| Project/Area Number |
09650480
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
計測・制御工学
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| Research Institution | TOYAMA PREFECTURAL UNIVERSITY |
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Principal Investigator |
OKADA Toshimi TOYAMA PREFECTURAL UNIVERSITY,FACULTY OF ENGINEERING,PROFESSOR, 工学部, 教授 (90008566)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1998: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1997: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | SMALL-SIZE ANTENNA / PLASMA WAVE / SPACECRAFT / ELECTROMAGNETIC INTERFERENCE / DIGITAL SIGNAL PROCESSOR / インテリジェントフロントエンド / ディジタルシグナルプロセッサ / 自然プラズマ波動 |
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| Research Abstract |
We have developed a small-size dipole antenna system which to be installed onboard spacecraft to measure the plasma waves in the planetary magnetosphere and inter-planetary space. Main difficulty in designing such antenna system is how to reduce the interference electromagnetic noises from the electrical equipment onboard spacecraft, and we have developed a signal processor for real-time noise rejection using the digital signal processor (DSP), in which we used the "median filtering method". We have examined various electromagnetic noise from GEOTAIL, AKEBONO and NOZOMI satellites and obtained some common features among them, and characteristic differences from the natural plasma waves. Using such a characteristic difference we have implemented software on the DSP to suppress considerably the periodic instrumental noises. In this new filtering technique, there is no deformation in the waveform of the plasma wave. The small-size antenna can be installed along the satellite spin axis, which will make us to measure simultaneously three dimensional wave vectors of plasma waves.
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