Future Solar UV Observations: LYRA and SWAP on PROBA2

1. LYRA and SWAP on board PROBA2Heralding future solar UV observations J.-F. Hochedez & D. Berghmans (SIDC-ROB) J.-M. Defise (CSL-ULg) + the LYRA and SWAP teams

2. Where to go, with solar UV observations? (Long-term) temporal coverage Temperature range/coverage (spectral resolution) High Cadence Spatial resolution Field of View Unexplored region of interest

3. This is not a pipe - 1929 This .. is not the Sun This is not the Sun either René Magritte

4. 1 – Spatial resolution AIA/SDO Temporal coverage Temperature range (spectral resolution) AIA/SDO Cadence AIA/SDO Spatial resolution Field of View Trace Vault AIA/SDO Solar orbiter SDO launch 2008

5. The quest for finer Spatial resolution SOHO-EIT3600 km at Sun TRACE 1 Arcsec resolution ~ 700 km at Sun VAULT 0.33 Arcsec resolution ~ 240km @ Sun Solar Orbiter ~100 km @ Sun

6. Brightenings time constants, extrapolation Mm2 1000 Berghmans A&A 98 EIT & TRACE Max Cadence 100 60ms .6s 6s 1’ 10’ 100’ min 10 ~ 100 ms 10Hz EIT-SOHO pxl 1 TRACE pxl .1 .01 Factor 100 Solar Orbiter imager pxl .001

7. The curse of high resolution The higher effective area , the better Signal-to-Noise ratio to be maintained or increased. Radiance of Solar features (filling factor will help?) Distance to Sun. Exposure Time (controls cadence) Area @ Sun

8. 2 – Cadence and extended temporal coverage SDO SWAP & LYRA Temporal coverage SDO SWAP & LYRA Temperature range (spectral resolution) Cadence SDO Spatial resolution Field of View Trace Vault SDO Solar orbiter SDO

9. Quest for « adequately high » cadence • PROBA2 • Launch end 2007 (2-year mission) • 60 cm x 70 cm x 85 cm, 120 kg • LEO dawn-dusk orbit • Demonstrate new space technologies SWAP & LYRA « the High-cadence solar mission » Image courtesy: Verhaert

10. Sun side view DSLP DTU Star Tracker Bepi Colombo Star Tracker Solar Panel Concentrator DSLP Digital Sun Sensor LYRA SWAP Thermal Plasma Measurement Unit Sun

11. Anti-sun view (open) S Band Reaction Wheels Resistojet

12. 2 solar instruments • LYRA • UV radiometer • PI: JF Hochedez • LYRA.oma.be • SWAP • EUV imager • PIs: D Berghmans JM Defise • SWAP.oma.be Sun

14. LYRA Melody instrument of Apollo, Greek god of the Light and the Sun An XUV - VUV solar Radiometer using solarblind diamond UV detectors

15. LYRA Flight Model (PFM) in the synchrotron calibration facility in PTB, Berlin

16. LYRA instrument consortium :a Belgian-Swiss team with international partners

17. LYRA highlights • 4 channels covering a wide temperature range • 200-220 nm Herzberg continuum range (interference filter) • Lyman-alpha (121.6 nm, interference filter) • Aluminium filter channel (17-70 nm) incl. He II at 30.4 nm • Zirconium filter XUV channel (1-20 nm) • rejects strongly He II • Traceable to radiometric standards • Calibration campaigns at PTB Bessy synchrotron • In-flight stability • Rad-hard, not-cooled, oxide-less diamond UV sensors • 2 different LEDs per detector • Redundancy (3 units) • High cadence (up to 100Hz) • Quasi-continuous acquisition during mission lifetime

18. Inside LYRA 315.0 x 92.5 x 222.0 mm ~A4 size 2.85W (<5W required) 3.533 kg 3 units 12 detectors 24 LEDs … 1 unit = 4 wavelength channels

19. One of the 3 LYRA units

20. Dec 2005 tbc April 2006 tbc

21. LYRA Detectors • PiN and photoconductor (PC) diamond UV sensors • Solar blindness (5.45 eV, less filters, more signal) • Radiation hardness • Low thermal noise (No need for cooling) • Chemical inertness • Mechanical stability • Highest thermal conductivity • IRD/AXUV-20 Si diodes • Good heritage Merit of diamond UV sensor

22. PIN and MSM

23. Solar blind diamond detectors Ø 5mm Ti/Pt/Au contacts– diamond MSM structures 5V diamond PiN sensor IMOMEC, Belgium with the collaboration of the National Institute for Materials Science (NIMS), Japan. MSM structures and PiN junctions, depending on the LYRA channel.

24. Calibrations & radiometric model Tests and calibrations made at PTB/BESSY, Berlin, Germany

25. SWAP onboard PROBA2 A new EUV imager for solar monitoring Sun Watcher Using APS and Image Processing Sun

26. SWAP, off-axis EUV imager Focal plain assembly radiator Secondary mirror Primary mirror Door(closed) baffle Image courtesy AMOS S.A.

