HMI Status
P. Scherrer
LWS Teams Meeting, March 2008
Page 1
HMI Primary goal
Origin of Solar Variability
• 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.
• 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 and coronal magnetic fields and activity.
LWS Teams Meeting, March 2008
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HMI Instrument on SDO
SDO
AIA
•
HMI Instrument
– HMI Optics Package (HOP)
EVE
X
– HMI Electronics Box (HEB)
Y
– Intra Instrument Harness
Z
– Flight Software
HMI
Z
Y
X
LWS Teams Meeting, March 2008
HOP
HEB
Page 3
All moved in!
HOP
HEB
Harness
LWS Teams Meeting, March 2008
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HMI is Ready
•
The HMI instrument was delivered to NASA last November
•
HMI is integrated onto SDO
•
HMI will meet “Level-1” observing requirements
•
It is a fine instrument, we are very pleased with it
•
There are a few minor issues that must and will be resolved in the
coming month or two, e.g.:
– A few flight software issues expected to be resolved by May
– Front window birefringence change with temperature to be explored with spare
•
There are a few minor issues that will be resolved after launch, e.g:
– Temperature control method and variations during orbit
– Tuning parameters for data compression - variations with tuning and polarization
•
There are a few items to be determined after launch, e.g.:
– “Best” framelist for observing sequence
– Can we combine data from both cameras to compute “Observables”
– The internal structure and dynamics of the Sun and the sources of solar variability
LWS Teams Meeting, March 2008
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So, the first 6 years work of many got the instrument done
but we are not yet ready for data to flow or to accomplish the science..
LWS Teams Meeting, March 2008
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Primary Science Objectives
1.
2.
3.
4.
5.
Convection-zone dynamics and solar dynamo
–
Structure and dynamics of the tachocline
–
Variations in differential rotation.
–
Evolution of meridional circulation.
–
Dynamics in the near-surface shear layer.
Origin and evolution of sunspots, active regions and complexes of activity
–
Formation and deep structure of magnetic complexes.
–
Active region source and evolution.
–
Magnetic flux concentration in sunspots.
–
Sources and mechanisms of solar irradiance variations.
Sources and drivers of solar activity and disturbances
–
Origin and dynamics of magnetic sheared structures and delta-type sunspots.
–
Magnetic configuration and mechanisms of solar flares and CME.
–
Emergence of magnetic flux and solar transient events.
–
Evolution of small-scale structures and magnetic carpet.
Links between the internal processes and dynamics of the corona and heliosphere
–
Complexity and energetics of solar corona.
–
Large-scale coronal field estimates.
–
Coronal magnetic structure and solar wind
Precursors of solar disturbances for space-weather forecasts
–
Far-side imaging and activity index.
–
Predicting emergence of active regions by helioseismic imaging.
–
Determination of magnetic cloud Bs events.
LWS Teams Meeting, March 2008
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HMI Science Analysis Plan
HMI Data
Processing
Data Product
Science Objective
Global
Helioseismology
Processing
Internal rotation Ω(r,Θ)
(0<r<R)
Tachocline
Internal sound speed,
cs(r,Θ) (0<r<R)
Differential Rotation
Local
Helioseismology
Processing
Full-disk velocity, v(r,Θ,Φ),
And sound speed, cs(r,Θ,Φ),
Maps (0-30Mm)
Activity Complexes
Filtergrams
Carrington synoptic v and cs
maps (0-30Mm)
Observables
Doppler
Velocity
High-resolution v and cs
maps (0-30Mm)
Deep-focus v and cs
maps (0-200Mm)
Far-side activity index
Line-of-sight
Magnetograms
Vector
Magnetograms
Continuum
Brightness
Line-of-Sight
Magnetic Field Maps
Near-Surface Shear Layer
Active Regions
Sunspots
Irradiance Variations
Magnetic Shear
Flare Magnetic Configuration
Flux Emergence
Magnetic Carpet
Coronal energetics
Vector Magnetic
Field Maps
Large-scale Coronal Fields
Coronal magnetic
Field Extrapolations
Far-side Activity Evolution
Coronal and
Solar wind models
Brightness Images
LWS Teams Meeting, March 2008
Meridional Circulation
Solar Wind
Predicting A-R Emergence
IMF Bs Events
Version 1.0w
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HMI Standard Product Pipeline
Processing
HMI Data
Heliographic
Doppler velocity
maps
Filtergrams
Level-0
Doppler
Velocity
Spherical
Harmonic
Time series
To l=1000
Mode frequencies
And splitting
Ring diagrams
Local wave
frequency shifts
Time-distance
Tracked Tiles
Cross-covariance
Of Dopplergrams
function
Egression and
Ingression maps
Level-1
Data Product
Wave travel times
Wave phase
shift maps
Internal rotation Ω(r,Θ)
(0<r<R)
Internal sound speed,
cs(r,Θ) (0<r<R)
Full-disk velocity, v(r,Θ,Φ),
And sound speed, cs(r,Θ,Φ),
Maps (0-30Mm)
Carrington synoptic v and cs
maps (0-30Mm)
High-resolution v and cs
maps (0-30Mm)
Deep-focus v and cs
maps (0-200Mm)
Far-side activity index
Stokes
I,V
Line-of-sight
Magnetograms
Stokes
I,Q,U,V
Full-disk 10-min
Averaged maps
Vector Magnetograms
Fast algorithm
Tracked Tiles
Vector Magnetograms
Inversion algorithm
Coronal magnetic
Field Extrapolations
Tracked full-disk
1-hour averaged
Continuum maps
Solar limb parameters
Coronal and
Solar wind models
Brightness feature
maps
Brightness Images
Continuum
Brightness
HMI Data Analysis Pipeline
LWS Teams Meeting, March 2008
Line-of-Sight
Magnetic Field Maps
Vector Magnetic
Field Maps
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Status of HMI Science Processing Plan Development
•
•
Data analysis pipeline: standard helioseismology and magnetic field
analyses will produce “Standard” data products
“Level-1” Observable program development just now getting started.
