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| Titel |
Automatic parameterization for magnetometer zero offset determination |
| VerfasserIn |
M. A. Pudney, C. M. Carr, S. J. Schwartz, S. I. Howarth |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2193-0856
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Instrumentation, Methods and Data Systems ; 1, no. 2 ; Nr. 1, no. 2 (2012-08-30), S.103-109 |
| Datensatznummer |
250000164
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| Publikation (Nr.) |
 copernicus.org/gi-1-103-2012.pdf |
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| Zusammenfassung |
| In-situ magnetic field measurements are of critical importance in
understanding how the Sun creates and controls the heliosphere. To ensure the
measurements are accurate, it is necessary to track the combined
slowly varying spacecraft magnetic field and magnetometer zero offset – the
systematic error in the sensor measurements. For a 3-axis stabilised
spacecraft, in-flight correction of zero offsets primarily relies on the use
of Alfvénic rotations in the magnetic field. We present a method to
automatically determine a key parameter related to the ambient compressional
variance of the signal (which determines the selection criteria for
identifying clear Alfvénic rotations). We apply our method to different
solar wind conditions, performing a statistical analysis of the data periods
required to achieve a 70% chance of calculating an offset using Helios
datasets. We find that 70% of 40 min data periods in regions of fast
solar wind possess sufficient rotational content to calculate an offset. To
achieve the same 70% calculation probability in regions of slow solar wind
requires data periods of 2 h duration. We also find that 40 min data
periods at perihelion compared to 1 h and 40 min data periods at aphelion
are required to achieve the same 70% calculation probability. We compare
our method with previous work that uses a fixed parameter approach and
demonstrate an improvement in the calculation probability of up to 10% at
aphelion and 5% at perihelion. |
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