First Results from the LYRA Solar UV Radiometer J.-F. Hochedez, I. E. Dammasch, M. Dominique & the LYRA Team COSPAR 38 th Scientific Assembly Bremen July th Annual TIGER Symposium LYRA the Large-Yield Radiometer onboard PROBA2

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 LyHzAlZr Unit1MSMPINMSMSi Unit2MSMPINMSM Unit3SiPINSi

SWAP and LYRA spectral intervals for solar flares, space weather, and aeronomy LYRA channel 1: the H I nm Lyman-alpha line LYRA channel 2: the nm Herzberg continuum range LYRA channel 3: the nm Aluminium filter range including the He II 30.4 nm line (+ X-ray) LYRA channel 4: the 6-20 nm Zirconium filter range where solar variablility is highest (+ 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:

Summary: FITS File Structure lyra_ _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 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” (still preliminary):

LY-TMR: State of the data processing pipeline LY-EDG LY-BSDG Telemetry packets Raw data (in counts) Lv1: Engineering data (in Hz) fits Lv2: Calibrated data (in W/m²) Other tools Higher level data products Current stateIn the future Not distributed Daily basis After each contact Not available After each contact Plots + flare list available irregular systematic

First results (even before opening covers)

Aurora Oval  Perturbations appearing around 75° latitude  2-3 days after a CME, flare...  Associated to geomagnetic perturbations Spacecraft maneuvers SAA

First Light acquisition (06 Jan 2010)

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 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

M2.0 flare, 28 Feb 2010, 13:47 UTC

Comparison with GOES flare Example: M1.8 flare, 20 Jan 2010, 10:59 UTC

Sun-Moon eclipse …demonstrating the inhomogeneous distribution of EUV radiation across the solar surface

And we have a fifth channel at 17.4nm called SWAP!

SWAP and LYRA observing together _proba2_movie.mp4

Degradation of LYRA units 1 and 3

Initial degradation of LYRA unit 2 (nom.)

before & after (& still later) LYRA output, in kHz, incl. dark currents Ch1-1 Ch1-2 Ch1-3 Ch expected begin Jan end Apr 2010 Ch2-1 Ch2-2 Ch2-3 Ch2-4 (nominal unit) expected begin Jan end Apr 2010 Ch3-1 Ch3-2 Ch3-3 Ch expected begin Jan end Apr 2010

before & after (First Light) TIMED/SEE and SORCE/SOLSTICE spectra: nm W/m2 LYRA Radiometric Model simulation results with these spectra: ch1-1 ch1-2 ch1-3 ch nA ch2-1 ch2-2 ch2-3 ch nA ch3-1 ch3-2 ch3-3 ch nA LYRA planned level-2 calibration software results with real obs.: ch1-1 ch1-2 ch1-3 ch kHz nA W/m2 ch2-1 ch2-2 ch2-3 ch kHz nA W/m2 ch3-1 ch3-2 ch3-3 ch kHz nA W/m2

Model t = time {1,…,T} T = number of days s(t) = solar data l(t) = LYRA data c(t) = s(t)/l(t) conversion factor => s(i) = c(t)*l(i) {1,…, } simple expansion?? c(t) = b*d(t) degradation correction and conversion?? solar = a + b*lyra more realistic, see LRM, thus s(i) = a + b*d(t)*l(i) s(t) – a = b*d(t)*l(t) => T equations for T+2 variables

Procedure (instead of LRM) Get daily SORCE and TIMED data from the web Calculate degradation correction d(t) and expand with splines Calculate conversion parameters a and b Estimate dark current from past measurements, or from temperatures Estimate missing days with linear extrapolation of d(t) - currently only possible for channels 3 and 4

Next steps Understand degradation Cross-calibration (internal/external) Produce calibrated data automatically Publish first results Advertise data products Get extension from ESA … (suggestions?)