1 / 21

San Diego, SPIE August, 26 th 2007

ASPIICS on PROBA-3 Association de Satellites Pour l’Imagerie et l’Interférométrie de la Couronne Solaire. Sébastien Vives, Philippe Lamy Laboratoire d’Astrophysique de Marseille.

brac
Download Presentation

San Diego, SPIE August, 26 th 2007

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. ASPIICS on PROBA-3Association de Satellites Pour l’Imagerie et l’Interférométrie de la Couronne Solaire Sébastien Vives, Philippe Lamy Laboratoire d’Astrophysique de Marseille France: P. Levacher (LAM), M. Marcellin (LAM), S. Koutchmy (IAP), J. Arnaud (LUAN), E. Quemerais (SA), L. Damé (SA), R. Lallement (SA), J. C. Vial (IAS) UK: R. Harrisson (RAL), N.R. Waltham (RAL) Belgium: P. Rochus (CSL), J. M. Defise (CSL), D. Berghmans (ORB), J. F. Hochedez (ORB) Spain: J. Pacheco (ASRG/UAH), J. Blanco (ASRG/UAH) Portugal: J. M. Rebordao (INETI/LAER), D. Maia(INETI/LAER) Switzerland: W. Schmutz (PMOD/WRC), A. Benz (PMOD/WRC) Italy: G. Naletto San Diego, SPIE August, 26th 2007

  2. Proposed scientific Payload for PROBA-3 • The proposed scientific payload for the PROBA-3 mission is composed of: • ASPIICS: Association de Satellite Pour l’Imagerie et l’Interferometrie de la Couronne Solaire • a giant solar coronagraph to observe the middle corona with high spatial resolution and diagnostic (spectral) capability. • ARaSS: New generation Absolute Radiometer and Sun Sensor • ARaSS will contribute to the long-term measurement of the solar constant, and could possibly be operated beyond the nominal lifetime of the FF mission at very little cost. San Diego - SPIE

  3. Ground-based coronagraph: Low spatial resolution and atmospheric noise SOHO/LASCO-C2 R > 2.5 Rsol SOHO/LASCO-C1 High level of straylight and operated at solar minimum only Total solar Eclipses: Ideal but very rare and only a snapshot! Current observational status of the inner corona • After 40 years of space coronagraphy the lower corona (<2.5Rsol) remains practically unobserved • STEREO/COR-1 is also affected by large amounts of stray light and it needs an elaborated image reduction process to reveal bright structures from 1.4 Rsol. San Diego - SPIE

  4. ASPIICS objectives ASPIICS aims at achieving conditions close to total eclipses ASPIICS Field Of View Ground-based coronagraph SOHO/LASCO-C1 coronagraph SOHO/LASCO-C2 coronagraph Ground-based image obtained during a total solar eclipse San Diego - SPIE

  5. Scientific objectives • ASPIICS will offer a unique perspective to study processes occuring above 1.02 Rsun in both W-L and monochromatic ionic emissions. • ASPIICS will allow characterizing the main magnetic, dynamical and thermo-dynamical processes in the inner corona • ASPIICS will adress the following questions: • How is the corona heated? What is the role of waves? • How are the different components of the solar wind, slow and fast, accelerated? • To what degree do coronal inhomogeneities affect the heating and acceleration processes? • How are CMEs accelerated? • What is the nature of the interaction between the CME plasma and the magnetic field that drives the eruption? • What is the configuration of the magnetic field in the corona? San Diego - SPIE

  6. Performances are driven by the distance between the external occulter and the entrance pupil www.esa.int/proba What is ASPIICS ? • 2 S/C separated by 150 m realize a giant coronagraph and will achieve conditions close to a total solar eclipse San Diego - SPIE

  7. Unique Aspects of ASPIICS • Ambitious science objectives • Imaging the inner corona (1.075 - 3 Rsol) at high spatial resolution (<3arcsec/px) • Diagnostics of emission lines (velocity, turbulence, waves) • Topology of the coronal magnetic field • Operating in the visible • 3D spectroscopy of coronal emission lines • Simplicity • Optimum conditions • Drastic reduction of instrumental stray light • NO competitor in the coming 10-15 years San Diego - SPIE

  8. High resolution imaging… San Diego - SPIE

  9. … With unprecedented spatial resolution • White light imaging (540-630nm) • from 1.075 to 3 Rsun • at spatial resolution of 2.8 arcsec/px. Pixel limited Diffraction limited San Diego - SPIE

