Based on the principle of statistics and the research results by Zhu Jianjun, the paper establishesthe mean Cook distance of scale parameter and studies its properties. The paper still presents the robust estimate of ...Based on the principle of statistics and the research results by Zhu Jianjun, the paper establishesthe mean Cook distance of scale parameter and studies its properties. The paper still presents the robust estimate of scale parameter with minimum mean Cook distance and theoretically shows that scale parameter isnot "nuisance parameter" and it determined by the plus weight squared sums of the residuals of observations.A simple numerical example is given.展开更多
This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna p...This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna patterns modeling of the phased array system is exploited to build the radar sweeping model and the signal propagation model. Secondly, the relationship between the variation of the radiated power and the antenna beam pointing angles in the given airspace is analyzed. Based on the above two points, the sample with obvious amplitude characteristics of the pulse amplitude train can be screened out after detecting the train peaks. Finally, the sample is matched to the subsequent pulse amplitude train based on the Hausdorff distance. The proposed methods have less prior knowledge and higher efficiency and are easier to process. By cross correlating the sample of the pulse amplitude train with the sample data of the antenna follow-up radiation, the probability of detection of the beam pointing direction becomes larger in case that the subsequent antenna beam returns to the specific position.展开更多
To increase the limited spatial processing gain of physical aperture of UUV(unmanned underwater vehicle) linear array and satisfy the demand of long distance target detection,a flank array based on the synthetic apert...To increase the limited spatial processing gain of physical aperture of UUV(unmanned underwater vehicle) linear array and satisfy the demand of long distance target detection,a flank array based on the synthetic aperture technique is introduced into UUV,and a modified beam domain passive synthetic aperture processing algorithm(BDPSA) suitable for the flank array is proposed concurrently,which sums the beamforming of linear array coherently for successive measurement after phase compensation to make the beam output peak corresponding to the expected target bearing,expand the array aperture effectively and improve the resolution.The simulation of detection probability and distinguishing probability for double targets within 1,1/2,1/3 and 1/4 beam-width shows that the method of BDPSA has lower SNR threshold for target distinguishing,improves the detection probability and distinguishing probability under low SNR,and realizes the long-distance and high resolution bearing estimation because of the obvious improvement of the spatial array gain.展开更多
Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case....Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case. A new robust method for the adjustment of geodetic networks is proposed. The suggested method, a generalization of the robust method with the minimum mean Cook distance, is more efficient than the others. The basic feature of the method is that the equivalent weight functions of the robust estimates are determined according to the principle of statistics.展开更多
L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正...L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。展开更多
通过分析基于交并比(Intersection over union,IoU)预测的尺度估计模型的梯度更新过程,发现其在训练和推理过程仅将IoU作为度量,缺乏对预测框和真实目标框中心点距离的约束,导致外观模型更新过程中模板受到污染,前景和背景分类时定位出...通过分析基于交并比(Intersection over union,IoU)预测的尺度估计模型的梯度更新过程,发现其在训练和推理过程仅将IoU作为度量,缺乏对预测框和真实目标框中心点距离的约束,导致外观模型更新过程中模板受到污染,前景和背景分类时定位出现偏差.基于此发现,构建了一种结合IoU和中心点距离的新度量NDIoU(Normalization distance IoU),在此基础上提出一种新的尺度估计方法,并将其嵌入判别式跟踪框架.即在训练阶段以NDIoU为标签,设计了具有中心点距离约束的损失函数监督网络的学习,在线推理期间通过最大化NDIoU微调目标尺度,以帮助外观模型更新时获得更加准确的样本.在七个数据集上与相关主流方法进行对比,所提方法的综合性能优于所有对比算法.特别是在GOT-10k数据集上,所提方法的AO、SR_(0.50)和SR_(0.75)三个指标达到了65.4%、78.7%和53.4%,分别超过基线模型4.3%、7.0%和4.2%.展开更多
文摘Based on the principle of statistics and the research results by Zhu Jianjun, the paper establishesthe mean Cook distance of scale parameter and studies its properties. The paper still presents the robust estimate of scale parameter with minimum mean Cook distance and theoretically shows that scale parameter isnot "nuisance parameter" and it determined by the plus weight squared sums of the residuals of observations.A simple numerical example is given.