27. Proba2-SWAP (1/2)

28. Proba2-SWAP (2/2) • New technologies: • APS CMOS detector • Off-axis optical design • Onboard image processing

29. J. M. Defise J.H. Lecat T. Thibert L. Rossi P. Rochus P. Franco J.M. Gillis E. Mazy J.P. Halain MF Ravet R Mercier P. Nicolosi D. Berghmans J.F. Hochedez B. Nicula G. Lawrence A. Zhukov V. Slemzin R. Van der Linden F. Clette L. Wauters T. Katsyannis L. Podladchikova U. Schuehle

30. SWAP TARGETS Dimmings EIT wave Post-eruption arcade Loop openings plasmoid lifting flares Erupting prominences

31. ‘EIT CME watch’- like data: 1k2 images of the corona 17.5 nm instead of 19.5 nm 54’ FOV instead of 45’ 1 min instead of 15 min SWAP

32. PROBA-2 allows off-pointings 3 Rsun

33. Missions Timeline & Swap complementarities I : UV imaging C: Coronagraph R: UV Radiometer Mission complementarities (1/2) S: stereo ability

34. Image recognition • ON-BOARD:SWAP produces 10x more data than what its TM budget can support: • near loss-less image compression • image selection • ON THE GROUND: automated detection of space weather events: • flares, EIT waves, prominence/filament eruptions

35. SWAP highlights • SWAP will image and report all the solar drivers of space weather (coronal holes, flares, CME signatures) • SWAP will observe the EUV full disk at a 1 min cadence • SWAP+LYRA provide the EUV equivalent in Europe of the NOAA SXI + GOES X-ray monitor • SWAP demonstrates new technologies for small EUV imagers: CMOS, off-axis, shutterless, image recognition…

36. SWAP & LYRA in space • A first for Belgian astronomy • Thrilling technology at the service of pioneering solar physics. • PROBA2 heralds future solar UV observations • Swap & Lyra science consortia are turning European and international

37. Solar-blind UV imagers for solar missions • BOLD Blind to the optical light detectors • Started: June ‘06 • 2 year project

38. Solar image processing • Currently possible to detect • Flares, including small ones • Dimmings • CMEs • Optimize for onboard reliable operations • Onboard autonomy (mode settings) • Data filtering/selection • Adaptive compression (3x  15x  200x)

39. Flare automatic detection • Discrepancy from power law behaviour of wavelet spectrum: X-flare M-flare C- or B-flare Quadratic fit

40. Example of flaring activity detected by the algorithm Post flaring activity on May 1, 18:36 End of B-flare Recorded on May 5, 00:20

41. Physics of the Sun Atmosphere today (1/2) • Coronal heating • Magnetic field, morphology, solar structure(s), activity • Large-scale transients • Emission mechanisms, irradiance, and abundances • Solar cycle studies, atmospheric signatures of the dynamo • Heliospheric studies, solar wind, Space Weather

42. Physics of the Sun Atmosphere today (2/2)Some research (or operational) fields & keywords • Coronal heating : • Energy transport from convection zone to upper atmosphere, loop models, MHD & kinetic modeling, physics of the TR, moss, variability… Nanoflare / DC –based heating, MHD wave / AC –based heating, AR vs QS heating • Magnetic field, morphology, solar structure(s), activity : • Topology, handling complexity (eg. SOC), coupling of scales, MHD modelling, magnetogram MHD extrapolations, physics of reconnection, of MHD waves, coronal seismology, variability (why), helicity… • Phenomenology, all atmospheric structures: CH, prominences, plumes, BP, blinkers, explosive events, and all small-scale transients, (macro-) spicules, chromospheric network, mag. carpet, interconnecting and transequatorial loops, canopy, ARCH … • Large-scale transients : • CMEs, Flares, Eruptive prominences, Moreton & EIT waves - Their formation, trigger(s), timing, precursors, numerous scenarii, non-equilibria, helicity… • Validity of operational SpW nowcasting and forecasting • Emission mechanisms, irradiance, and abundances : • Ly-alpha (H&He), FIP effect, atomic processes, ionization balance, DEM analysis, radiative transfer/loss, plasma properties, diagnostics, irradiance budgets, impact on Earth thermosphere and ionosphere, variability (how)… • Solar cycle studies, atmospheric signatures of the dynamo : • SOHO follow-up in cycle 24, All long-term studies, differential rotation of tracers, 1.3-year periodicity in the Corona, new proxies, helicity (shedding), active longitudes… • Heliospheric studies, solar wind, Space Weather : • Fast & slow wind acceleration, large-scale transients, AR expansion, CH, streamers, H & He distribution, Doppler dimming, inflows, blobs, plasmoids, geoeffectiveness, SpW Forecast, Climate Global Change… Not thorough, but already impracticable…

43. Large cross-talk between goals and techniquesillustrative examples Results/discoveries need combination of several techniques

44. Engineering budgets • Volume • 60x70x80 cm Mass budget • Total mass: 120 Kg • Platform mass: 85 Kg • Payload mass: 35 Kg Power budget • Power: 130 W (solar arrays), 88 W peak consumption • Battery: 16.5 Ah Processing budget • Processor: SPARC V8 at 100 MHz (LEON), 100 MIPS, 2 MFLOPS • Memory: 512 Mbit (processor), 3 Gbit (data) Pointing budget • Stability: 5 arcsec over 10 s • Absolute: 100 arcsec Link budget • 16 Kbit/s uplink (omni-directional) • 1 Mb/s downlink

45. Enlarged field of view 2.36 R FOV: 45 arcmin FOV: 54 arcmin 1.67 R