Prol Fabricio S, Camargo Paulo O, Muella Marcio T A H
Universidade Estadual Paulista/UNESP, Departamento de Cartografia, Rua Roberto Simonsen, 305, 19060-900 Presidente Prudente, SP, Brazil.
Universidade do Vale do Paraíba/UNIVAP, Laboratório de Física e Astronomia - IP&D, Rua Shishima Hifumi, 2911, 12244-000 São José dos Campos, SP, Brazil.
An Acad Bras Cienc. 2017 Jul-Sep;89(3):1531-1542. doi: 10.1590/0001-3765201720170116. Epub 2017 Jul 31.
The incomplete geometrical coverage of the Global Navigation Satellite System (GNSS) makes the ionospheric tomographic system an ill-conditioned problem for ionospheric imaging. In order to detect the principal limitations of the ill-conditioned tomographic solutions, numerical simulations of the ionosphere are under constant investigation. In this paper, we show an investigation of the accuracy of Algebraic Reconstruction Technique (ART) and Multiplicative ART (MART) for performing tomographic reconstruction of Chapman profiles using a simulated optimum scenario of GNSS signals tracked by ground-based receivers. Chapman functions were used to represent the ionospheric morphology and a set of analyses was conducted to assess ART and MART performance for estimating the Total Electron Content (TEC) and parameters that describes the Chapman function. The results showed that MART performed better in the reconstruction of the electron density peak and ART gave a better representation for estimating TEC and the shape of the ionosphere. Since we used an optimum scenario of the GNSS signals, the analyses indicate the intrinsic problems that may occur with ART and MART to recover valuable information for many applications of Telecommunication, Spatial Geodesy and Space Weather.
全球导航卫星系统（GNSS）的几何覆盖不完整，使得电离层层析成像系统在进行电离层成像时成为一个病态问题。为了检测病态层析成像解决方案的主要局限性，电离层的数值模拟一直在不断研究中。在本文中，我们展示了一项关于代数重建技术（ART）和乘法代数重建技术（MART）准确性的研究，该研究使用地面接收机跟踪的GNSS信号的模拟最佳场景来进行查普曼剖面的层析重建。查普曼函数用于表示电离层形态，并进行了一系列分析以评估ART和MART在估计总电子含量（TEC）以及描述查普曼函数的参数方面的性能。结果表明，MART在重建电子密度峰值方面表现更好，而ART在估计TEC和电离层形状方面表现更佳。由于我们使用了GNSS信号的最佳场景，这些分析表明了ART和MART在为电信、空间大地测量和空间天气等许多应用恢复有价值信息时可能出现的固有问题。
