We observed a phenomenon that different scattering components have different decorrelation time.Based on decorrelation time difference,we proposed a method to image an object hidden behind a turbid medium in a reflect...We observed a phenomenon that different scattering components have different decorrelation time.Based on decorrelation time difference,we proposed a method to image an object hidden behind a turbid medium in a reflection mode.In order to suppress the big disturbance calused by reflection and back scattering,two framnes of speckles are recorded in sequence,and their difference is used for image reconstruction.Our method is immune to both medium motions and object movements.展开更多
This paper develops a temporal decorrelation model for the bistatic synthetic aperture radar（BSAR） interferometry. The temporal baseline is one of the important decorrelation sources for the repeat-pass synthetic ap...This paper develops a temporal decorrelation model for the bistatic synthetic aperture radar（BSAR） interferometry. The temporal baseline is one of the important decorrelation sources for the repeat-pass synthetic aperture radar（SAR） interferometry. The study of temporal decorrelation is challenging, especially for the bistatic configuration, since temporal decorrelation is related to the data acquisition geometry. To develop an appropriate theoretical model for BSAR interferometry, the existing models for monostatic SAR cases are extended, and the general BSAR geometry configuration is involved in the derivation. Therefore, the developed temporal decorrelation model can be seen as a general model.The validity of the theoretical model is supported by Monte Carlo simulations. Furthermore, the impacts of the system parameters and BSAR geometry configurations on the temporal decorrelation model are discussed briefly.展开更多
In order to alleviate the shortcomings of most blind deconvolution algorithms,this paper proposes an improved fast algorithm for blind deconvolution based on decorrelation technique and broadband block matrix.Althougt...In order to alleviate the shortcomings of most blind deconvolution algorithms,this paper proposes an improved fast algorithm for blind deconvolution based on decorrelation technique and broadband block matrix.Althougth the original algorithm can overcome the shortcomings of current blind deconvolution algorithms,it has a constraint that the number of the source signals must be less than that of the channels.The improved algorithm deletes this constraint by using decorrelation technique.Besides,the improved algorithm raises the separation speed in terms of improving the computing methods of the output signal matrix.Simulation results demonstrate the validation and fast separation of the improved algorithm.展开更多
Variations of glaciers are important parameters for monitoring glacial change. Although optical remote sensing method can extract variations of glaciers effectively and accurately in cloudless regions, these variation...Variations of glaciers are important parameters for monitoring glacial change. Although optical remote sensing method can extract variations of glaciers effectively and accurately in cloudless regions, these variations are difficult to extract in cloudy conditions and bad weather. In this paper, a new method is presented, based on the decorrelation of repeat SAR interferometry, to extract the variations of glaciers. This method uses the decorrelation of the inland glacier＇s surface to extract the variation of glacier by comparing the coherence of the glacier and land cover in threshold values. For validation of this method, we compared classification results with that derived from TM images. An accuracy of better than 89% can be achieved if we consider the classification result from TM image as the ground truth. Results show that this method provides an effective way to identify icy areas from the coherent image.展开更多
In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before de...In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before decision to mitigate their interferences. As a result, this decorrelator is a linear detector and does not need any amplitude information of users as in decision-feedback detectors. Compared with existing 'one-shot' decorrelator, it has reduced complexity and provided better performance while eliminating all Multiple Access Interference(MAI). The performance of this decorrelator is analyzed thoeritically, and analytical result is given. Numerical results show near-far resistant capability of this decorrelator in both AWGN and fading channel.展开更多
现有的对比深度图聚类方法严重依赖输入图的同配性假设,在异配图中容易引发负采样假阴性与特征冗余的问题,导致聚类性能下降.为此,文中提出基于无负采样与权重去相关对比网络的图无关聚类方法(Negative-Free and Weight-Decorrelated Co...现有的对比深度图聚类方法严重依赖输入图的同配性假设,在异配图中容易引发负采样假阴性与特征冗余的问题,导致聚类性能下降.为此,文中提出基于无负采样与权重去相关对比网络的图无关聚类方法(Negative-Free and Weight-Decorrelated Contrastive Network for Graph-Agnostic Clustering,NFWD).首先,利用节点属性相似性构建特征图作为补充视图,通过拉普拉斯平滑滤波与共享参数的多层感知机(Multilayer Perceptron,MLP)分别获得特征图和原始图的节点表示,缓解同配性假设的原始图依赖.然后,针对异配图类冲突导致的负采样假阴性问题,基于自适应融合的节点表示获取聚类信息,构建簇中心节点表示,设计有效解决此问题的节点级与簇级双重特征对比的无负采样策略.最后,对MLP的权重矩阵施加正交约束,主动抑制冗余特征产生.在6个基准图数据集上的实验表明NFWD在图无关场景中的高效性与鲁棒性.展开更多
为了在视域(field of view,FOV)不同的条件下实现对数量时变的不确定目标的最优跟踪,提出一种高斯混合概率假设密度(Gaussian mixture probability hypothesis density,GM-PHD)滤波器的去相关算术平均(arithmetic average,AA)融合算法...为了在视域(field of view,FOV)不同的条件下实现对数量时变的不确定目标的最优跟踪,提出一种高斯混合概率假设密度(Gaussian mixture probability hypothesis density,GM-PHD)滤波器的去相关算术平均(arithmetic average,AA)融合算法。鉴于多目标AA融合被分解为多组单目标分量的合并,先通过重构贝叶斯融合推导出最优去相关估计融合,后将其用作单目标分量的合并方法。由于推导的去相关估计融合需要先验估计,设计了一个包含主滤波器的分层结构,以自动提供需要的先验估计。为了解决不同FOV导致的目标势低估问题,融合节点利用FOV补偿单目标分量的权重。仿真结果证实了提出的算法在各种场景中的最优性,提升了多目标跟踪的精度。展开更多
文摘We observed a phenomenon that different scattering components have different decorrelation time.Based on decorrelation time difference,we proposed a method to image an object hidden behind a turbid medium in a reflection mode.In order to suppress the big disturbance calused by reflection and back scattering,two framnes of speckles are recorded in sequence,and their difference is used for image reconstruction.Our method is immune to both medium motions and object movements.
