Helioseismic and Magnetic Imager for Solar Dynamics Observatory

ABSTRACT Helioseismic and Magnetic Imager for Solar Dynamics Observatory The primary goal of the Helioseismic and Magnetic Imager HMI Processing Pipeline and Standard Data Products (HMI) investigation is to study the origin of solar Philip Scherrer and HMI Team HMI Data Processing Data Product Science Objective variability and to characterize and understand the Sun's Processing Level 2 Data Product HMI Data InternalInternal rotation rotation Ω Ω(r,(r,ΘΘ)) Spherical Global Tachocline interior and the various components of magnetic activity. Heliographic Harmonic Mode frequencies (0Differential Rotation Full-diskFull-disk velocity, velocity, v(r,ΘΘ,Φ,Φ),), Near-Surface Shear Layer 1.B – Solar Dynamo Local wave AndAnd sound sound speed, speed, c (r,(r,ΘΘ,Φ,Φ),), Observatory (SDO) mission. HMI makes measurements of The primary goal of the Helioseismic and Magnetic Imager (HMI) investigation is to Ring diagrams Local s Maps (0-30Mm) the motion of the solar photosphere to study solar 1.J – Sunspot Dynamics 1.C – Global Circulation Doppler Helioseismologyfrequency shifts Maps (0-30Mm) Activity Complexes study the origin of solar variability and to characterize and understand the Sun’s interior Velocity Processing CarringtonCarrington synoptic synoptic v andand c c Time-distance s s Active Regions oscillations and measurements of the polarization in a Tracked Tiles mapsmaps (0-30Mm) (0-30Mm) and the various components of magnetic activity. The HMI investigation is based on Cross-covariance Wave travel times Level-1 Of Dopplergrams Sunspots spectral line to study all three components of the function High-resolutionHigh-resolution v v and and c c measurements obtained with the HMI instrument as part of the Solar Dynamics ss photospheric magnetic field. Here we will give an overview Observables mapsmaps (0-30Mm) (0-30Mm) Irradiance Variations Egression and Wave phase Observatory (SDO) mission. HMI makes measurements of the motion of the solar Magnetic Shear of the HMI science goals, the HMI instrument and its Ingression mapsDoppler shift maps Deep-focusDeep-focus v v and and c css expected performance, the science products produced and photosphere to study solar oscillations and measurements of the polarization in a spectral Velocity mapsmaps (0-200Mm) (0-200Mm) Flare Magnetic Config. the ways in which the science community and public will line to study all three components of the photospheric magnetic field. HMI produces data 1.I – Magnetic Connectivity Stokes Line-of-sight Far-sideFar-side activity activity index index Flux Emergence 1.A – Interior Structure I,V Magnetograms Line-of-sight -1 Line-of-Sight Magnetic Carpet be able to utilize HMI data. to determine the interior sources and mechanisms of solar variability and how the physical v (km s ) 1.4 Magnetograms Line-of-Sight Magnetic Field Maps Magnetic Field Maps Coronal energetics processes inside the Sun are related to surface magnetic field and activity. It also produces -1.4 Stokes Full-disk 10-min Vector Magnetograms Vector Magnetic 1.D – Irradiance Sources I,Q,U,V Averaged maps Vector Fast algorithm Vector Magnetic Large-scale Coronal Fields 2.0 Field Maps See: http://hmi.stanford.edu for more information. data to enable estimates of the coronal magnetic field for studies of variability in the B (kG) Magnetograms Field Maps Solar Wind Vector Magnetograms -2.0 CoronalCoronal magnetic magnetic extended solar atmosphere. HMI observations will enable establishing the relationships Tracked Tiles Inversion algorithm Continuum FieldField Extrapolations Extrapolations Far-side Activity Evolution between the internal dynamics and magnetic activity in order to understand solar 1.0 Flux (kG) Tracked full-disk Brightness Coronal and Predicting A-R Emergence Continuum Coronal and 1-hour averaged Solar limb parameters Solar wind models variability and its effects, leading to reliable predictive capability, one of the key elements -1.5 Brightness Solar wind models IMF Bs Events Continuum maps of the Living With a Star (LWS) program. Ic Level-1 Brightness feature BrightnessBrightness Images Images to disk center maps

