fan beam meaning in English
扇形波射束
扇形波束
扇形射束
Examples
- One has to set up a point source in the far field and rotate the system in the fan beam direction . the difficulty is mainly due to the incomplete test environment
但是，测量g矩阵不是一件很容易的工作，必须旋转仪器扫描远场的点源得到，测试条件要求比较苛刻。 - 2 . the design thought of annular fan beam sensor structure is presented , and array laser sensor of 15x5 fan beams structure was developed . the sensor ' s measurement sensitivity distribution and spatial resolution are analyzed and calculated
提出了环形扇束传感器结构的设计思想，并研制了15 5扇束结构的阵列式激光传感器，以及对其测量灵敏度分布和空间分辨率等性能指标进行了分析计算。 - In the terms of interpolation , the image reconstructed from nearest interpolation or linear interpolation has good edge but serious noise ; reconstruction from 4 * 4cubic interpolation or three b - spline or three - order lagrange interpolations has better local character . 2 x 2cubic interpolations which has both better edge and local character is the ideal interpolation , the following is the basic principle during reconstruction : ( 1 ) the more width of interpolation , the more number of summation and the more order of interpolation polynomial , the higher of density resolution ; ( 2 ) the more of interpolation polynomial and width of interpolation , the more of reconstruction time simultaneously , aimed at eliminating the effects of noise contained in projection data , in this paper , author analysis cause and effects of common artifacts . importantly , discusses convolution back - projection reconstruction algorithm with a shift axis of rotation has been derived for correcting images that acquired with a divergence axis of rotation using the fan beam geometry with an angle - equaled detector
在ct图像重建时，选择有限带宽窗有较好的空间分辨率，三角形窗有较好的密度分辨率，选择余弦窗则使得空间分辨率与密度分辨率的折衷；从窗函数的频谱角度来讲，可以用于图像重建的一个良好的卷积窗函数应该具备以下条件： ( ? )小的3db带宽b ，即最小的主瓣宽度； ( ? )最小的旁瓣最大峰值a ； ( ? )最大的旁瓣峰值衰减速度d ；就内插函数而言，临近点内插与线性内插重建图像噪声大，但有较好的边缘与细节； 4 4三次内插、三次b -样条与四次拉格朗日多项式内插图像平滑，局部特性较好。 - The simulation results show that , either for parallel geometry or for fan beam geometry , high resolution images can be reconstructed by means of both the algorithms from the overlapped projection data . moreover , the quality of the images reconstructed by the virtual detector algorithm from the overlapped low - resolution projection data is almost as good as that of the images reconstructed directly from the high - resolution projection data
大量模拟试验结果表明，无论对平行束的相叠低分辨数据还是对扇形束的相叠低分辨数据，用虚拟探测器法和直接重建法均可由相叠低分辨数据重建出具有较高分辨率的图像。 - The image reconstruction algorithms is thoroughly researched . the filter back projection ( fbp ) , algebra reconstruction technology ( art ) and fan beam data rearrangement algorithm used in medical computer tomography are improved . the noser algorithm , linear neural networks method and hopfield neural networks method are presented and gain the better result of image reconstruction
深入研究了图像重建算法，改进了医学ct的滤波反投影算法、代数重建技术和扇束投影数据重排方法，提出了带图像光滑约束的noser算法、线性神经网络方法和hopfield神经网络方法，并得到了较好的图像重建结果。