Development of Data Acquisition System for Space Weather Study

在本研究中，我们在九州大学开发了一套环太平洋磁强计网络实时磁数据采集系统，即MAGDAS/CPMN系统。在此基础上，九州大学SERC将在2004年底之前建造新的磁通门式磁强计及其从海外到日本的数据采集系统。以1/16秒的采样率获得磁场数字数据(H+δH、D+δD、Z+δZ、F+δF)，然后将平均数据从海外台站实时传送到日本SERC。传感器轴线的长期倾角(I)是用两个0.2角秒分辨率的倾斜仪测量的。还测量了传感器块内的温度(T)。接收GPS信号以调整数据记录器/传输单元内的标准时间。这些数据记录在1 GB的紧凑型闪存卡中。每天，海外站点的数据记录仪都会生成一个包含平均1-SEE磁数据(H、D、Z、F)的文件和一个包含平均1分钟磁数据以及磁强计传感器的倾角和温度数据(I、T)的文件。1秒数据的文件大小小于1.5 MB/天。1分钟数据的文件大小小于50KB。如果现场的通信线路不允许足够快的连接，数据记录器每天只向SERC发送1分钟文件；如果连接足够快，数据记录器每天向SERC发送1分钟文件和1秒文件。事实上，数据传输不必每天进行：也就是说，数据传输间隔可以设置为10分钟到1天之间的任意值，具体取决于以下通信线路的状况。MAGDAS数据可以通过三种可能的方式从海外站传输到日本SERC：互联网专线、电话线和卫星电话线。

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.