  10. Methodology: 3D-spectroscopy • Superimpose a system of fringes on the coronal image • Get all the spectral information in one image • Fe XIV: 5303 nm (coronal matter, 1.8x106 K) • Fe X: 637.4 nm (coronal holes, 1.0x106 K) • He I: 587.6 nm (cold matter, 1.0x105 K) • Tilt the F-P to displace the fringe pattern and improve the spatial coverage • Scientific quantities: • Ion densities (from intensities) • Temperatures (line broadening and comparison with W-L) • Velocities (Doppler shifts) • Turbulence (non thermal velocities) San Diego - SPIE

  11. Desai, Chandrasekhar & Angreji, 1981 ASPIICS with a Fabry-Perot (F-P) This solution has already been validated by several eclipse experiments on ground • Coronal interferogram on FeXIV emission line obtained during a total eclipse (Feb. 16th 1980) which has allowed to derive: • Intensity, Doppler shift, line broadening and splitting San Diego - SPIE

  12. Cover (door) L3 L1 L2 Internal occulter Polarizer F-P Detector Shutter Filter Wheel Conceptual Layout • Coronagraphic function: • The L1-objective re-images the occulting disk into the internal occulter to minimize straylight. • Spectro-polarimetric function: • The Fabry-Perot is located at the “Lyot stop” (pupil image) in a collimated beam after L2. • The polarizer is located in a collimated beam after L2. • Imaging function: • The L3-objective re-images the FOV onto a 2048x2048 CCD (15µm) San Diego - SPIE

  13. Optical Layout Entrance Pupil M1 Focal Plane M2 O3 O2 Fabry-Perot Blocking Filters Polarizer M3 Internal Occulter San Diego - SPIE

  14. Thermo-Mechanical Concept CCD radiator • The Coronagraph Optical Box (COB) appears as a parallelepiped in composite panels • The structure is decoupled from the S/C, mechanically and thermally, thanks to titanium bipods. • The thermal concept is based on both passive (MLI blanket) and active control (thermal lines). • The structure supports the CCD detector radiator by insulating spacers. CEB FPA M2 CCB CEB M1 CCB M3 San Diego - SPIE

  15. Absolute Displacement Error (ADE) Inter-Satellite Distance (ISD) FF Specifications • Inter-Satellite Distance (ISD) • ~ 150 m (±2 m variation over the year) • Absolute Displacement Error (ADE) • Lateral positioning: • ± 3.4mm (3s) with 20 arcsec APE • Can be relaxed to ± 6.0mm (3s) at the expense of the APE (8 arcsec) • Longitudinal positioning: ±740mm (3s) San Diego - SPIE

  16. Launch Configuration Coronagraph S/C Occulter S/C Lisa Path Finder Module Create/Delete FF Orbit and Launch • Baseline: 24h HEO • 800/70000 km • Inclination 63° • Visibility: 15-20 hrs/day • Eclipses (typical): from 0 to 3.9 hrs (180 days without eclipses per year) • Launch • 515 kg on a dedicated launch on VEGA/Verta launch (415 kg current) San Diego - SPIE

  17. PROBA-3/ASPIICS: programmatic 2009 2010 2011 2012 2006 2007 2008 Phase A Phase B Phases C/D ITT Operations Final Decision Launch San Diego - SPIE

  18. Step 2 Step 3 Darwin Xeus Aspiics 2008 2012 2015 2018 ASPIICS and Formation Flying missions Step 1 . • The • ASPIICS/PROBA-3 is a needed step toward most demanding future FF missions nanometer sub-arcsec mm arcsec Prisma cm arcmin San Diego - SPIE

  19. Conclusion • ASPIICS will address still unanswered science questions that the failed SOHO/LASCO-C1 coronagraph was supposed to investigate. Thanks to the following major improvements: • Straylight level: Externally occultation vs internally occultation • Spectral selection: Etalon Fabry-Perot vs Tunable • Strategy: Spatial vs spectral sampling • ASPIICS has no competitor in the coming 10-15 years • ASPIICS will give tremendous visibility to ESA's formation flying program thanks to spectacular results (movies of "explosions" are perfect for outreach) • ASPIICS will operate in synergy with contemplated disk imagers and wide field coronagraphs (SDO, SMESE, INTER-HELIOS, PROBA-2) • ASPIICS will help to prepare future formation flying missions San Diego - SPIE

  20. MERCI ! Thank You … San Diego - SPIE

  21. San Diego - SPIE

More Related