An iterative algorithm to calculate mutual correlation using hierarchical key points and the search space mark principle is proposed. An effective algorithm is designed to improve the matching speed. By hi-erarchical ...An iterative algorithm to calculate mutual correlation using hierarchical key points and the search space mark principle is proposed. An effective algorithm is designed to improve the matching speed. By hi-erarchical key point algorithm and mutual correlation coefficients of the matching images, the important points can be iteratively calculated in the images hierarchically, and the correlation coefficient can be ob-tained with satisfactory precision. Massive spots in the parameter space which are impossible to match can be removed by the search space mark principle. Two approximate continuities in the correlation image matching process, the image gray level distribution continuity and the correlation coefficient value in the parameter space continuity, are considered in the method. The experiments show that the new algorithm can greatly enhance matching speed and achieve accurate matching results.展开更多
在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)...在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)信号进行常规跟踪时,虽然能获取大时宽带宽积提升距离分辨率,但脉冲压缩后产生的强距离多普勒耦合效应使传统的距离速度测量算法出现收敛速度慢、精度低的问题,尤其在航迹起始阶段对高速目标的跟踪极为不利,严重影响了雷达系统对目标的实时、精准监测。提出一种多普勒距离耦合下的三帧快速收敛算法。该算法利用3帧具有不同耦合系数的波形,构建多元约束方程,通过联合解算实现多目标速度和位置参数的同步获取。在验证处理流程中,采用迭代优化机制,对测量结果进行动态校准,有效降低距离与速度参数间的相互干扰,逐步逼近最优的距离和速度测量结果,从而实现快速、精准的目标跟踪。通过理论分析、蒙特卡罗仿真和外场实测数据验证,该三帧快速收敛算法展现出优异性能。在航迹起始阶段,对目标距离和速度测量解算的收敛速度是传统算法的4倍以上。所提出的多普勒距离耦合下的三帧快速收敛算法成功地解决了传统算法在处理多普勒距离耦合问题时存在的收敛慢、精度低等难题。该算法具有创新的波形设计和迭代优化策略,显著提升了相控阵雷达在复杂条件下的目标跟踪性能,为雷达目标跟踪技术的发展提供了新的思路和方法,具有较高的理论价值和实际应用前景。展开更多
Two new versions of accelerated first-order methods for minimizing convex composite functions are proposed. In this paper, we first present an accelerated first-order method which chooses the step size 1/ Lk to be 1/ ...Two new versions of accelerated first-order methods for minimizing convex composite functions are proposed. In this paper, we first present an accelerated first-order method which chooses the step size 1/ Lk to be 1/ L0 at the beginning of each iteration and preserves the computational simplicity of the fast iterative shrinkage-thresholding algorithm. The first proposed algorithm is a non-monotone algorithm. To avoid this behavior, we present another accelerated monotone first-order method. The proposed two accelerated first-order methods are proved to have a better convergence rate for minimizing convex composite functions. Numerical results demonstrate the efficiency of the proposed two accelerated first-order methods.展开更多
In order to obtain and master the surface thermal deformation of paraboloid antennas,a fast iterative closest point( FICP) algorithm based on design coordinate guidance is proposed,which can satisfy the demands of rap...In order to obtain and master the surface thermal deformation of paraboloid antennas,a fast iterative closest point( FICP) algorithm based on design coordinate guidance is proposed,which can satisfy the demands of rapid detection for surface thermal deformation. Firstly,the basic principle of the ICP algorithm for registration of a free surface is given,and the shortcomings of the ICP algorithm in the registration of surface are analysed,such as its complex computation,long calculation time,low efficiency,and relatively strict initial registration position. Then an improved FICP algorithm based on design coordinate guidance is proposed. Finally,the FICP algorithm is applied to the fast registration test for the surface thermal deformation of a paraboloid antenna. Results indicate that the approach offers better performance with regard to fast surface registration and the algorithm is more simple,efficient,and easily realized in practical engineering application.展开更多
基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提...基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提出基于函数波束形成的改进FFT-FISTA算法。改进算法以函数波束形成输出作为FFT-FISTA算法的迭代输入,建立函数波束形成、声源分布及升幂空间转移不变点扩散函数的线性方程组,基于周期边界条件下的快速傅里叶变换进行迭代求解,使被运算的非周期函数变为一个周期函数,解决补零边界带来的波数泄漏问题,可提高运算准确性,进一步提升成像性能;通过指数运算锐化点扩散函数主瓣,拓展点扩散函数空间转移不变性假设的适用性。仿真和试验结果表明,相较于常规FFT-FISTA算法,改进算法能提升成像空间分辨率及动态范围,扩大FFT-FISTA算法的有效成像区域,压缩气体泄漏试验结果验证了改进算法的有效性。展开更多
文摘An iterative algorithm to calculate mutual correlation using hierarchical key points and the search space mark principle is proposed. An effective algorithm is designed to improve the matching speed. By hi-erarchical key point algorithm and mutual correlation coefficients of the matching images, the important points can be iteratively calculated in the images hierarchically, and the correlation coefficient can be ob-tained with satisfactory precision. Massive spots in the parameter space which are impossible to match can be removed by the search space mark principle. Two approximate continuities in the correlation image matching process, the image gray level distribution continuity and the correlation coefficient value in the parameter space continuity, are considered in the method. The experiments show that the new algorithm can greatly enhance matching speed and achieve accurate matching results.
