Temporal variations of ionospheric electron-density （IED） distributions over China are inversed by applying the computerized ionospheric tomography （CIT） technique to dual-frequency GPS data of the Crustal Movemen...Temporal variations of ionospheric electron-density （IED） distributions over China are inversed by applying the computerized ionospheric tomography （CIT） technique to dual-frequency GPS data of the Crustal Movement Observation Network of China （CMONOC） in 2003. Characteristics of the diurnal variations of IED, especially the development and disappearance of the equatorial anomaly structure and the variations of the ionospheric vertical structure, are investigated. The result shows that it is feasible to sound and investigate the temporal-spatial variations of lED by using CIT technique and the high-accuracy GPS data, but the accuracy and reliability are limited by insufficiency of GPS data, reconstruction methods, and CIT models.展开更多
提出了一种基于截断奇异值分解正则化(Truncated Singular Value Decomposition,TSVD)的电离层层析成像算法.该算法选择球谐函数与经验正交函数作为表征电离层电子密度空间变化的基函数,以降低背景模型对层析成像的影响;利用广义交叉验...提出了一种基于截断奇异值分解正则化(Truncated Singular Value Decomposition,TSVD)的电离层层析成像算法.该算法选择球谐函数与经验正交函数作为表征电离层电子密度空间变化的基函数,以降低背景模型对层析成像的影响;利用广义交叉验证法来选择合适的截断参数,提高了算法的稳定性和反演精度.基于中国区域23个观测站的电离层层析成像仿真结果表明:与乘法代数重构算法(Multiplicative Algebraic Reconstruction Technique,MART)相比,基于TSVD正则化的电离层层析成像算法能够在不需要背景电离层电子密度作为先验条件的情况下,实现电离层电子密度的有效反演.展开更多
基金sapported by the Program for New Century Excellent Talents in University(NCET)the National Natural Science Foundation of China(40804002)the Scientific Research Foundation of Hunan Provincial Education Department(09B007)
文摘Temporal variations of ionospheric electron-density （IED） distributions over China are inversed by applying the computerized ionospheric tomography （CIT） technique to dual-frequency GPS data of the Crustal Movement Observation Network of China （CMONOC） in 2003. Characteristics of the diurnal variations of IED, especially the development and disappearance of the equatorial anomaly structure and the variations of the ionospheric vertical structure, are investigated. The result shows that it is feasible to sound and investigate the temporal-spatial variations of lED by using CIT technique and the high-accuracy GPS data, but the accuracy and reliability are limited by insufficiency of GPS data, reconstruction methods, and CIT models.
