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| Titel |
Recalibration of the NOAA/POES MEPED instrument using a statistical approach |
| VerfasserIn |
Linn-Kristine Glesnes Ødegaard, Kjellmar Oksavik, Finn Søraas, Hilde Nesse Tyssøy |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074517
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| Zusammenfassung |
| The NOAA/POES satellites have operated with almost identical instrumentation for more
than 30 years and have collected valuable information about the particle environment in the
Earth’s magnetosphere and ionosphere. The investigation of long-term trends and
multi-satellite studies using NOAA/POES satellites involves a number of challenges. The
solid state detectors used in the MEPED instrument suffer from radiation damage by
energetic particles, which leads to an increase in the energy thresholds of the instruments. As
a consequence, particle fluxes are underestimated. In order to use the particle data in
quantitative studies the different satellites must be intercalibrated. We do a recalibration of
the MEPED instruments onboard NOAA 15-18 using a statistical approach. Right
after the launch of NOAA 19 in 2009, we chose a period of three months. During
this period daily average fluxes were calculated for NOAA 15-19. Energy spectra
based on the averaged measurements were compared for NOAA 15-18 with the
newly launched NOAA 19. By using average fluxes collected over a long time
period, we argue that satellites sampling in different regions can be compared. The
method is suitable for determining the temporal development of the degradation by
implementing the technique right after the launch of any NOAA/POES satellite.
Our approach makes use of all available proton data during the chosen calibration
period, and it estimates the change in energy thresholds of the four lowest energy
channels of the MEPED instrument. It is mandatory to perform a cross calibration
between the different POES satellites when the particle data are used for long-term
studies or calculations on the effects of particle precipitation on the atmosphere. Our
new energy thresholds are compared to results obtained by Asikainen et al. (2011
and 2012). We also investigate the difference between corrected and uncorrected
proton fluxes in regard to the ionization in the mesosphere and lower thermosphere. |
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