Geomagnetic Observatory St. Helena, preliminary hourly mean values 2010, XYZ components

The data set contains preliminary hourly mean values of the geomagnetic observatory St. Helena for 2010. The hourly means are calculated from minute means, which are based on 2 Hz raw data from an observatory grade, three component fluxgate magnetometer of type DTU FGE. The raw data is calibrated by means of weekly absolute measurements of the geomagnetic field at the observatory main pillar. The data set is provisional. Specifically, the data is visually controlled, but the applied baselines and formulas for calibration are not yet adopted in their final form. We expect the present preliminary data to be within a few nT of the final data that will eventually be distributed through the World Data Centres and INTERMAGNET.The data file is in ASCII format and contains blank separated first the month, day and hour of the time stamp of the data in the format MM DD HH followed by the hourly mean value of the geomagnetic field components X (North), Y (East) and Z (down) in nanotesla (nT). The time stamp is given for the beginning of the hour, for which the mean value of the field component is given.Geomagnetic observatories are described in e.g. Jankowski and Sucksdorf (1996). The St. Helena geomagnetic observatory was established by GFZ in 2007 and is operated by GFZ since. The network of geomagnetic observatories operated by GFZ and the observatories' instrumentation are described in Matzka (2016, http://doi.org/10.17815/jlsrf-2-136). Jankowski, J., and C. Sucksdorff, 1996, Guide for Magnetic Measurements and Observatory Practice, International Association of Geomagnetism and Aeronomy, Warsaw, 235 pp. ISBN 0-9650686-2-5, http://www.iaga-aiga.org/data/uploads/pdf/guides/iaga-guide-observatories.pdf

本数据集包含圣赫勒拿地磁观测站（St. Helena geomagnetic observatory）2010年的逐小时平均值初步数据。该逐小时平均值由分钟平均值计算得到，而分钟平均值则基于观测台站级DTU FGE型三分量磁通门磁力仪（three component fluxgate magnetometer）采集的2 Hz原始数据。原始数据通过每周对观测站主标杆处的地磁场开展绝对测量完成校准。本数据集为暂定版本：数据已完成目视核验，但所用的校准基线与校准公式尚未采用最终形式。我们预计当前的暂定数据与最终将通过世界数据中心（World Data Centres）和国际地磁台站网（INTERMAGNET）发布的最终数据之间的偏差仅为数纳特斯拉（nanotesla, nT）。数据文件采用ASCII格式，以空格分隔，首列依次为数据时间戳的月（MM）、日（DD）、时（HH），随后为地磁分量X（北向）、Y（东向）与Z（向下）的逐小时平均值，单位为纳特斯拉（nT）。该时间戳对应小时的起始时刻，此时段内的磁场分量平均值即为该条目的数值。地磁观测站的相关规范可参见Jankowski与Sucksdorf（1996）。圣赫勒拿地磁观测站由GFZ于2007年建立，此后由该中心负责运维。GFZ运营的地磁观测台站网络及各台站的仪器配置可参见Matzka（2016，https://doi.org/10.17815/jlsrf-2-136）。参考文献：Jankowski, J. 与C. Sucksdorff, 1996，《地磁测量与观测台站操作指南》，国际地磁与高空物理学协会（International Association of Geomagnetism and Aeronomy），华沙，235页。ISBN 0-9650686-2-5，https://www.iaga-aiga.org/data/uploads/pdf/guides/iaga-guide-observatories.pdf