CAJ | 학술논문

本文是利用计算机断层成像(CT)方法中的滤波反投影法(FBP)和代数迭代法(ART),根据等离子体层的仿真模型,重建其全球密度分布.在重建过程中,地球遮挡足一个很重要的问题.计算结果表明两种方法都可以使用,但ART比FBP重建的效果好.ART重建图像的相关系数可达0.98,而FBP重建图像的相关系数仅为0.86.FBP重建的偏差是由地球遮挡引起,向阳面靠近地球区域的密度会减小.从定量分析中可以进一步看出地球遮挡所引起的偏差变化.
본문시이용계산궤단층성상(CT)방법중적려파반투영법(FBP)화대수질대법(ART),근거등리자체층적방진모형,중건기전구밀도분포.재중건과정중,지구차당족일개흔중요적문제.계산결과표명량충방법도가이사용,단ART비FBP중건적효과호.ART중건도상적상관계수가체0.98,이FBP중건도상적상관계수부위0.86.FBP중건적편차시유지구차당인기,향양면고근지구구역적밀도회감소.종정량분석중가이진일보간출지구차당소인기적편차변화.
The deduction of the global density of Earth plasmasphere from the column density of the plasmasphere is studied by using Computed Tomography (CT) technique,which has been achieved by the well-known Filtered Back Projection (FBP).Due to the Earth's shelter,using this method,there will be a gradual deviation from the original Phantom Diagram especially in the dayside area near the Earth,and this deviation can be acknowledged through further quantitative analysis. An improved accuracy of reconstruction is achieved by using the Algebraic Reconstruction Technique (ART). Their reconstruction quality has been analyzed through the correlation coefficient:between the Phantom Diagram and the reconstruction results,the value of ART approach is 0.98 while FBP approach is only 0.86. The result has established that the ART is more efficient than the FBP when the Phantom Diagram includes Earth's shelter.