基金supported by the National Natural Science Foundation of China(61501501)
文摘This paper presents a method to estimate beam pointing of phased array radar by the pulse amplitude train, which is significant in radar electronic reconnaissance and electronic support measure. Firstly, the antenna patterns modeling of the phased array system is exploited to build the radar sweeping model and the signal propagation model. Secondly, the relationship between the variation of the radiated power and the antenna beam pointing angles in the given airspace is analyzed. Based on the above two points, the sample with obvious amplitude characteristics of the pulse amplitude train can be screened out after detecting the train peaks. Finally, the sample is matched to the subsequent pulse amplitude train based on the Hausdorff distance. The proposed methods have less prior knowledge and higher efficiency and are easier to process. By cross correlating the sample of the pulse amplitude train with the sample data of the antenna follow-up radiation, the probability of detection of the beam pointing direction becomes larger in case that the subsequent antenna beam returns to the specific position.
文摘To increase the limited spatial processing gain of physical aperture of UUV(unmanned underwater vehicle) linear array and satisfy the demand of long distance target detection,a flank array based on the synthetic aperture technique is introduced into UUV,and a modified beam domain passive synthetic aperture processing algorithm(BDPSA) suitable for the flank array is proposed concurrently,which sums the beamforming of linear array coherently for successive measurement after phase compensation to make the beam output peak corresponding to the expected target bearing,expand the array aperture effectively and improve the resolution.The simulation of detection probability and distinguishing probability for double targets within 1,1/2,1/3 and 1/4 beam-width shows that the method of BDPSA has lower SNR threshold for target distinguishing,improves the detection probability and distinguishing probability under low SNR,and realizes the long-distance and high resolution bearing estimation because of the obvious improvement of the spatial array gain.
文摘Redefines the mean Cook distance under the contaminated error model. With the help of the mean Cook distance, the paper discusses the relationship between local influence of small perturbations and high leverage case. A new robust method for the adjustment of geodetic networks is proposed. The suggested method, a generalization of the robust method with the minimum mean Cook distance, is more efficient than the others. The basic feature of the method is that the equivalent weight functions of the robust estimates are determined according to the principle of statistics.
文摘L波段数字航空通信系统(L band digital aeronautical communication system,LDACS)是未来航空宽带通信重要的基础设施之一,针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment,DME)信号干扰的问题,提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival,DOA)估计方法。通过子空间投影抑制DME干扰,然后使用单快拍数据构建伪协方差矩阵,对伪协方差矩阵求高阶幂,之后进行奇异值分解,并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响,仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明,改进单快拍高级幂(improved single snapshot high order power,ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰,提高OFDM接收机性能。
文摘通过分析基于交并比(Intersection over union,IoU)预测的尺度估计模型的梯度更新过程,发现其在训练和推理过程仅将IoU作为度量,缺乏对预测框和真实目标框中心点距离的约束,导致外观模型更新过程中模板受到污染,前景和背景分类时定位出现偏差.基于此发现,构建了一种结合IoU和中心点距离的新度量NDIoU(Normalization distance IoU),在此基础上提出一种新的尺度估计方法,并将其嵌入判别式跟踪框架.即在训练阶段以NDIoU为标签,设计了具有中心点距离约束的损失函数监督网络的学习,在线推理期间通过最大化NDIoU微调目标尺度,以帮助外观模型更新时获得更加准确的样本.在七个数据集上与相关主流方法进行对比,所提方法的综合性能优于所有对比算法.特别是在GOT-10k数据集上,所提方法的AO、SR_(0.50)和SR_(0.75)三个指标达到了65.4%、78.7%和53.4%,分别超过基线模型4.3%、7.0%和4.2%.