•
•
•
•
None of the “pipelines” are functioning yet.
Most pipeline elements need updated software.
Targeted numerical modeling is proceeding.
Focused data analysis and science working groups continue to be
important.
•
•
Joint investigations with AIA and EVE need development.
Cooperation with other space- and ground-based projects (SOHO,
Hinode, PICARD, STEREO, RHESSI, GONG+, SOLIS, HELAS) needs
development.
After this meeting we will evaluate which pipeline elements must proceed
with existing algorithms and code and which will get improvements.
•
•
It is clear that “standard products” will evolve early in the mission.
LWS Teams Meeting, March 2008
Page 10
Summary
•
The HMI Instrument is ready to provide key data to study the Sun’s
dynamics and magnetism: subsurface flow maps and photospheric vector
magnetic fields.
•
There are some minor issues, some will be fixed and some we will live with.
•
It needs to be in the sky.
•
The HMI data analysis plan includes a standard pipeline processing and on
demand data analysis tools.
•
The analysis pipeline is being developed by the Co-I team, using existing
techniques and software.
•
Since many Co-Is do not have funding to prepare, some of the planned data
products may not be available at the start of the mission.
•
Many “Traditional” data product pipelines will be ready if the present rate of
development continues.
•
Work on the “white boxes” will likely wait until after launch.
LWS Teams Meeting, March 2008
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DONE
More Details on HMI status follow
LWS Teams Meeting, March 2008
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HMI status
•
•
Completed mechanical integration with the SDO spacecraft
–
Optics package alignment is within the requirement
–
MLI closeout was completed (except for a couple access points)
Completed electrical integration
–
Discovered low LVDS isolation resistance which indicated ESD damage to LVDS
–
Completed LVDS rework (see “Changes Since PSR” chart)
•
HMI completed the stand alone CPT and the observatory CPT#1
•
HMI hardware is in flight configuration with the following exceptions
–
Flight software update is planned prior to CPT#2
–
Need to stake the MLI around the front door
–
Closeout MLI around alignment cube
–
Remove red tag items
LWS Teams Meeting, March 2008
Page 13
Flight Software Status
•
Delivered FSW with known issues and planned software update at observatory
–
Developed a list of software updates with SDO Project based on existing software problem
reports and targeted improvements
•
Incorporate known discrepancies (DAI)
•
Incorporate IV&V findings
•
Complete high speed bus (HSB) resynchronization development
•
Developed software test bed for software testing
•
Completed most non-HSB related software changes and testing in work
–
•
Closed 23 of 26 DAIs and all IV&V findings
Demonstrated most HSB functionality and code is being debugged
–
Remaining software verification items will be closed upon completion of the next SWAT
–
Test bed will be used for in-house test prior to delivery
–
SWAT will be performed upon code update at the observatory level
•
Software update does not effect EMI/EMC operating modes and analysis
•
Software update is planned for May 15th at the observatory prior to CPT#2 and
thermal vacuum test
LWS Teams Meeting, March 2008
Page 14
HMI Observables Performance Issues
In no particular order:
•
Some scattered light in column direction, small but not well quantified.
•
MTF measurements still include Stim-Tel, data in hand, needs analysis.
•
Front window birefringence temp sensitivity, may reduce mag sensitivity
•
CCD gain stability not well measured.
•
CCD full well less than expected, but meets min requirements.
•
Uncertainty best focus setting, but small part of range.
•
Gravity release change in distortion, field flatness, etc., never tested but some
variations when rotated 90 degrees, but small.
•
Strange up-down motion in Lyot tuning motor/waveplate, requires registration
•
HSB robustness, possibly fixed – not tested.
•
Sequencer has some unexplained failures, but rare
•
Almost no solar data during testing, but some
•
Flat field not demonstrated at needed level, but close
•
Antenna induced jitter avoidance not tested, but small.
LWS Teams Meeting, March 2008
Page 15