摘要
现代多波束测深声呐在检测海底地形的同时往往也有检测水中目标的需求,常见的多回波检测方法基于回波幅度设置检测门限,其对波束内幅度相当的回波检测是有效的,但是当多目标反向散射能力强弱导致的回波幅度悬殊时,基于幅度门限方法难以奏效。针对此问题,提出了一种基于瞬时频率方差及谱特征联合加权的方法,在利用回波幅度的基础上进一步利用了相位信息。首先利用回波信号相位特性求得回波信号的瞬时频率方差,其次对信号的谱特征进行分析求取回波信号的等效带宽,最后利用所得的等效带宽数值与瞬时频率方差数值极低甚至近似为0的特性,联合对回波幅度进行加权,凸显被强目标信号淹没的弱目标回波信号,便于强弱目标的同时检测,提高对弱目标的检测能力。计算机仿真结果显示经过联合加权后,强弱目标的相对幅度提升了近30%,并且检测能力得以有效提高。通过外场试验数据处理结果可以发现,经过瞬时频率方差及谱特征加权处理的目标回波检测能力得到明显的改善。
The traditional threshold setting method of multi beam sonar multiple detection technology is effective for the detection of multiple echoes with the same beam amplitude.When the echo amplitude is different,the conventional threshold setting method is difficult to adapt and adjust.To address this issue,a joint weighting method based on instantaneous frequency variance and spectral characteristics is proposed to weight the echo amplitude.The instantaneous frequency variance of the echo signal is obtained by using the characteristic that the phase of the echo signal is regular.The spectral characteristics of the signal are analyzed to obtain the equivalent bandwidth of the echo signal.Using the characteristics that the obtained equivalent bandwidth value and the instantaneous frequency variance value are very low or even close to 0,the echo signal of weak target submerged by strong target signal is highlighted,which is convenient for the simultaneous detection of strong and weak targets and improves the detection ability of targets.Computer simulation results show that after joint weighting,the relative amplitude of strong and weak targets is increased by nearly 30%,and the detection ability is improved.Through the field test data processing results,it can be found that the target echo detection ability after instantaneous frequency variance and spectral feature weighting processing has been significantly improved.
作者
高家伟
周天
杜伟东
徐超
Gao Jiawei;Zhou Tian;Du Weidong;Xu Chao(College of Underwater Acoustic Engineering,Harbin Engineering University,Harbin 150001,China;Acoustic Science and Technology Laboratory,Harbin Engineering University,Harbin 150001,China;Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering University),Ministry of Industry and Information Technology,Harbin 150001,China)
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2022年第8期193-203,共11页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金(42176188,42176192,41976176,52001097)项目资助
关键词
瞬时频率
瞬时频率方差
等效带宽
联合加权
instantaneous frequency
instantaneous frequency variance
equivalent bandwidth
joint weighting