The broad goals described above will be addressed in a coordinated investigation in a 10Mm 1.E – Coronal Magnetic Field number of parallel studies. These segments of the HMI investigation are to observe and 1.H – Far-side Imaging HMI and AIA Joint Science Operations Center (JSOC) understand these interlinked processes: The Science Data Processing (SDP) for HMI and AIA will be done at Stanford and LMSAL. The Joint Operations Center (JOC) will be at LMASL. For the SDP the Capture, pipeline processing, archive, and Distribution will be HOP – HMI Optics Package • Convection-zone dynamics and the solar dynamo; located at Stanford. The higher level AIA products will be at LMSAL. The higher level HMI products will be • Origin and evolution of sunspots, active regions and complexes of activity; computed at Stanford. GSFC • Sources and drivers of solar activity and disturbances; White Sands LMSAL HEB – HMI • Links between the internal processes and dynamics of the corona and heliosphere; 1.G – Magnetic Stresses 1.F – Solar Subsurface Weather ping MOC Electronics Box DDS ekee • Precursors of solar disturbances for space-weather forecasts. hous Stanford HMI & AIA House- These goals address long-standing problems that can be studied by a number of immediate Operations The Solar Dynamics Observatory will be placed into an inclined JSOC Pipeline Processing keeping System Geosynchronous orbit to maximize sunlit hours while providing tasks. The description of these tasks reflects our current level of understanding and will Redundant Database HMI/AIA Level-0, 1, Data high bandwidth telemetry. Launch in late summer 2008. obviously evolve in the course of the investigation. HMI-level2 Quicklook Capture Viewing System

Primary LWS / SDO 1.A) Sound speed variations relative to a standard solar model. HMI Science Team 30-Day Archive AIA “Poster 1.B) Solar cycle variations in the sub-photospheric rotation rate. Local Analysis Archive Catalog HMI is a joint project of the Stanford University Hansen Experimental Physics Laboratory and Picture” 1.C) Solar meridional circulation and differential rotation. Archive System Lockheed-Martin Solar and Astrophysics Laboratory with key contributions from the High Altitude shows 1.D) Sunspots and plage contribute to solar irradiance variation. Observatory, and the HMI Science Team. All HMI data is available to all investigators as well as those High-Level HMI goal 1.E) MHD model of the magnetic structure of the corona. Data Import Data in the initial team. 1.F) Synoptic map of the subsurface flows at a depth of 7 Mm. Offsite World Offline Export Archive Name Role Institution Phase B,C,D Phase-E 1.G) EIT image and magnetic field lines computed from the photospheric field. Archive & Web Science Team Forecast Centers Philip H. Scherrer PI Stanford University HMI Investigation Solar Science 1.H) Active regions on the far side of the sun detected with helioseismology. Service Sound-speed beneath a sunspot ( +, red, and -, blue EPO John G. Beck A-I Stanford University E/PO Science Liaison Surface Flows 1.I) Vector field image showing the magnetic connectivity in sunspots. Public Richard S. Bogart Co-I Stanford University Data Pipeline and Access Near Surface Flows perturbations) from SOHO/MDI high-resolution data. 1.J) Sound speed variations and flows in an emerging active region. Rock I. Bush Co-I Stanford University Program Manager Irradiance and Shape Thomas L. Duvall, Jr. Co-I NASA Goddard Space Flight Center Time-Distance Code Helioseismology Alexander G. Kosovichev Co-I Stanford University Inversion Code Helioseismology HMI Implementation Yang Liu A-I Stanford University Vector Field Observable Code Active Region Fields HMI Observables Jesper Schou Co-I Stanford University Instrument Scientist Helioseismology The HMI instrument design and observing strategy are based on the highly successful Doppler Velocity Vector Magnetic Field Xue Pu Zhao Co-I Stanford University Coronal Code Coronal Field Models MDI instrument, with several important improvements. HMI will observe the full solar Cadence 45 s Cadence 90 s Alan M. Title Co-I LMSAL HMI Instrument Solar Science disk in the Fe I absorption line at 6173Åwith a resolution of 1 arc-second. HMI consists Precision 13 m/s Precision: Thomas Berger A-I LMSAL * Vector Field Calibration Active Region Science of a refracting telescope, a polarization selector, an image stabilization system, a narrow Zero point accuracy 0.05 m/s Polarization 0.22% Thomas R. Metcalf Co-I LMSAL * Vector Field Calibration Active Region Science band tunable filter and two 4096² pixel CCD cameras with mechanical shutters and Dynamic range ±6.5 km/s Sunspots (1kG<|B|<4kG) * Carolus J. Schrijver Co-I LMSAL AIA Liaison Active Region Science control electronics. The data rate is 55Mbits/s. Theodore D. Tarbell Co-I LMSAL HMI Calibration Active Region Science Line-of-Sight Magnetic Flux |B| 18G Bruce W. Lites A-I High Altitude Observatory * Vector Field Inversions Active Region Science Cadence 45 s Azimuth 0.6º The polarization selector, a set of rotating waveplates, enables measurement of Stokes I, Steven Tomczyk Co-I High Altitude Observatory * Vector Field Inversions Active Region Science Precision 10 G Inclination 1.4º Q, U and V with high polarimetric