Transcript Slide 1

Helioseismic and Magnetic Imager for Solar Dynamics Observatory
ABSTRACT
The primary goal of the Helioseismic and Magnetic Imager
(HMI) investigation is to study the origin of solar
variability and to characterize and understand the Sun's
interior and the various components of magnetic activity.
The HMI investigation is based on measurements obtained
with the HMI instrument as part of the Solar Dynamics
Observatory (SDO) mission. HMI makes measurements of
the motion of the solar photosphere to study solar
oscillations and measurements of the polarization in a
spectral line to study all three components of the
photospheric magnetic field. Here we will give an overview
of the HMI science goals, the HMI instrument and its
expected performance, the science products produced and
the ways in which the science community and public will
be able to utilize HMI data.
HMI Processing Pipeline and Standard Data Products
Philip Scherrer and HMI Team
HMI
Data
Processing
HMI Data
HMI Major Science Objectives
Filtergrams
Level-0
1.B – Solar Dynamo
The primary goal of the Helioseismic and Magnetic Imager (HMI) investigation is to
study the origin of solar variability and to characterize and understand the Sun’s interior
and the various components of magnetic activity. The HMI investigation is based on
measurements obtained with the HMI instrument as part of the Solar Dynamics
Observatory (SDO) mission. HMI makes measurements of the motion of the solar
photosphere to study solar oscillations and measurements of the polarization in a spectral
line to study all three components of the photospheric magnetic field. HMI produces data
to determine the interior sources and mechanisms of solar variability and how the physical
processes inside the Sun are related to surface magnetic field and activity. It also produces
data to enable estimates of the coronal magnetic field for studies of variability in the
extended solar atmosphere. HMI observations will enable establishing the relationships
between the internal dynamics and magnetic activity in order to understand solar
variability and its effects, leading to reliable predictive capability, one of the key elements
of the Living With a Star (LWS) program.
See: http://hmi.stanford.edu for more information.
1.J – Sunspot Dynamics
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HEB – HMI
Electronics Box
1.C – Global Circulation
Tracked Tiles
Of Dopplergrams
Data
Product
Level
2 Data
Product
Global
Mode
frequencies
Helioseismology
And splitting
Processing
Local
Localwave
frequency
shifts
Helioseismology
Ring diagrams
Doppler
Velocity
Level-1
Time-distance
Cross-covariance
function
Processing
Wave travel times
Ingression maps
Doppler shift maps
Velocity
1.I – Magnetic Connectivity
1.A – Interior Structure
1.D – Irradiance Sources
Stokes
I,V
Line-of-sight
Magnetograms
Stokes
I,Q,U,V
Full-disk 10-min
Averaged maps
Line-of-sight
Magnetograms
Vector Magnetograms
Vector Fast algorithm
Magnetograms
Vector Magnetograms
Inversion algorithm
Tracked Tiles
Continuum
Brightness
Tracked full-disk
1-hour averaged
Continuum maps
Continuum
Brightness
Level-1
Internalrotation
rotationΩ(r,Θ)
Ω(r,Θ)
Internal
(0<r<R)
(0<r<R)
Meridional Circulation
Carrington
andcscs
Carringtonsynoptic
synoptic vv and
maps(0-30Mm)
(0-30Mm)
maps
Active Regions
1.H – Far-side Imaging
HMI is a joint project of the Stanford University Hansen Experimental Physics Laboratory and
Lockheed-Martin Solar and Astrophysics Laboratory with key contributions from the High Altitude
Observatory, and the HMI Science Team. All HMI data is available to all investigators as well as those
in the initial team.
Name
Role
Institution
Phase B,C,D
Phase-E
Philip H. Scherrer
PI
Stanford University
HMI Investigation
Solar Science
John G. Beck
A-I
Stanford University
E/PO Science Liaison
Surface Flows
Richard S. Bogart
Co-I
Stanford University
Data Pipeline and Access
Near Surface Flows
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
Yang Liu
A-I
Stanford University
Vector Field Observable Code
Active Region Fields
Jesper Schou
Co-I
Stanford University
Instrument Scientist
Helioseismology
Xue Pu Zhao
Co-I
Stanford University
Coronal Code
Coronal Field Models
Alan M. Title
Co-I
LMSAL
HMI Instrument
Solar Science
Thomas Berger
A-I
LMSAL
* Vector Field Calibration
Active Region Science
Thomas R. Metcalf
Co-I
LMSAL
* Vector Field Calibration
Active Region Science
Carolus J. Schrijver
Co-I
LMSAL
AIA Liaison
Active Region Science
Theodore D. Tarbell
Co-I
LMSAL
HMI Calibration
Active Region Science
Bruce W. Lites
A-I
High Altitude Observatory
* Vector Field Inversions
Active Region Science
Steven Tomczyk
Co-I
High Altitude Observatory
* Vector Field Inversions
Active Region Science
Sarbani Basu
Co-I
Yale University
* Ring Analysis Code
