Japan Geoscience Union Meeting 2015

Presentation information

International Session (Oral)

Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

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

Tue. May 26, 2015 4:15 PM - 6:00 PM A01 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Huixin Liu(Earth and Planetary Science Division, Kyushu University SERC, Kyushu University), Yuichi Otsuka(Solar-Terrestrial Environment Laboratory, Nagoya University), Libo Liu(Institute of Geology and Geophysics, Chinese Academy of Sciences), Atsuki Shinbori(Research Institute for Sustainable Humanosphere (RISH), Kyoto University), Chair:Yuichi Otsuka(Solar-Terrestrial Environment Laboratory, Nagoya University)

5:58 PM - 6:00 PM

[PEM06-P06] Development of real-time three-dimensional GPS-TEC tomography

3-min talk in an oral session

*Shota SUZUKI1, Mamoru YAMAMOTO1, Chieh-Hung Chen2, Susumu SAITO3, Gopi Seemala1, Akinori SAITO4 (1.Research Institute for Sustainable Humanosphere, Kyoto University, 2.Department of Earth and Environmental Sciences, National Chung Cheng University, Taiwan, 3.Department of Geophysics, Graduate School of Science, Kyoto University, 4.Navigation Systems Department, Electronic Navigation Research Institute)

Keywords:GEONET, TEC, tomography, sparse matrix, real-time system

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.