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Solar Irradiance Observations with LYRA on PROBA2 (An Introduction) I. E. Dammasch , M. Dominique & the LYRA Team. Royal Observatory of Belgium. LYRA: the L arge- Y ield RA diometer. 3 instrument units (redundancy) 4 spectral channels per head 3 types of detectors,
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Solar Irradiance Observations with LYRA on PROBA2 (An Introduction) I. E. Dammasch, M. Dominique & the LYRA Team Royal Observatory of Belgium
LYRA: the Large-Yield RAdiometer • 3 instrument units (redundancy) • 4 spectral channels per head • 3 types of detectors, Silicon + 2 types of diamond detectors (MSM, PIN): - radiation resistant - insensitive to visible light compared to Si detectors • High cadence up to 100 Hz
LYRA highlights • Royal Observatory of Belgium (Brussels, B) • Principal Investigator, overall design, onboard software specification, science operations • PMOD/WRC (Davos, CH) • Lead Co-Investigator, overall design and manufacturing • Centre Spatial de Liège (B) • Lead institute, project management, filters • IMOMEC (Hasselt, B) • Diamond detectors • Max-Planck-Institut für Sonnensystemforschung (Lindau, D) • calibration • science Co-Is: BISA (Brussels, B), LPC2E (Orléans, F)…
LYRA highlights • 4 spectral channels covering a wide emission temperature range • Redundancy (3 units) gathering three types of detectors • Rad-hard, solar-blind diamond UV sensors (PIN and MSM) • AXUV Si photodiodes • 2 calibration LEDs per detector (λ = 465 nm and 390 nm) • High cadence (up to 100Hz) • Quasi-continuous acquisition during mission lifetime
SWAP and LYRA spectral intervals for solar flares, space weather, and aeronomy LYRA channel 1: the H I 121.6 nm Lyman-alpha line (120-123 nm) LYRA channel 2: the 200-220 nm Herzberg continuum range (now 190-222 nm) LYRA channel 3: the 17-80 nm Aluminium filter range incl the He II 30.4 nm line (+ <5nm X-ray) LYRA channel 4: the 6-20 nm Zirconium filter range with highest solar variablility (+ <2nm X-ray) SWAP: the range around 17.4 nm including coronal lines like Fe IX and Fe X
LYRA pre-flight spectral responsivity (filter + detector, twelve combinations)
LYRA data products and manuals… …available at the PROBA2 Science Center: http://proba2.sidc.be/
Summary: FITS File Structure • lyra_20100609_000000_lev1_***.fits • where: *** = met, std, cal, rej, (bst, bca, bre) • generally: header + binary extension table(s) • extension = header + data (variable length) • Lev1 met = HK, STATUS, VFC • Lev1 std = uncalibr. irradiance (counts/ms) • Lev2 std = calibr. irradiance (W/m²) • Lev3 std = calibr. aver. irradiance (W/m²) • per line: time, ch1, ch2, ch3, ch4, qual.
Product Definition • (“Level 0”, telemetry from PROBA2, internal) • Level 1 = full raw data (LY-EDG output) • Level 2 = calibrated physical data (LY-BSDG output) Caution: preliminary status. Require versioning. • Level 3 = processed products (e.g. averages) • Level 4 = plots of products • Level 5 = event lists (optionally with plots)
Further Data Products… …“Level 4”, “Level 5” (from preliminary to current status):
interval around a flare (-1h,+2h)
State of the data processing pipeline fits fits fits Current state In the future Telemetry packets Not distributed Not distributed LY-TMR: “Lev0”: Raw data (in counts) LY-EDG After each contact After each contact Lev1: Engineering data (in counts/ms) LY-BSDG fits After each contact After each contact Lev2,Lev3: Calibrated data (in W/m²) Plots regular, Flare list irregular systematic Other tools Higher level data products
Spacecraft maneuvers SAA Aurora Oval • Perturbations appearing around 75° latitude • 2-3 days after a CME, flare ... • Associated to geomagnetic perturbations
Aeronomy • Occultations: Study atmospheric absorption; high temporal resolution needed • Input for atmospheric models: NRT and calibrated data needed
Flares • LYRA observes flares down to B1.0 • LYRA flare list agrees with GOES14&15 • Flares are visible in the two short-wavelength channels • Exceptionally strong and impulsive flares are also visible in the Lyman- alpha channel (precursor) • Example: C4.0 flare, 06 Feb 2010, 07:04 UTC
Comparison with GOES flare Example: M1.8 flare, 20 Jan 2010, 10:59 UTC
ComparisonwithGOES flare Example: C5.4 flare, 15 Aug 2010, 18:30 UTC
LYRA flare size LYRA background-subtracted flux in Zr (channel 2-4) • LYRA observes all GOES flares in both Al and Zr channels • Initially also Lyman-alpha contribution for strong impulsive flares • Similar onset, different peak times in different pass bands • Good correlation to GOES, better temporal resolution
GOES vs. LYRA proxies (new website under construction)
Example:M1.1 flare, 28 Feb 2011 • start to rise at same time • parallel in impulsive phase • GOES peaks earlier • LYRA decreases slower • linear factor in pure flare • irradiance
Flare components ch2-3 = SXR+EUV • “SXR”: emission with log(T)>7 • “EUV residual”: emission with 6<log(T)<7 • “little bump”: emission with log(T)<6 • Compare with SDO/EVE:
Thermal evolution plot • based on: • solar spectra observed by SDO/EVE • contribution functions from the CHIANTI atomic database
Sun-Moon eclipse …demonstrating the inhomogeneous distribution of EUV radiation across the solar surface
Eclipses as seen with SWAP swap_eclipse_15Jan2010.mp4 swap_eclipse_11Jul2010.mp4
And we have a fifth channel at 17.4nm... ... called SWAP (using “SWAVINT”)
Jan - Sep 2010 SWAVINT and LYRA look quite similar LYRA shows flares in addition to EUV
SWAP and LYRA observing together 20100607_proba2_movie.mp4
Next steps • Cross-calibration (internal/external) • Produce calibrated data automatically (OK, but regular updates necessary) • Publish first results (in process) • Advertise data products • Get another extension from ESA (2012: OK)
How to be involved? Scientists are welcome to • use PROBA2 data • propose special observation campaigns Guest Investigator Program welcomes proposals for dedicated (joint) observations in the frame of a science project: • Funds available for a stay at PROBA2 Science Center • Scientist can take part in the commanding of the instruments • Will gain expertise in the instrumental effects • Next announcement (for 2011-12): May 2011 • Proposal deadline and selection: June 2011 • First visits: September 2011 onwards
Calibration 2010 according to TIMED/SEE