日本地球惑星科学連合2015年大会

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インターナショナルセッション(ポスター発表)

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM06] Mesosphere-Thermosphere-Ionosphere Coupling in the Earth's Atmosphere

2015年5月26日(火) 18:15 〜 19:30 コンベンションホール (2F)

コンビーナ:*Huixin Liu(九州大学理学研究院地球惑星科学専攻 九州大学宙空環境研究センター)、大塚 雄一(名古屋大学太陽地球環境研究所)、Libo Liu(Institute of Geology and Geophysics, Chinese Academy of Sciences)、新堀 淳樹(京都大学生存圏研究所)

18:15 〜 19:30

[PEM06-P06] リアルタイムGPS-TEC3次元トモグラフィの開発

*鈴木 翔大1山本 衛1Chieh-Hung Chen2斎藤 享3Gopi Seemala1齊藤 昭則4 (1.京都大学生存圏研究所、2.Department of Earth and Environmental Sciences, National Chung Cheng University, Taiwan、3.京都大学大学院理学研究科地球物理学教室、4.電子航法研究所航法システム領域)

キーワード:ジオネット, 全電子数, トモグラフィ, 疎行列, リアルタイムシステム

Recently, a new three-dimensional GPS ionospheric tomography technique is developed which uses total electron content (TEC) data from the dense GPS receiver network, GPS Earth Observation Network (GEONET) in Japan. It uses the least squares fitting method constrained by the spatial gradient, and does not require an ionospheric model as the initial guess that could bias the reconstruction of electron density. But it refers to the NeQuick model to determine constrained parameters. The purpose of this study is to develop this technique and incorporate into the real-time GPS-TEC monitoring system. First we increase the computation speed by using a sparse matrix algorithm when solving the least squares fitting method. Programmed with Python, it takes less than 5 minutes to calculate a tomography by using 1.7GHz Intel Core i7. We could also improve the stability of the calculation. Furthermore we try to find a new method for determining the constrained parameters by analyzing a large amount data. As the tomography uses absolute TEC, it is necessarily to estimate instrumental delay bias which is originated in the hardware of the GPS satellite and receiver. We develop the bias estimation procedure that uses RINEX-OBS data of the previous day. Organizing these parts, we develop a system to conduct three-dimensional tomography analysis in the real-time basis.