检索结果-南通市图书馆

The Technology of Line-spectrum Enhancement Based on Image Processing

在线全文

学校读者我要写书评

暂无评论

The Technology of Line-spectrum Enhancement Based on Image P...

The 2011 International Symposium on Manufacturing Systems Engineering (ISMSE 2011)

作者： daizhu zhu Wenhua Huang Shanghai Marine Electric Equipment Institute

Time-frequency spectrogram analysis is a basic method in passive radar and sonar. It′s necessary to enhance the line-spectrum to improve the performance in low SNR（Signal to Noise Ratio） and strong interference presented that wider detecting range and long reacting time can be obtained. The traditional line-spectrum enhancing technology based on signal′s coherence can′t work well in very low SNR, and the performance will drop sharply when the line-spectrums are close in frequencies or the number of line-spectrums increases. A new method which combines image processing with signal processing is brought out to overcome these defects. It can work well when the SNR in frequency domain is close to 0d B,which is much lower than ALE and other traditional technology. The results derived from simulation and trial data analysis show that it′s stable and can be applied in the field with line-spectrums.

关键词： Time-frequency spectrogram line-spectrum enhancement line-spectrum extraction image processing detection and discrimination

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

基于线谱特征的三元组拖线阵左右舷分辨

声学学报 2009年第4期34卷 296-302页

作者：朱代柱杜选民上海交通大学船舶海洋与建筑工程学院上海200240 上海船舶电子设备研究所上海201108

传统的三元组拖线阵在分辨目标左右舷时利用左、右两侧的宽带能量之比,该技术在通常情况下能够较好地完成使命,但在实际应用中可能会遇到一些困难。本文针对两种影响其左右舷分辨结果的情况做了分析:一种是弱信噪比情况,另一种是另一舷... 详细信息

传统的三元组拖线阵在分辨目标左右舷时利用左、右两侧的宽带能量之比,该技术在通常情况下能够较好地完成使命,但在实际应用中可能会遇到一些困难。本文针对两种影响其左右舷分辨结果的情况做了分析:一种是弱信噪比情况,另一种是另一舷侧存在强干扰目标的情况。针对这两种情况,通过对左、右舷频谱特征的分析,提出了利用线谱特征提取结果分辨目标左、右舷的新技术,显著降低了左右舷分辨功能对输入信噪比的要求。仿真和对海上实验数据的处理结果验证了该方法的稳健性和有效性,可望应用于工程实践中。为了使该技术能够适用于更低的信噪比条件,本文还提出了一种简单实用的线谱增强技术。

关键词：左右舷分辨线谱特征拖线阵三元组增强技术信噪比干扰目标频谱特征

Block Iterative STMV Algorithm and Its Application in Multi-Targets Detection

在线全文

学校读者我要写书评

暂无评论

Journal of Applied Mathematics and Physics 2020年第7期8卷 1346-1361页

作者： daizhu zhu Haoquan Guo Yuanao Wei Kaiju Wang Shanghai Marine Electronic Equipment Research Institute Shanghai China

STMV beamforming algorithm needs inversion operation of matrix, and its engineering application is limited due to its huge computational cost. This paper proposed block iterative STMV algorithm based on one-phase regressive filter, matrix inversion lemma and inversion of block matrix. The computational cost is reduced approximately as 1/4 M times as original algorithm when array number is M. The simulation results show that this algorithm maintains high azimuth resolution and good performance of detecting multi-targets. Within 1 - 2 dB directional index and higher azimuth discrimination of block iterative STMV algorithm are achieved than STMV algorithm for sea trial data processing. And its good robustness lays the foundation of its engineering application.

关键词： Beamforming Steered Minimum Variance (STMV) Block Iterative Computational Cost Multi-Targets Detection

Block Iterative STMV Algorithm and Its Application in Multi-Targets Detection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Block Iterative STMV Algorithm and Its Application in Multi-...

The port/starboard discrimination based on line-spectrum character in towed line array with hydrophone triplets

作者： daizhu zhu Haoquan Guo Yuanao Wei Kaiju Wang Shanghai Marine Electronic Equipment Research Institute

STMV beamforming algorithm needs inversion operation of matrix, and its engineering application is limited due to its huge computational cost. This paper proposed block iterative STMV algorithm based on one-phase regressive filter, matrix inversion lemma and inversion of block matrix. The computational cost is reduced approximately as 1/4 M times as original algorithm when array number is M. The simulation results show that this algorithm maintains high azimuth resolution and good performance of detecting multi-targets. Within 1-2 d B directional index and higher azimuth discrimination of block iterative STMV algorithm are achieved than STMV algorithm for sea trial data processing. And its good robustness lays the foundation of its engineering application.

