超分辨雷达成像方法不受瑞利限的限制,可以极大地提高雷达距离维分辨率,利于目标识别。针对传统方法不具有频率选择性,研究了一种基于时域预滤波旋转不变参数估计技术(EISPRIT:Estimation of Signal Parameter via RotationalInvariance...超分辨雷达成像方法不受瑞利限的限制,可以极大地提高雷达距离维分辨率,利于目标识别。针对传统方法不具有频率选择性,研究了一种基于时域预滤波旋转不变参数估计技术(EISPRIT:Estimation of Signal Parameter via RotationalInvariance Techniques)的超分辨谱估计新方法,并成功应用于雷达距离维成像中。该算法把具有频率选择性的时域预滤波器和拓展旋转不变参数估计技术相结合。首先对雷达信号进行粗谱分析,获得信号频率分布的先验信息,然后针对性地设计频率选择时域滤波器对原始回波进行预处理,提高ESPRIT方法在目标信号所处频段的谱估计精度,改善距离维成像质量。仿真实验和暗室数据成像结果表明该方法具有频率选择特性和更好的频谱估计精度。展开更多
Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased ac...Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased accuracy and precision in the delivery of dose.While these developments are well established since a fairly long time for external beam radiotherapy,they are yet to be firmly established in many brachytherapy units all over the world particularly in the developing countries.We will review the basic principles of image-based brachytherapy and explore the potential clinical opportunities behind this innovative technique.展开更多
In this article the problem of three-dimensional （3-D） reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser ran...In this article the problem of three-dimensional （3-D） reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser range finder imaging system for better optimization of maximum range detection with a given SNR （Signal-to-noise ratio）. The study proposes a new reformulation of the radiometric Gaussian beam range equation on the basis of the photodetector active area. The adjustment of the optical and geometrical characteristics of the laser range finder so defined can be used to minimize the signal span to avoid the saturation of the detector cell and improve the ranging measurements （accuracy and range） for a 3D imaging application.展开更多
文摘超分辨雷达成像方法不受瑞利限的限制,可以极大地提高雷达距离维分辨率,利于目标识别。针对传统方法不具有频率选择性,研究了一种基于时域预滤波旋转不变参数估计技术(EISPRIT:Estimation of Signal Parameter via RotationalInvariance Techniques)的超分辨谱估计新方法,并成功应用于雷达距离维成像中。该算法把具有频率选择性的时域预滤波器和拓展旋转不变参数估计技术相结合。首先对雷达信号进行粗谱分析,获得信号频率分布的先验信息,然后针对性地设计频率选择时域滤波器对原始回波进行预处理,提高ESPRIT方法在目标信号所处频段的谱估计精度,改善距离维成像质量。仿真实验和暗室数据成像结果表明该方法具有频率选择特性和更好的频谱估计精度。
文摘Imaging is now a well established component of radiation therapy with all major imaging modalities represented and numerous examples in which these modalities have been used in treatment planning to allow increased accuracy and precision in the delivery of dose.While these developments are well established since a fairly long time for external beam radiotherapy,they are yet to be firmly established in many brachytherapy units all over the world particularly in the developing countries.We will review the basic principles of image-based brachytherapy and explore the potential clinical opportunities behind this innovative technique.
文摘In this article the problem of three-dimensional （3-D） reconstruction of scenes from terrestrial laser rangefinder data is processed, we present the simulations results of radiometric range function of the laser range finder imaging system for better optimization of maximum range detection with a given SNR （Signal-to-noise ratio）. The study proposes a new reformulation of the radiometric Gaussian beam range equation on the basis of the photodetector active area. The adjustment of the optical and geometrical characteristics of the laser range finder so defined can be used to minimize the signal span to avoid the saturation of the detector cell and improve the ranging measurements （accuracy and range） for a 3D imaging application.
