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基于数据协方差矩阵重构的MIMO声纳DOA估计 被引量:1
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作者 刘建涛 任岁玲 +2 位作者 姜永兴 章伟裕 徐鹏 《应用声学》 CSCD 北大核心 2017年第2期162-167,共6页
实际多输入多输出(MIMO)声纳系统由于环境或人为因素,可能出现部分阵元失效,从而导致阵列自由度减少、方位估计精度下降。本文提出了一种数据协方差矩阵重构方法,该方法基于差分阵列性质,利用正常工作阵元的协方差矩阵元素来恢复失效阵... 实际多输入多输出(MIMO)声纳系统由于环境或人为因素,可能出现部分阵元失效,从而导致阵列自由度减少、方位估计精度下降。本文提出了一种数据协方差矩阵重构方法,该方法基于差分阵列性质,利用正常工作阵元的协方差矩阵元素来恢复失效阵元的矩阵元素,获得满秩的数据协方差矩阵,从而恢复到全阵元MIMO声纳的阵列自由度。与已有方法相比,降低了计算复杂度。仿真及海试实验数据处理结果表明,本文所提的数据协方差矩阵重构方法能够恢复因部分阵元失效而丢失的阵列自由度,应用于方位估计中,所能分辨的最大目标数与全阵元相同。 展开更多
关键词 MIMO声纳 方位估计 阵元失效 数据协方差矩阵重构 自由度
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高效相干源DOA估计的ESPRIT新方法 被引量:1
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作者 蔡会甫 黄登山 《计算机应用研究》 CSCD 北大核心 2010年第1期314-316,共3页
ESPRIT算法是一种速度快、精度高的常用算法,但它不能解相干。针对此缺陷,提出了一种新的高效相干源DOA估计的改进ESPRTIT方法,新方法对数据协方差矩阵的最大特征值对应的特征向量按一定方式进行重排处理,以此来重构需要解相干矩阵。它... ESPRIT算法是一种速度快、精度高的常用算法,但它不能解相干。针对此缺陷,提出了一种新的高效相干源DOA估计的改进ESPRTIT方法,新方法对数据协方差矩阵的最大特征值对应的特征向量按一定方式进行重排处理,以此来重构需要解相干矩阵。它不仅解决了常规ESPRIT算法不能解相干的问题,同时相对常规ESPRIT算法计算过程大大简化。计算机仿真实验证明了该方法在解相干方面的良好性能,为解相干的ESPRIT算法在阵列信号处理的超高分辨领域开辟了新的途径。 展开更多
关键词 阵列信号处理 数据协方差矩阵 DOA估计 ESPRIT算法
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An Ocean Reanalysis System for the Joining Area of Asia and Indian-Pacific Ocean 被引量:9
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作者 YAN Chang-Xiang ZHU Jiang XIE Ji-Ping 《Atmospheric and Oceanic Science Letters》 2010年第2期81-86,共6页
An ocean reanalysis system for the joining area of Asia and Indian-Pacific Ocean (AIPO) has been developed and is currently delivering reanalysis data sets for study on the air-sea interaction over AIPO and its climat... An ocean reanalysis system for the joining area of Asia and Indian-Pacific Ocean (AIPO) has been developed and is currently delivering reanalysis data sets for study on the air-sea interaction over AIPO and its climate variation over China in the inter-annual time scale.This system consists of a nested ocean model forced by atmospheric reanalysis,an ensemble-based multivariate ocean data assimilation system and various ocean observations.The following report describes the main components of the data assimilation system in detail.The system adopts an ensemble optimal interpolation scheme that uses a seasonal update from a free running model to estimate the background error covariance matrix.In view of the systematic biases in some observation systems,some treatments were performed on the observations before the assimilation.A coarse resolution reanalysis dataset from the system is preliminarily evaluated to demonstrate the performance of the system for the period 1992 to 2006 by comparing this dataset with other observations or reanalysis data. 展开更多
关键词 reanalysis system data assimilation ensemble optimal interpolation background error covariance
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Principal Component Analysis (PCA) on Multivariate Data of Lard Analysis in Cooking Oil 被引量:1
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作者 Nor Aishah Mohd Salleh Mohd Sukri Hassan 《Journal of Mathematics and System Science》 2015年第7期300-306,共7页
Discrimination of fatty acids (FAs) of lard in used cooking oil is important in halal determination. The aim of this study was to find the information related to the changes FAs of lard when frying in cooking oil. Q... Discrimination of fatty acids (FAs) of lard in used cooking oil is important in halal determination. The aim of this study was to find the information related to the changes FAs of lard when frying in cooking oil. Quantitative analysis of FAs composition extracted from a series of experiments which involving frying cooking oil spiked with lard at three different parameters; concentration of spiked lard, heating temperatures and period of frying. The samples were analyzed using Gas Chromatography (GC) and Principal Components Analysis (PCA) technique. Multivariate data from chromatograms of FAs were standardized and computed using Unscrambler X10 into covariance matrix and eigenvectors correspond to Principal Components (PCs). Results have shown that the first and second PCs contribute to the FAs mapping which can be visualized by scores and loading plots to discriminate FAs of lard in used cooking oil 展开更多
关键词 Fatty acids LARD gas chromatography Principal Components Analysis
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