Helioseismology
Douglas C. Braun
Co I
Colorado Research Associates
* Farside Imaging Code
Helioseismology
Philip R. Goode
Co-I
NJIT, Big Bear Solar Observatory
* Magnetic and Helioseismic Code
Fields & Helioseismology
Frank Hill
Co-I
National Solar Observatory
* Ring Analysis Code
Helioseismology
Rachel Howe
Co-I
National Solar Observatory
* Internal Rotation Inversion Code
Helioseismology
Jeffrey R. Kuhn
Co-I
University of Hawaii
* Limb and Irradiance Code
Irradiance and Shape
Charles A. Lindsey
Co-I
Colorado Research Associates
* Farside Imaging Code
Helioseismology
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
Roger K. Ulrich
Co-I
University of California, Los Angeles
* Magnetic Field Calibration Code
Solar Cycle
Alan Wray
Co-I
NASA Ames Research Center
* Convection Zone MHD Model Code
Convection Physics
J. Christensen-Dalsgaard
Co-I
TAC, Aarhus University, DK
* Solar Model Code
Helioseismology
J. Leonard Culhane
Co-I
MSSL, University College London, UK
Bernhard Fleck
Co-I
European Space Agency
ILWS Coordination
Atmospheric Dynamics
Douglas O. Gough
Co-I
IoA, Cambridge University, UK
* Local HS Inversion Code
Helioseismology
Richard A. Harrison
Co-I
Rutherford Appleton Laboratories, UK
Active Region Science
Takashi Sekii
Co-I
National Astron. Obs. of Japan, JP
Helioseismology
Hiromoto Shibahashi
Co-I
University of Tokyo, JP
Helioseismology
Sami K. Solanki
Co-I
Max-Planck-Institut für Aeronomie, DE
AR Science
Michael J. Thompson
Co-I
Imperial College, UK
Helioseismology
Sound-speed beneath a sunspot ( +, red, and -, blue
perturbations) from SOHO/MDI high-resolution data.
Activity Complexes
Sunspots
Solar limb parameters
Brightness feature
maps
Irradiance Variations
Deep-focus
Deep-focusvvand
andccs s
maps
maps(0-200Mm)
(0-200Mm)
Magnetic Shear
Far-side
Far-sideactivity
activityindex
index
Flux Emergence
Line-of-Sight
Line-of-Sight
Magnetic
MagneticField
FieldMaps
Maps
Magnetic Carpet
Flare Magnetic Config.
Coronal energetics
Vector
VectorMagnetic
Magnetic
Field
FieldMaps
Maps
Large-scale Coronal Fields
Solar Wind
Coronal
Coronalmagnetic
magnetic
Field
FieldExtrapolations
Extrapolations
Far-side Activity Evolution
Predicting A-R Emergence
Coronal
Coronaland
and
Solar
Solarwind
windmodels
models
IMF Bs Events
Brightness
BrightnessImages
Images
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
located at Stanford. The higher level AIA products will be at LMSAL. The higher level HMI products will be
computed at Stanford.
GSFC
White Sands
1.G – Magnetic Stresses
LMSAL
1.F – Solar Subsurface Weather
MOC
DDS
1.A) Sound speed variations relative to a standard solar model.
1.B) Solar cycle variations in the sub-photospheric rotation rate.
1.C) Solar meridional circulation and differential rotation.
1.D) Sunspots and plage contribute to solar irradiance variation.
1.E) MHD model of the magnetic structure of the corona.
1.F) Synoptic map of the subsurface flows at a depth of 7 Mm.
1.G) EIT image and magnetic field lines computed from the photospheric field.
1.H) Active regions on the far side of the sun detected with helioseismology.
1.I) Vector field image showing the magnetic connectivity in sunspots.
1.J) Sound speed variations and flows in an emerging active region.
Housekeeping
Database
Quicklook
Viewing
Primary
Archive
30-Day
Archive
Offsite
Archiv
e
High-Level
Data Import
Data
Export
& Web
Service
Offline
Archiv
e
AIA
Analysis
System
Local
Archive
Catalog
HMI Implementation
World
Science Team
Forecast Centers
EPO
Public
HMI Observables
The HMI instrument design and observing strategy are based on the highly successful
MDI instrument, with several important improvements. HMI will observe the full solar
disk in the Fe I absorption line at 6173Åwith a resolution of 1 arc-second. HMI consists
of a refracting telescope, a polarization selector, an image stabilization system, a narrow
band tunable filter and two 4096² pixel CCD cameras with mechanical shutters and
control electronics. The data rate is 55Mbits/s.
Doppler Velocity
Cadence
Vector Magnetic Field
45 s
Cadence
Precision
13 m/s
Zero point accuracy
0.05 m/s
Dynamic range
±6.5 km/s
Line-of-Sight Magnetic Flux
Cadence
45 s
Precision
10 G
The polarization selector, a set of rotating waveplates, enables measurement of Stokes I,
Q, U and V with high polarimetric efficiency. The tunable filter, a Lyot filter with one
tunable element and two tunable Michelson interferometers, has a tuning range of 600
mÅ and a FWHM filter profile of 76 mÅ.
Images are made in a sequence of tuning and polarizations at a 4-second cadence for each
camera. One camera is dedicated to a 45s Doppler and line-of-sight field sequence while
the other to a 90s vector field sequence. All of the images are downlinked for processing
at the HMI/AIA Joint Science Operations Center at Stanford University.
