1. VALIRENE WP5000 Toolkit and Validation
Commercial-in-Confidence – not for public release
VALIRENE WP5000 Toolkit and Validation
Pete Truscott & Daniel Heynderickx
Kallisto Consultancy & DH Consultancy
ESTEC, 12th November 2018
12/11/2018

2. Purpose-Built Toolkit for Validation
Comprehensive toolkit to generate spacecraft trajectories, calculate trapped environment fluxes and fluences, and shielded effects
Python-based (v3.6), strongly OO’d toolkit
Interfaces with:
PyIRENE (CythonIRENE C++ subroutines/classes, v ) and can also read in IRENE-generated O/P files
Access to established models: AP8, AE8, CRRES-PRO, CRRES-ELE
IGE, MEOv1 and MEOv2 models implemented in Python
SRREM API from DHC – not yet fully linked-in
NAIF SPICE orbit generator
Can input and process some SPENVIS files types (e.g. SAO, SPE, SPP, etc)
Comparison and manipulation of:
flux- and fluence-based quantities
TID, TNID, DDEF
Python API for ODI database interface
Operates in Linux, but intended for Windows as well
12/11/2018

3. Validation performed against instrument datasets
Data processed - protons:
Integral/IREM, 60s ( , , 2016 – 2018)
RBSP-A/RPS, 60s, ( )
RBSP-A/REPT, 120s ( )
PROBA-1/SREM, 60s ( )
Azur/EI-88, 60s (1969 & 1970)
XMM/ERMD, 60s (2000 – 2017)
Data processed – electrons:
Integral/IREM, 60s ( )
RBSP-A/REPT, 120s ( )
PROBA-1/SREM, 30s ( )
CRRES/MEA, 60s ( )
XMM/ERMD, 60s (2000 – 2018)
Data processed – counts
IREM and SREM
12/11/2018

4. IRENE Model Outputs Additional quantities used:
Description
Mean
Conventional mean of the environment at each point
Percentile
Captures statistical behaviour of the data upon which the model is built
Perturbed Mean
Includes uncertainties in mean flux maps due to measurement and gap-filling errors
Monte Carlo
Includes “perturbed” mode uncertainties, and adds estimate of dynamic variations due to space weather
Additional quantities used:
Perturbed Mean Percentile (PMP) – based on 40 different Perturbed Mean calculations for the same trajectory, and determination of the 95th or 75th percentile of the environment overall or for LL+L
Monte Carlo Percentile (MCP) – based on 40 different Monte Carlo calculations for the same trajectory, and determination of the 95th or 75th percentile of the environment overall or for LL+L
12/11/2018

5. INTEGRAL/IREM Proton comparisons
12/11/2018

6. INTEGRAL/IREM Proton comparisons (12.4 – 41.1 MeV)
12/11/2018

7. INTEGRAL/IREM Proton comparisons (52.2 – 173.0 MeV)
12/11/2018

8. RBSP-A/REPT and RBSP-A/RPS Proton comparisons
12/11/2018

9. RBSP-A/RPS Proton comparisons (58.1 – 143.0 MeV)
12/11/2018

10. Proton Energy Spectra
12/11/2018

11. Summary for Level of Agreement for AP9 versus AP8
12/11/2018

12. INTEGRAL/IREM Electron comparisons
12/11/2018

13. INTEGRAL/IREM Electron comparisons (0.7 – 1.8 MeV)
12/11/2018

14. CRRES/MEA Electron comparisons (0.14 – 0.51 MeV)
12/11/2018

15. CRRES/MEA Electron comparisons (0.6 –1.09 MeV)
12/11/2018

16. Electron Energy Spectra
12/11/2018

17. Electron Mean Annual Flux* *
* IRENE 95th MC percentile * *
12/11/2018

18. Summary for Level of Agreement for AE9 versus AE8
12/11/2018

19. Model results for standard orbits
Four standard orbits considered:
GEO 75E, but also some results for 180E and 285
MEO: 20,500km, 55 (GPS orbit)
SSO: 800km, 98.6
ISS: 450km , 51.6
Electric propulsion orbit raising trajectories (courtesy of OHB):
GTO to GEO, <0.25 142 days
LEO to MEO, 56, 349 days
LEO to GEO, 1, 387 days
12/11/2018

20. Electron Spectra for GEO and MEO
IRENE Mean and PMP within a factor of 1.7 over 0.4 – 10 MeV
AE8MAX predicts slightly higher fluxes than IRENE 95th PMP
Difference between MEOv2 upper and mean fluxes greater than differences in the IRENE and AE8MAX results
Very good agreement between AE9 and AE8 0.1 to 4 MeV
>0.1 MeV, IRENE can be >10 higher than IGE
The flux predicted by AE9 at 10MeV may be an artifact of the model
12/11/2018

21. Proton Spectra for SSO and ISS
AP9 does not predict softer component <1MeV
From 1 to 100 MeV, AP9 results 2.2 AP8MIN or 2.8 AP8MAX
Again AP9 does not predict softer component <1MeV
AP8MIN between 1-50 MeV matches the AP9 mean, but AP8MAX is up to 11 lower
IRENE 95th PMP results 2- 3 the IRENE Mean predictions
12/11/2018

22. Conclusions (1) Protons:
The IRENE provides Mean model is in better agreement with data than AP-8 for >40-50 MeV and for L above > (depending on energy)
Within 15 – 40MeV, AP8 appears to be better, as well as for higher energies at L below 
Note: improved model for low-altitude region being developed for ESA RENELLA Project activity.
Electrons
For L-regions >2.5 comparisons indicate that the IRENE Mean model for electrons provides comparable performance as AE-8 models
There are regions (defined in terms of energy and L-range) where IRENE is better (particularly at energies >2 MeV) but:
not systematically definable
often there are significant differences between the model and data
12/11/2018

23. Conclusions (2)
For low-altitude, high-inclination orbits, IRENE should be used with caution
Neither the Perturbed Mean nor Monte Carlo modes (PMP and MCP results) seem to be able to capture the dynamic range seen in the electron data
AE9 IRENE 95th PMP combined with 2x AE-8 MAX may provide a design margin based on the mean flux from the data
Further assessment of this approach needed, considering variability/uncertainties in measured environment
12/11/2018

24. Conclusions (3)
IGE-2006 predicts much lower GEO electron fluxes than IRENE and AE-8 predictions
Note IRENE may overestimate the high energy electron fluxes
IRENE Mean and 95th PMP environment and effects are typically between the equivalent values predicted by MEOv2
For EPOR trajectories:
For short (<1 year) trajectories, IRENE Monte Carlo-model mode should also be used to aggregate the fluence and effects quantities
Dominance of the trapped protons on the effects means space weather variability modelled by IRENE is of second-order importance for the GTO-to-GEO trajectory
Validation will be further refined and extended during the remainder of the VALIRENE project
12/11/2018