文摘在雷达目标跟踪领域,当目标与雷达传感器存在相对运动时,多普勒(Doppler)效应致使接收信号产生频率偏移。这种频率变化与目标距离测量存在耦合关系,即多普勒距离耦合问题。在相控阵雷达采用线性调频(Linear Frequency Modulation,LFM)信号进行常规跟踪时,虽然能获取大时宽带宽积提升距离分辨率,但脉冲压缩后产生的强距离多普勒耦合效应使传统的距离速度测量算法出现收敛速度慢、精度低的问题,尤其在航迹起始阶段对高速目标的跟踪极为不利,严重影响了雷达系统对目标的实时、精准监测。提出一种多普勒距离耦合下的三帧快速收敛算法。该算法利用3帧具有不同耦合系数的波形,构建多元约束方程,通过联合解算实现多目标速度和位置参数的同步获取。在验证处理流程中,采用迭代优化机制,对测量结果进行动态校准,有效降低距离与速度参数间的相互干扰,逐步逼近最优的距离和速度测量结果,从而实现快速、精准的目标跟踪。通过理论分析、蒙特卡罗仿真和外场实测数据验证,该三帧快速收敛算法展现出优异性能。在航迹起始阶段,对目标距离和速度测量解算的收敛速度是传统算法的4倍以上。所提出的多普勒距离耦合下的三帧快速收敛算法成功地解决了传统算法在处理多普勒距离耦合问题时存在的收敛慢、精度低等难题。该算法具有创新的波形设计和迭代优化策略,显著提升了相控阵雷达在复杂条件下的目标跟踪性能,为雷达目标跟踪技术的发展提供了新的思路和方法,具有较高的理论价值和实际应用前景。
基金Sponsored by the National Natural Science Foundation of China(Grant No.11461021)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2017JM1014)
文摘Two new versions of accelerated first-order methods for minimizing convex composite functions are proposed. In this paper, we first present an accelerated first-order method which chooses the step size 1/ Lk to be 1/ L0 at the beginning of each iteration and preserves the computational simplicity of the fast iterative shrinkage-thresholding algorithm. The first proposed algorithm is a non-monotone algorithm. To avoid this behavior, we present another accelerated monotone first-order method. The proposed two accelerated first-order methods are proved to have a better convergence rate for minimizing convex composite functions. Numerical results demonstrate the efficiency of the proposed two accelerated first-order methods.
基金Supported by the National Natural Science Foundation of China(No.51474217,41501562)the Open Fund Program of Henan Engineering Laboratory of Pollution Control and Coal Chemical Resources Comprehensive Utilization(No.502002-B07,502002-A04)
文摘In order to obtain and master the surface thermal deformation of paraboloid antennas,a fast iterative closest point( FICP) algorithm based on design coordinate guidance is proposed,which can satisfy the demands of rapid detection for surface thermal deformation. Firstly,the basic principle of the ICP algorithm for registration of a free surface is given,and the shortcomings of the ICP algorithm in the registration of surface are analysed,such as its complex computation,long calculation time,low efficiency,and relatively strict initial registration position. Then an improved FICP algorithm based on design coordinate guidance is proposed. Finally,the FICP algorithm is applied to the fast registration test for the surface thermal deformation of a paraboloid antenna. Results indicate that the approach offers better performance with regard to fast surface registration and the algorithm is more simple,efficient,and easily realized in practical engineering application.
文摘基于快速傅里叶变换的快速迭代收缩阈值算法(fast iterative shrinkage threshold algorithm based on fast Fourier transform, FFT-FISTA)具有较高的计算效率,但其忽略点扩散函数的空间变化及卷绕误差,造成声源识别性能的损失,为此提出基于函数波束形成的改进FFT-FISTA算法。改进算法以函数波束形成输出作为FFT-FISTA算法的迭代输入,建立函数波束形成、声源分布及升幂空间转移不变点扩散函数的线性方程组,基于周期边界条件下的快速傅里叶变换进行迭代求解,使被运算的非周期函数变为一个周期函数,解决补零边界带来的波数泄漏问题,可提高运算准确性,进一步提升成像性能;通过指数运算锐化点扩散函数主瓣,拓展点扩散函数空间转移不变性假设的适用性。仿真和试验结果表明,相较于常规FFT-FISTA算法,改进算法能提升成像空间分辨率及动态范围,扩大FFT-FISTA算法的有效成像区域,压缩气体泄漏试验结果验证了改进算法的有效性。