关键词： Beamforming Steered Minimum Variance(STMV) Block Iterative Computational Cost Multi-Targets Detection

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2011年第1期30卷 62-72页

作者： zhu daizhu DU Xuanmin Shanghai Marine Electronic Equipment Research Institute Shanghai 201108 School of Naval Architecture Ocean and Civil EngineeringShanghai Jiaotong University Shanghai 200240

The energy ratio of broadband signal is utilized for port/starboard discrimination in towed line array with hydrophone triplets in tradition. It works well in most conditions except for two cases： One is low signal to noise ratio（SNR）, and the other is that there is a stronger interference lied on the other side of the line array with approximate bearing angles. A method called line-spectrum character extracting is proposed to discriminate port/starboard for these two cases in this paper, and the SNR needed for port/starboard discrimination is reduced significantly. Simulation and the sea-trial data are analyzed to show that the method is stable and valid, and is expected to be applied in real towed line array sonar. A line-spectrum enhancing technology with lower calculation complexity and stable validity is proposed to ensure the application of this method in lower SNR condition.

关键词： line The port/starboard discrimination based on line-spectrum character in towed line array with hydrophone triplets

Theoretical analysis and experimental research on port/starboard discrimination in towed line array

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2001年第1期20卷 30-43页

作者： DU Xuanmin,zhu daizhu,ZHAO Rongrong,YAO Lan (Shanghai Marine Electronic Equipment Research Institute Shanghai 200025) Shanghai Marine Electronic Equipment Research Institute Shanghai 200025

The theoretical analysis and experimental research on Port/Starboard (P/S) discrimination in towed line array are proposed. Two methods resolving the P/S ambiguity with hydrophone triplets are introduced. By processing experimental data, the theoretical analysis is verified. The processing algorithm is extended to broadband signal. The research results show that the method based on optimum beamforming with triplets can be used to remove the port/starboard ambiguity. Also because of the simplicity of the method, it is expected to be implemented in practical towed line array sonar.

关键词： line Theoretical analysis and experimental research on port/starboard discrimination in towed line array

An experimental study on the sound scattering of the ship's wakes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 1999年第3期18卷 217-225页

作者： HUI Junying zhu daizhu CAI Ping LIU hong (Underwater Acoustic Engineering Departmetn, Harbin Engineering University Harbin 150001)

The experiments for the sound scattering of the ship wakes are introduced in this article. The wakes are detected in both horizon and vertical in lake trials and its traces are shown in display model A or B, Its size and sound scattering strength are measured also. The scattering signals are analysed with the instananeous frequency sequence statistics methods

关键词： An experimental study on the sound scattering of the ship’s wakes

A detecting method for line-spectrum target based on variance-of-frequency weight

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Acoustics 2011年第2期30卷 126-132页

作者： zhu daizhu WANG Zijuan CHEN Yang Shanghai Marine Electronic Equipment Research Institute Shanghai 201108 School of Naval Architecture Ocean and Civil Engineering Shanghai Jiaotong University Shanghai 200240 National Laboratory of Underwater Acoustic Technology Harbin Engineering University Harbin 150001

There are highly intensive and stable line-spectrums in the radiated noise of passive target,and different targets have line-spectrums with different *** paper puts forward Conventional BeamForming（CBF） variance-of-frequency detector,which weights bearing spectrum using the variance of frequency of line spectrum with maximum amplitude in each azimuth. It is able to suppress multi-target interferences effectively,and detect faint signal in the background of strong ***＇s more,CBF variance-of-frequency detector needs only three-dimension display,while other line-spectrum detectors require for four-dimension *** simulation and trial data analysis show that the CBF variance-of-frequency detector is able to detect faint line-spectrum target in the background of the continuous spectrum strong interferences.

关键词： line A detecting method for line-spectrum target based on variance-of-frequency weight

在线全文

学校读者我要写书评

暂无评论

一种基于频率方差加权的线谱目标检测方法

声学学报 2010年第1期35卷 76-80页

作者：陈阳王自娟朱代柱余赟惠俊英哈尔滨工程大学水声技术国防科技重点实验室哈尔滨150001 上海交通大学船舶海洋与建筑工程学院上海200240 上海船舶电子设备研究所上海201108

在复杂的多目标声场中,常规波束形成(CBF)检测器性能显著下降。本文提出一种基于频率方差加权的线谱目标检测方法——CBF频率方差检测器,利用被动目标辐射噪声中含有高强度的稳定线谱这一特征,用每个方位频率域的峰值频率方差对CBF输出... 详细信息

在复杂的多目标声场中,常规波束形成(CBF)检测器性能显著下降。本文提出一种基于频率方差加权的线谱目标检测方法——CBF频率方差检测器,利用被动目标辐射噪声中含有高强度的稳定线谱这一特征,用每个方位频率域的峰值频率方差对CBF输出的方位谱进行加权。该检测器可在多目标强干扰和同波束强相干干扰背景中检测到弱线谱目标,且只须三维显示,避开了传统的线谱检测四维显示的难点。仿真和海试结果表明,在多目标、强干扰的环境下,可以探测到弱线谱目标。

关键词：线谱检测频率方差目标检测加权方差检测器波束形成三维显示多目标