efficiency. The tunable filter, a Lyot filter with one Sarbani Basu Co-I Yale University * Ring Analysis Code Helioseismology Zero point accuracy 0.05 G Quiet Sun (0.1kG<|B|<2kG) * tunable element and two tunable Michelson interferometers, has a tuning range of 600 Douglas C. Braun Co I Colorado Research Associates * Farside Imaging Code Helioseismology Dynamic range ± 4 kG |B| 220 G mÅ and a FWHM filter profile of 76 mÅ. Philip R. Goode Co-I NJIT, Big Bear Solar Observatory * Magnetic and Helioseismic Code Fields & Helioseismology Continuum Intensity Total flux density 35 G Frank Hill Co-I National Solar Observatory * Ring Analysis Code Helioseismology Cadence 45 s Azimuth 15º Images are made in a sequence of tuning and polarizations at a 4-second cadence for each Rachel Howe Co-I National Solar Observatory * Internal Rotation Inversion Code Helioseismology The solid lines show the HMI filter transmission profiles at 76 mÅ Precision 0.3% Inclination 18º camera. One camera is dedicated to a 45s Doppler and line-of-sight field sequence while Jeffrey R. Kuhn Co-I University of Hawaii * Limb and Irradiance Code Irradiance and Shape spacing. The black dashed line is the profile used for the continuum Accuracy pixel to pixel 0.1% * See Figure C.12 for details the other to a 90s vector field sequence. All of the images are downlinked for processing Charles A. Lindsey Co-I Colorado Research Associates * Farside Imaging Code Helioseismology filtergram. The dotted line shows the Fe I line profile. at the HMI/AIA Joint Science Operations Center at Stanford University. Jon A. Linker Co-I Science Applications Intnl. Corp. * Coronal MHD Model Code Coronal Physics N. Nicolas Mansour Co-I NASA Ames Research Center * Convection Zone MHD Model Code Convection Physics Edward J. Rhodes, Jr. Co-I University of Southern California * Helioseismic Analysis Code Helioseismology Juri Toomre Co-I JILA, Univ. of Colorado * Sub-Surface-Weather Code Helioseismology 7 Hollow Core Motors HMI Principal Optics Package Components Z Roger K. Ulrich Co-I University of California, Los Angeles * Magnetic Field Calibration Code Solar Cycle 5 sta ge Fold Mirror Assembly Alan Wray Co-I NASA Ames Research Center * Convection Zone MHD Model Code Convection Physics Lyot filter J. Christensen-Dalsgaard Co-I TAC, Aarhus University, DK * Solar Model Code Helioseismology 2 Focus/Cal Wheels X BDS Beam-splitter Assembly Focal Plane Assembly J. Leonard Culhane Co-I MSSL, University College London, UK Active Region Science Y Michelson Interferometer Bernhard Fleck Co-I European Space Agency ILWS Coordination Atmospheric Dynamics ISS Beam-splitter Douglas O. Gough Co-I IoA, Cambridge University, UK * Local HS Inversion Code Helioseismology Assembly Alignment Mechanism Richard A. Harrison Co-I Rutherford Appleton Laboratories, UK Active Region Science Limb Sensor Assembly Takashi Sekii Co-I National Astron. Obs. of Japan, JP Helioseismology Filter Oven Assembly Hiromoto Shibahashi Co-I University of Tokyo, JP Helioseismology ISS Pre-Amp Electronics Lyot Filter Assembly Sami K. Solanki Co-I Max-Planck-Institut für Aeronomie, DE AR Science Box Michael J. Thompson Co-I Imperial College, UK Helioseismology Oven Controller E-Box Camera Electronics Box HMI Science Team * Phase D only Focus Mechanism Telescope Assembly ISS Mirror Assembly The HMI E/PO program is implemented as part of the Stanford SOLAR Center at Primary Lens Assembly Hollow Core Motors Stanford University. http://solar-center.stanford.edu Front Window Assembly Secondary Lens Assembly HMI Education/Public Outreach Partnerships Front Door Assembly Distribution of Development Development Structure Involvement Undeserved Curriculum Curriculum Multimedia Assessment Workshops education infomal Public/ Materials Access to

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Optical Characteristics: * For AIA Effective Focal Length: 495 cm Filter Characteristics: Telescope Clear Aperture: 14 cm Central Wavelength: 617.3 nm Mechanical Characteristics: Stanford X X X X X X X X X Focal Ratio: f/35.4 Reject 99% Solar Heat Load Box: 0.84 × 0.55 × 0.16 m LMSAL X X X X X X Final Image Scale: 24 µm / arcsec Bandwidth: 0.0076 nm Over All: 1.19 × 0.83 × 0.30 m Re-imaging Lens Magnification: 2 Tunable Range: 0.05 nm Stanford-Haas X X X X X Mass: 42.15 kg Focus Adjustment Range: 16 steps of 1 mm Free Spectral Range: 0.0688 nm First Mode: 73 Hz MSU* X X X X X X X X X SAO* X X X X X X X X X The Tech Museum X X X X X 2 Shutters Chabot SSC X X X X X Structure model Morrison Planetarium X X X X HMI Optics Box /CA Academy of (left) Sciences Lawrence Hall of X X X X X Brassboard Science 2 40962 CCDs electronics box IIISE X X actual size under test (right). NASA-CORE X