Ionospheric Tomography from a Reference GPS/MET Experiment Through the IRI Model

• Main Authors: Lung-Chih Tsai, Wei-Hsiung Tsai, Jan-Yin Chou, Chao-Han Liu
• Format: Article
• Language: English
• Published: Chinese Geoscience Union 2006-01-01
• Series: Terrestrial, Atmospheric and Oceanic Sciences
• Subjects: Ionospheric tomography; Total electron content (TEC); the Multiplicative Algebraic Reconstruction Technique (MART); GPS occultation
• Online Access: http://tao.cgu.org.tw/images/attachments/v171p263.pdf
• ISSN: 1017-0839; 2311-7680

In earlier studies, we implemented the Multiplicative Algebraic Reconstruction Technique (MART) to reconstruct two-dimensional ionospheric structures from measured TECs through the receptions of the GPS-to-LEO signals and/or the NNSS-to-ground beacon signals. To examine the accuracy of the reconstructed image we need ground-based validation systems which are difficult to obtain. However, such comparative investigation is needed if one aims to improve tomography inverse techniques and algorithms. In this study, we propose a simulation scheme to carry out this task. We first simulate the GPS-to-LEO TEC measurements through the IRI model by integrating electron densities along the ¡§straight¡¨ ray occultation paths between the GPS and LEO satellite obtained from the real GPS/MET experiment. Contiguous tomographic images are then derived by the MART algorithm within the ¡§reference¡¨ GPS/MET experiment. They are verified by comparison with the ¡§true¡¨ IRI-modelled ionosphere. We show that simulation/reference results can be used to find the optimal reconstruction strategy in space-based ionospheric tomography.