HMI & AIA
Operations
JSOC Pipeline Processing
System
HMI/AIA Level-0, 1,
HMI-level2
Redundant
Data
Capture
System
The solid lines show the HMI filter transmission profiles at 76 mÅ
spacing. The black dashed line is the profile used for the continuum
filtergram. The dotted line shows the Fe I line profile.
Zero point accuracy
0.05 G
Dynamic range
± 4 kG
Continuum Intensity
Cadence
45 s
Precision
0.3%
Accuracy pixel to pixel
0.1%
90 s
Precision:
Polarization
Sunspots (1kG<|B|<4kG) *
|B|
Azimuth
Inclination
Quiet Sun (0.1kG<|B|<2kG) *
|B|
Total flux density
Azimuth
Inclination
0.22%
18G
0.6º
1.4º
220 G
35 G
15º
18º
* See Figure C.12 for details
HMI Principal Optics Package Components
7 Hollow Core Motors
Z
Fold Mirror Assembly
2 Focus/Cal Wheels
Active Region Science
HMI Science Team
Near-Surface Shear Layer
HMI and AIA Joint Science Operations Center (JSOC)
These goals address long-standing problems that can be studied by a number of immediate
tasks. The description of these tasks reflects our current level of understanding and will
obviously evolve in the course of the investigation.
LWS / SDO
“Poster
Picture”
shows
HMI goal
Differential Rotation
1.E – Coronal Magnetic Field
Convection-zone dynamics and the solar dynamo;
Origin and evolution of sunspots, active regions and complexes of activity;
Sources and drivers of solar activity and disturbances;
Links between the internal processes and dynamics of the corona and heliosphere;
Precursors of solar disturbances for space-weather forecasts.
HMI Science Team
Tachocline
Internal
Internalsound
soundspeed,
speed,
ccs(r,Θ)
(0<r<R)
s(r,Θ)(0<r<R)
Full-disk
velocity,
Full-disk
velocity, v(r,Θ,Φ),
v(r,Θ,Φ),
soundspeed,
speed, css(r,Θ,Φ),
AndAnd
sound
(r,Θ,Φ),
Maps
(0-30Mm)
Maps (0-30Mm)
Stanford
The Solar Dynamics Observatory will be placed into an inclined
Geosynchronous orbit to maximize sunlit hours while providing
high bandwidth telemetry. Launch in late summer 2008.
Science Objective
High-resolution
High-resolutionvvand
andccs s
maps
maps(0-30Mm)
(0-30Mm)
Observables
Egression and
Wave phase
The broad goals described above will be addressed in a coordinated investigation in a
number of parallel studies. These segments of the HMI investigation are to observe and
understand these interlinked processes:
HOP – HMI Optics
Package
Spherical
Harmonic
Time series
To l=1000
Filtergrams
Heliographic
Doppler velocity
maps
Processing
Focal Plane Assembly
BDS Beam-splitter Assembly
X
Y
Michelson Interferometer
ISS Beam-splitter
Assembly
Alignment Mechanism
Limb Sensor Assembly
Filter Oven Assembly
ISS Pre-Amp Electronics
Box
Lyot Filter Assembly
Oven Controller E-Box
Camera Electronics Box
* Phase D only
Focus Mechanism
Telescope Assembly
ISS Mirror Assembly
Primary Lens Assembly
The HMI E/PO program is implemented as part of the Stanford SOLAR Center at
Stanford University.
http://solar-center.stanford.edu
Hollow Core Motors
Front Window Assembly
Secondary Lens Assembly
Front Door Assembly
HMI Education/Public Outreach Partnerships
Assessment
Support
Multimedia
Development
Distance
Learning
Support
X
X
X
X
X
LMSAL
X
X
Stanford-Haas
X
MSU*
X
X
SAO*
X
X
The Tech Museum
X
Chabot SSC
Morrison Planetarium
/CA Academy of
Sciences
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Lawrence Hall of
Science
X
IIISE
X
NASA-CORE
X
Public/
infomal
education
Teacher
Workshops
X
Access to
Undeserved
K-14
Curriculum
Development
Stanford
* For AIA
Structure
Distribution of
Materials
Student
Involvement
Institution
X
X
X
Optical Characteristics:
Effective Focal Length: 495 cm
Telescope Clear Aperture: 14 cm
Focal Ratio: f/35.4
Final Image Scale: 24 µm / arcsec
Re-imaging Lens Magnification: 2
Focus Adjustment Range: 16 steps of 1 mm
2 Shutters
Structure model
HMI Optics Box
(left)
X
X
2
X
X
Filter Characteristics:
Central Wavelength: 617.3 nm
Reject 99% Solar Heat Load
Bandwidth: 0.0076 nm
Tunable Range: 0.05 nm
Free Spectral Range: 0.0688 nm
40962
CCDs
actual size
Brassboard
electronics box
under test (right).
Mechanical Characteristics:
Box: 0.84 × 0.55 × 0.16 m
Over All: 1.19 × 0.83 × 0.30 m
Mass: 42.15 kg
First Mode: 73 Hz