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From POLE (Particle ONERA-LANL Environment) to a
global radiation belt model
S. Bourdarie, D. Boscher, ONERA R. Friedel,
LANL R. Ecoffet, CNES
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Outline

• Introduction
• Focus on Geostationary orbit (POLE)
• Extension to all locations
• Conclusions

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Introduction
Mapping from in-situ measurements (electrons E gt
2 MeV)
(12 satellites)
(12 satellites)
From Reeves et al. EOS, 79, Decmber 15, 1998
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Focus on Geostationary orbit (POLE)
The data overview of the used satellites
LANL-97A
1994-084 1991-080
1990-095 1989-046
1987-097 1984-129
1984-037 1982-019
1981-025 1979-053
1977-007 1976-059
CPA
SOPA
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Focus on Geostationary orbit (POLE)
The data energy range of the instruments
model
ESP
SOPA
basis
CPA
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Focus on Geostationary orbit (POLE)
The raw data for the 1100-1500 keV energy channel
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Focus on Geostationary orbit (POLE)
The data Calibration of measurements comparison
with CRRES
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Focus on Geostationary orbit (POLE)
The data cross calibrated measurements for all
the original channels (reference 1984-129)
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Focus on Geostationary orbit (POLE)
Building the model analysis of the 1.1-1.5 MeV
channel
Solar max
Solar min
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Focus on Geostationary orbit (POLE)
Building the model determination of the worst
cycle and the lowest cycle
Determination of ratio
Estimation of the uncertainty of each point
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Focus on Geostationary orbit (POLE)
Estimation of the ratio between the worst/lowest
cycle and the average
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Focus on Geostationary orbit (POLE)
Result of the model and extrapolation from 37 keV
to 2.5 MeV (checked with CPA and ESP measurements)
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Focus on Geostationary orbit (POLE)
Result of the model Comparison with AE8 on a 11
year mission
Surface effects
Solar cells effects
Dose effects
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Focus on Geostationary orbit (POLE)
Validation by
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Focus on Geostationary orbit (POLE)
Validation by
8.7-14.5 MeV protons _at_GOES8
8.7-14.5 MeV protons _at_GOES8
MeV-1 cm-2 s-1 sr-1
MeV-1 cm-2 s-1 sr-1
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Extension to all locations Approach
Empirical inputs
Dynamic Salammbô code
LANL GEO series
HEO1
POLAR
GPS series
HEO3
SAMPEX
Cross calibration Validation
Interpolation Extrapolation
Time dependant space environment maps
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Extension to all locations The data base
Sept-Oct 1998
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Extension to all locations Salammbô code
including a non-dipole field
ONERA_DESP_LIBRARY
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Extension to all locations Simulation Sept-Oct
1998
Outer boundary of Salammbô L8.
POLAR
LANL-1994-084
GPS ns33
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Extension to all locations Simulation Sept-Oct
1998
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Extension to all locations Simulation Sept-Oct
1998
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Extension to all locations Simulation Sept-Oct
1998
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Conclusions

• We have first concentrated on GEO orbit (POLE)
• We used 13 satellite measurements from 1976 to
  2001 (2.5 solar cycles) to construct a model of
  electrons at GEO
• Particular attention was paid to calibration
  (cross calibration absolute calibration)
• The model was built using the year of solar
  minimum as reference (better defined)
• It gives electron flux on a one-year time
  resolution in the range 30 keV-2.5 MeV
• It gives lower values than AE8 between around 130
  keV and 2.5 MeV (factor 2 to 3) -gt solar cells
• It is publicly available
• We have potential to extend such a model to all
  locations
• Data analysis technique
• Data assimilation with Salammbô