基金supported by the National Natural Science Foundation of China(6110117861271441)
文摘This paper develops a temporal decorrelation model for the bistatic synthetic aperture radar（BSAR） interferometry. The temporal baseline is one of the important decorrelation sources for the repeat-pass synthetic aperture radar（SAR） interferometry. The study of temporal decorrelation is challenging, especially for the bistatic configuration, since temporal decorrelation is related to the data acquisition geometry. To develop an appropriate theoretical model for BSAR interferometry, the existing models for monostatic SAR cases are extended, and the general BSAR geometry configuration is involved in the derivation. Therefore, the developed temporal decorrelation model can be seen as a general model.The validity of the theoretical model is supported by Monte Carlo simulations. Furthermore, the impacts of the system parameters and BSAR geometry configurations on the temporal decorrelation model are discussed briefly.
基金Natural Science Fund of Anhui Province of China (050420101)
文摘In order to alleviate the shortcomings of most blind deconvolution algorithms,this paper proposes an improved fast algorithm for blind deconvolution based on decorrelation technique and broadband block matrix.Althougth the original algorithm can overcome the shortcomings of current blind deconvolution algorithms,it has a constraint that the number of the source signals must be less than that of the channels.The improved algorithm deletes this constraint by using decorrelation technique.Besides,the improved algorithm raises the separation speed in terms of improving the computing methods of the output signal matrix.Simulation results demonstrate the validation and fast separation of the improved algorithm.
基金supported by funds from 973 Program (No.2009CB723901)863 Program (No. 2009AA12Z122)863 Program (No. 2008AA12Z145)
文摘Variations of glaciers are important parameters for monitoring glacial change. Although optical remote sensing method can extract variations of glaciers effectively and accurately in cloudless regions, these variations are difficult to extract in cloudy conditions and bad weather. In this paper, a new method is presented, based on the decorrelation of repeat SAR interferometry, to extract the variations of glaciers. This method uses the decorrelation of the inland glacier＇s surface to extract the variation of glacier by comparing the coherence of the glacier and land cover in threshold values. For validation of this method, we compared classification results with that derived from TM images. An accuracy of better than 89% can be achieved if we consider the classification result from TM image as the ground truth. Results show that this method provides an effective way to identify icy areas from the coherent image.
文摘In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before decision to mitigate their interferences. As a result, this decorrelator is a linear detector and does not need any amplitude information of users as in decision-feedback detectors. Compared with existing 'one-shot' decorrelator, it has reduced complexity and provided better performance while eliminating all Multiple Access Interference(MAI). The performance of this decorrelator is analyzed thoeritically, and analytical result is given. Numerical results show near-far resistant capability of this decorrelator in both AWGN and fading channel.
文摘现有的对比深度图聚类方法严重依赖输入图的同配性假设,在异配图中容易引发负采样假阴性与特征冗余的问题,导致聚类性能下降.为此,文中提出基于无负采样与权重去相关对比网络的图无关聚类方法(Negative-Free and Weight-Decorrelated Contrastive Network for Graph-Agnostic Clustering,NFWD).首先,利用节点属性相似性构建特征图作为补充视图,通过拉普拉斯平滑滤波与共享参数的多层感知机(Multilayer Perceptron,MLP)分别获得特征图和原始图的节点表示,缓解同配性假设的原始图依赖.然后,针对异配图类冲突导致的负采样假阴性问题,基于自适应融合的节点表示获取聚类信息,构建簇中心节点表示,设计有效解决此问题的节点级与簇级双重特征对比的无负采样策略.最后,对MLP的权重矩阵施加正交约束,主动抑制冗余特征产生.在6个基准图数据集上的实验表明NFWD在图无关场景中的高效性与鲁棒性.
文摘为了在视域(field of view,FOV)不同的条件下实现对数量时变的不确定目标的最优跟踪,提出一种高斯混合概率假设密度(Gaussian mixture probability hypothesis density,GM-PHD)滤波器的去相关算术平均(arithmetic average,AA)融合算法。鉴于多目标AA融合被分解为多组单目标分量的合并,先通过重构贝叶斯融合推导出最优去相关估计融合,后将其用作单目标分量的合并方法。由于推导的去相关估计融合需要先验估计,设计了一个包含主滤波器的分层结构,以自动提供需要的先验估计。为了解决不同FOV导致的目标势低估问题,融合节点利用FOV补偿单目标分量的权重。仿真结果证实了提出的算法在各种场景中的最优性,提升了多目标跟踪的精度。
