penta ── are distinctively identifiable,presenting themselves as useful features in classification of transient signals.
出处
《声学学报》
EI
CSCD
北大核心
2000年第6期510-515,共6页
Acta Acustica
基金
国家自然科学基金!19774064
