リファレンスを利用したULF磁場データの大局的変動の推定と観測点固有変動の検知

カテゴリ: 論文誌(論文単位)

グループ名: 【A】基礎・材料・共通部門

発行日: 2011/09/01

タイトル(英語): Global Variation of ULF Geomagnetic Fields and Detection of Anomalous Changes at a Certain Observatory using Reference Data

著者名: 服部　克巳（千葉大学大学院理学研究科），韓　鵬（千葉大学大学院理学研究科），黄　清華（北京大学地球与空間科学学院）

著者名(英語): Katsumi Hattori (Graduate School of Science, Chiba University), Peng Han (Graduate School of Science, Chiba University), Qinghua Huang (School of Earth and Space Sciences, Peking University)

キーワード: ULF磁場データ，大局的変動，日変化，地磁気脈動，ウェーブレットフィルタ，主成分解析　　ULF geomagnetic data，global variation，daily variation，geomagnetic pulsation，wavelet filter，principal component analysis

要約(英語): By using multiple reference stations, we have developed a method to get reliable ULF global geomagnetic variations. This background is extremely useful for detecting local anomalous behaviors. This paper demonstrates developed variable tools to identify the anomalies in two frequency ranges; daily variation and 10-1000 seconds. For estimating background daily variations, the periodical model has been applied for data observed at 3 reference stations and a study station. Comparison between the first principal component of the periodical data from the reference stations and the periodical data derived from the target station provides high correlation in general. For data with 100 sec periods after wavelet filtering, the nighttime energy variations have been investigated among 3 reference stations and a study station. The similar principal component analysis as the diurnal variation has been performed and results also show high correlation between the variation at the target and the global background. These tendency suggest that the developed two methods are effective to identify the anomalies in automatic. Examining the original data, we can know details of waveform and distinguish whether the anomalies is related to underground activities or just some artificial noises.

本誌: 電気学会論文誌A（基礎・材料・共通部門誌） Vol.131 No.9 （2011） 特集：自然災害軽減のための電磁界技術

本誌掲載ページ: 698-704 p

原稿種別: 論文／日本語

電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejfms/131/9/131_9_698/_article/-char/ja/