Digitizing UK analogue magnetogram records from large geomagnetic storms of the past two centuries.
Digitizing UK analogue magnetogram records from large geomagnetic storms of the past two centuries.
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DOI：
10.1002/gdj3.151
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发表时间：
2023-01
影响因子：
3.2
通讯作者：
Humphries, Thomas
中科院分区：
文献类型：
--
作者：
Beggan, Ciaran D.;Eaton, Eliot;Maume, Eleanor;Clarke, Ellen;Williamson, John;Humphries, Thomas
关于地球表面磁场强度和方向的连续地磁记录可以追溯到19世纪40年代。在过去的两个世纪里，英国有八个天文台，它们使用感光相纸测量每天的磁场变化，以产生模拟磁图。大约有35万张磁图被以高分辨率数码拍摄下来。然而，将迹线转换为数字值是困难且耗时的，因为磁图可能具有重叠线、低质量记录和用于转换为SI单位的模糊元数据。我们讨论了我们的方法来数字化的痕迹，从大型磁暴，并强调一些问题时要注意捕捉模拟测量的磁信息。这些措施包括将最终数字化值与天文台年鉴中记录的每小时平均值进行交叉检查，并比较同一风暴的多个天文台记录，以发现错误，例如符号倒置或纸质记录上数据的不正确“环绕”。地球表面磁场强度和方向的连续地磁记录可以追溯到19世纪40年代，其中350，000个磁图已经以高分辨率数字拍摄。将磁迹转换为数字值是困难和耗时的，因为磁图可能具有重叠线、低质量记录和用于转换为SI单位的模糊元数据。我们展示了如何数字化的痕迹，从大型磁暴和突出问题时，捕捉模拟测量的磁信息。
Continuous geomagnetic records of the strength and direction of the Earth's field at the surface extend back to the 1840s. Over the past two centuries, eight observatories have existed in the United Kingdom, which measured the daily field variations using light‐sensitive photographic paper to produce analogue magnetograms. Around 350,000 magnetograms have been digitally photographed at high resolution. However, converting the traces to digital values is difficult and time consuming as the magnetograms can have over‐lapping lines, low quality recordings and obscure metadata for conversion to SI units. We discuss our approach to digitizing the traces from large geomagnetic storms and highlight some of the issues to be aware of when capturing magnetic information from analogue measurements. These include cross‐checking the final digitized values with the recorded hourly mean values from observatory year books and comparing several observatory records for the same storm to catch errors such as sign inversions or incorrect ‘wrap‐around’ of data on the paper records. Continuous geomagnetic records of the strength and direction of the Earth's field at the surface extend back to the 1840s of which 350,000 magnetograms have been digitally photographed at high‐resolution. Converting the traces to digital values is difficult and time consuming as the magnetograms can have over‐lapping lines, low quality recordings and obscure metadata for conversion to SI units. We show how to digitise the traces from large geomagnetic storms and highlight issues when capturing magnetic information from analogue measurements.
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影响因子：
3
作者：
Clarke, Ellen;Baillie, Orsi;Turbitt, Chris W.
通讯作者：
Turbitt, Chris W.
DOI：
10.1098/rsta.2000.0569
发表时间：
2000-03-15
期刊：
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
影响因子：
--
作者：
Jackson, A;Jonkers, ART;Walker, MR
通讯作者：
Walker, MR
影响因子：
0.6
作者：
CAWOOD, J
通讯作者：
CAWOOD, J
DOI：
10.1029/2004sw000123
发表时间：
2005-08-25
影响因子：
3.7
作者：
Pulkkinen, A;Lindahl, S;Pirjola, R
通讯作者：
Pirjola, R
影响因子：
3.3
作者：
Rogers, Neil C.;Wild, James A.;Thomson, Alan W. P.
通讯作者：
Thomson, Alan W. P.