1. European Space Weather Week - 13
Space weather products based on Energetic Particle Telescope (EPT) data measured on-board PROBA-V by
S. Borisov, S. Benck and M. Cyamukungu
(UCL/ELI/CSR)
14-18 November 2016
Oostende, Belgium

2. EPT instrument and mission
Overview of the products
Conclusions
The EPT concept
Detecting electrons, protons and He without inter-species contamination Δx
Stack E2 E1
Two particles belonging to different species (1 and 2), having the same «range» can be readily identified if their stopping power (S1, S2) in Δx are different.
Achieve ~error-free particle discrimination through «coincident identification» where the result from the «Δxa-Stack assembly» is cross-validated by that from the «Δxb-Stack assembly».
Δxa
Δxb E2 E1

3. EPT instrument and mission
Overview of the products
Conclusions
Proba-V with EPT onboard was launched on 7 May 2013 into a sun-synchronous polar orbit at 820 km altitude (inclination 98.7°, Local Time at Descending Node 10:45)
The EPT is oriented WEST when in daylight and oriented EAST when in eclipse
The formal EPT commissioning has started on 21 June and completed on 3 September 2013.
Volume: x 16.2 x cm3
Mass: 4.6 kg
Power consumption: < 6 W

4. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Product available today for electrons, protons and helium:
Flux time-series along the orbit at 2 s step (mainly).
Flux time-series in fine B-L bins.
Static radiation model for covered region of magnetosphere.
Up to 4 day ahead radiation environment prediction.
Weekly average flux maps on regular geographical grid with 4° step.
Characteristic energy spectra for the Polar region L>3 (electrons) and SAA, 1.1<L<2.1 and 0.16<B(G)<0.22 (protons and helium).

5. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Flux time-series along the orbit at 2 s step (mainly)

6. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Flux time-series in fine B-L bins
47 bins for B [0.15 – 0.5] G;
160 bins for L [1.0 – 30.] +1 for positions without L.
~4050 B-L bins visited.
1 B-L bin = 1 file for one year.
The same time series format as in along-orbit measurements file.

7. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Static radiation model for covered region of magnetosphere
Time period 24/06/ /06/2014
Selection on boresight orientation (90°± 25°)

8. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Electrons - Outer Radiation Belt
Convenient for cross-validation purposes

9. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Up to 4 day ahead radiation environment prediction
Flux forecast based on lifetime measurements (by S. Benck et al, 2010) for every B-L bin for every channel of every particle:
Forecasting decaying flux.
Updated after every new run processed.

10. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Electron lifetime calculation
Possible 3-week flux forecast possible based on lifetimes and real-time flux measurements.
The relationship between Dst and the flux variation remains to be understood.
See also Benck et al. , Low altitude energetic electron lifetimes after enhanced magnetic activity as deduced from SAC-C and DEMETER data, Ann. Geophys., 28, 849–859, 2010
L= , B= G, E= MeV, T = 4.9±1.1 days

11. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Electrons - Outer Radiation Belt
Mis-forecasting probability is equivalent to geomagnetic storm occurrence probability.

12. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Weekly average flux maps on regular geographical grid with 4° step

13. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Characteristic energy spectra for the Polar region L>3 (electrons) and SAA, 1.1<L<2.1 and 0.16<B(G)<0.22 (protons and helium)

14. EPT instrument and mission
Overview of the products
Conclusions
Conclusions
PROBA-V/EPT project provides a number of high quality particle data products available to the space research community.
The UCL/CSR team is open for collaboration with space radiation research community for further exploitation of the EPT data.

15. Thank you! Acknowledgments
EPT instrument and mission
Overview of the products
Conclusions
Acknowledgments
BELSPO for funding of PROBA-V/EPT DE project
ESA Redu station for PROBA-V operations
BUSOC for initial PROBA-V/EPT data handling
Thank you!

16. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Spare info.
Active PROBA-V/EPT data users:
ESA
BIRA (Belgium)
DH Consultancy (Belgium)
NOA (Greece)
BAS (UK)
University of Calgary (Canada)
SINP (Russia)
University of Arkansas at Pine Bluff (USA)
SES - Luxembourg

17. EPT instrument and mission
Overview of the products
Conclusions
The EPT
Volume: x 16.2 x cm3
Mass: 4.6 kg
Power consumption: < 6 W
Particle
Channel limits (MeV)
Electron
Proton
Helium
Modular and reconfigurable
Extended version (6 DAMs instead of 10): bigger energy range and smaller size and mass: protons up to 1 GV in 11 channels with (approx.) 17x14x11 cm3-3.5kg-5W

18. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Model generation
Path average the data in all the position bins
For each (B,L) bin draw the cumulative distribution function CDF for the fluxes in each energy bin
Fit the data with a Weibull function to determine the lower part of the CDF function delimited by the flux sensitivity limit of the detector (the selected dataset must at least have 10 data points)
Draw the normalized PDF for the flux based on the data as well as the fit result
CDF
PDF

19. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions ?
Flux Sensitivity limit
= 110 (s-1•sr-1•MeV-1•cm-2)

20. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Electrons - Outer Radiation Belt

21. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Electrons - Outer Radiation Belt

22. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Protons - Inner Radiation Belt

23. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Protons - Inner Radiation Belt
!!! East – West asymmetry not taken into account

24. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Study of relevant parameters for flux forecasting.
Example:
Flux enhancement (deltaF in cm-2 s-1 sr-1) distribution functions as deduced from the SAC-C data.
Probability of mis-forecasting
Waiting time distribution (Time between the occurrence of two events characterized by a Dst <-50nT).
The continuous lined histograms: quiet solar activity periods and the dashed lined histograms: high solar activity periods. The blue continuous and dashed lines represent a fit of the probability functions with a poissonian distribution: P( Tw ) = r exp( - r TW ) with r=1/ 𝑻 𝑾 .

25. Overview of the products
EPT instrument and mission
Overview of the products
Conclusions
Helium and protons during SPE-2014/01
38-51 MeV
MeV
MeV
MeV