Project/Area Number |
12554016
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
Space and upper atmospheric physics
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Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
YAMAMOTO M Kyoto University, Radio Science Center for Space and Atmosphere, Associate Professor, 宙空電波科学研究センター, 助教授 (20210560)
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Co-Investigator(Kenkyū-buntansha) |
OTSUKA Y Nagoya University, Solar-Terrestrial Environment Laboratory, Research Associate, 太陽地球環境研究所, 助手 (40314025)
IYEMORII T Kyoto University, Data Analysis Center for Geomagnetism and Space Magnetism, Professor, 大学院・理学研究科附属地磁気世界資料解析センター, 教授 (40144315)
FUKAO S Kyoto University, Radio Science Center for Space and Atmosphere, Professor, 宙空電波科学研究センター, 教授 (30026249)
宮崎 真一 国土地理院, 地理地殻活動研究センター, 研究員
OGAWA T Nagoya University, Solar-Terrestrial Environment Laboratory, Professor, 太陽地球環境研究所, 教授 (60271607)
MIYAZAKI S Geographical Survey Institute, Research Scientist
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Project Period (FY) |
2000 – 2001
|
Project Status |
Completed (Fiscal Year 2001)
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Budget Amount *help |
¥9,700,000 (Direct Cost: ¥9,700,000)
Fiscal Year 2001: ¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2000: ¥6,000,000 (Direct Cost: ¥6,000,000)
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Keywords | GPS / Ionosphere / TEC / GEONET / Data base / TID / Totale Electron Content / 中緯度電離圏 / 電離圏全電子数 / 電離圏伝搬性擾乱 / GPS受信機網 / GPS-TEC / TECデータベース / FRONTキャンペーン |
Research Abstract |
A system to derive and distribute Total Electron Content (TEC) data over Japan was developed using the observational data of GEONET, a GPS receiver network operated by Geographical Survey Institute. GEONET obtains positioning data from GPS satellites in every 30 seconds at about 1000 receivers. The observed positioning data were converted to vertical TEC considering the geometry between the line-of-sight and the ionosphere. To reduce errors caused by this conversion, the data with low elevation angles were omitted in this process. Using this GEONET TEC data, two-dimensional distribution of TEC over Japan was derived with 30 seconds of temporal resolution and 0.15 degrees of spatial resolution in latitude and longitude. The accuracy of the derived TEC was estimated to be 2-4x10^<16> electron/m^2. Electrical biases inside of the transmitters and receivers were estimated and subtracted from the observed TEC data with the least-square fitting method. All of GEONET data since April in 1999
… More
were processed with this method and newly obtained data are also processed every day. The derived TEC data are stored in a data base and can be accessed through WWW at http://stegps.kugi.kyoto-u.ac.jp/. Four types of data are provided in this data base : ATEC (absolute value of TEC for each receiver), TEC (TEC data for each receiver containing biases), AGRJD (two-dimensional distribution of absolute TEC over Japan) and GRID (two-dimensional distribution of perturbation TEC). Two-dimensional maps of TEC are also stored in the data base. The data base has interactive plot pages to make plots of TEC at any given dates and positions. Using this data base, several studies on the mid-latitude ionosphere were carried out. The medium-scale traveling ionospheric disturbances were detected by the GEONET TEC data and compared with the data by the other measurements, such as air-glow imagers and the MU radar. Ionospheric disturbances during the geomagnetic storm periods were studied in detail with GEONET TEC data. Less
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