Co-Investigator(Kenkyū-buntansha) |
SHIOKAWA Kazuo Nagoya University, Solar Terrestrial Environment Laboratory, Associate Professor, 太陽地球環境研究所, 助教授 (80226092)
KAWANO Hideaki Kyushu University, Faculty of Sciences, Associate Professor, 大学院・理学研究院, 助教授 (60304721)
YOSHIKAWA Akimasa Kyushu University, Faculty of Sciences, Research Associate, 大学院・理学研究院, 助手 (70284479)
OZAWA Kazuo Cosmo Design Inc., President Researcher, 取締役社長(研究職)
SETO Masahiro Tohoku Institute Technology, Professor, 通信工学科, 教授 (60085412)
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Research Abstract |
In this research, we have developed a real-time MAGnetic Data Acquisition System of Circum-pan Pacific Magnetometer Network, i.e. MAGDAS/CPMN system in Kyushu University. On the basis of the results, new fluxgate-type magnetometers and their data acquisition system from overseas sites to Japan will be constructed in the SERC, Kyushu University until the end of 2004. Magnetic field digital data(H+δH, D+δD, Z+δZ, F+δF) are obtained with the sampling rate of 1/16 seconds, and then the averaged data are transferred from the overseas stations to the SERC, Japan in real time. The long-term inclinations(I) of the sensor axes are measured by two tilt-meters with 0.2 arc-sec resolution. The temperature (T) inside the sensor bloc is also measured. The GPS signals are received to adjust the standard time inside the data logger/transfer unit. These data are logging in the Compact Flash Memory Card of 1 GB. Every day, the data logger at an overseas site generates a file containing averaged 1-see magnetic data (H,D,Z,F) and a file containing the averaged 1-minmagnetic data and inclination and temperature data (I,T) of the magnetometer sensor. The file size of the 1-sec data is less than 1.5 MB/day. The file-size of the 1-min data is less than 50KB. If the communication line at the site does not allow a fast-enough connection, the data logger sends only the 1-min file to the SERC every day ; if the connection is fast enough, the data logger sends both the 1-min file and the 1-sec file to the SERC every day. In fact, the data transfer does not have to be on a daily basis : That is, the data-transfer interval can be set to any value between 10 minutes and 1 day, depending on the condition of the following communication lines. The MAGDAS data can be transferred from the overseas stations to the SERC, Japan, by using three possible ways; special line for INTERNET, telephone line and Satellite telephone lines.
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