Transcript SDO at the Space Weather Workshop, April 2007

Solar Dynamics
Observatory
W. Dean Pesnell
NASA, Goddard Space Flight Center
SDO Project Scientist
Space Weather Workshop, April 2008
There lands the Fiend, a spot like which perhaps, Astronomer in the Sun's lucent Orbe
through his glaz'd Optic Tube yet never saw.
John Milton, Paradise Lost, 1674, Book 3, Line 590.
Space Weather Workshop, April 2008
Solar Dynamics
Observatory
The Solar Dynamics Observatory (SDO) is
the first Living With a Star mission. It will
use telescopes to study the Sun’s magnetic
field, the interior of the Sun, and changes in
solar activity. Some of the telescopes will
take pictures of the Sun, others will view the
Sun as if it were a star.
•The primary goal of the SDO mission is to
understand, driving towards a predictive capability, the
solar variations that influence life on Earth and
humanity’s technological systems by determining:
–How the Sun’s magnetic field is generated and structured
–How this stored magnetic energy is converted and released
into the heliosphere and geospace in the form of solar wind,
energetic particles, and variations in the solar irradiance.
Space Weather Workshop, April 2008
Progress in Past Year
• Instruments delivered and installed
• Observatory assembled
• Environmental testing has begun
– EMI/EMC complete
– Vibe/acoustics this week and next
– Thermal vacuum starts in June
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Ground system running at full mission data rate
Launch December 2008
Sun has not started the climb to Solar Cycle 24
No major issues or problems!
Space Weather Workshop, April 2008
SDO: NASA/LWS
Cornerstone Solar Mission
• NASA and three Instrument Teams are building SDO
– NASA/ Goddard Space Flight Center: build spacecraft,
integrate the instruments, provide launch and mission
operations
– Lockheed Martin & Stanford University: AIA & HMI
– LASP/University of Colorado & USC: EVE
• Launch is planned for December 2008 on an Atlas V
EELV from SLC 41 at Cape Canaveral
• SDO will be placed into an inclined geosynchronous
orbit ~36,000 km (21,000 mi) over New Mexico for a
5-year mission
• Data downlink rate is 150 Mbps, 24 hours/day, 7
days/week (watching 380 movies each day)
Space Weather Workshop, April 2008
Atlas V carries Rainbow 1 into
orbit, July 2003.
Why So Much Data?
A goal of LWS is to predict Space Weather (SWx). Why is there
so much data from SDO and how can it be used to make those
forecasts, today, next year, and the next solar cycle?
The data returned by SDO was designed to have:
Simultaneity: Full-disk images at many wavelengths every 1.25
seconds to resolve the time dependence of the flaring regions at
different temperatures
Coincidence: Full-disk EUV images to see the entire face of the
Sun in each image, important for complete coverage and non-local
effects; full-disk magnetograms to track the magnetic field
Resolution: 1.7” images at a 10 second cadence
Long-term: Cover an appreciable part of the solar cycle
Space Weather Workshop, April 2008
Why So Much Data?
A betting matter in the
19th century was
whether a galloping
horse ever had all four
hooves off the ground
at the same time.
Le derby d'Epsom, by Théodore Géricault, 1821
This picture shows the view that the hooves were off the
ground in a leaping motion.
Space Weather Workshop, April 2008
Eadweard J. Muybridge
was a pioneering
photographer who
investigated this
question. His patron
was the founder of
Stanford University.
Why So Much Data?
Muybridge knew that the stride of a
galloping horse was too long for a
single camera and used 16 cameras to
emulate a moving frame of reference.
Le derby d'Epsom, by Théodore Géricault, 1821
Muybridge needed data that
showed all of the hooves at the
same time (coincidence) but
simultaneity in colors was not
important. It was essential to
resolve the motion.
He also knew that multiple cameras
were necessary because the film could
not be advanced quickly enough.
The shutter speed was fast enough
and the shutters were tripped by
electrical signals triggered by the
horse’s hooves.
Space Weather Workshop, April 2008
Why So Much Data?
The animated version of Muybridge’s images can be found at
http://en.wikipedia.org/wiki/Image:Muybridge_race_horse_animated.gif
Space Weather Workshop, April 2008
Trace image of a
filament eruption
from AR 10944 on
March 3, 2007.
Even this late in
the solar cycle the
fields are complex.
Movie available at:
http://trace.lmsal.com/POD/movies/T171_20070302_04_filadest.mov
Still need the fulldisk temperature
maps to
understand these
motions. Unlike a
horse’s gait each
active region is
different!
What will we learn
from the magnetic
field
measurements?
Space Weather Workshop, April 2008
The SDO Spacecraft
EVE (looking at CCD radiator
and front)
AIA (1 of 4 telescopes)
The total mass of the spacecraft at
launch is 3200 kg (payload 270 kg;
fuel 1400 kg).
Its overall length along the sunpointing axis is 4.5 m, and each
side is 2.22 m.
The span of the extended solar
panels is 6.25 m.
High-gain antennas
Solar arrays
Total available power is 1450 W
from 6.5 m2 of solar arrays
(efficiency of 16%).
The high-gain antennas rotate
once each orbit to follow the Earth.
HMI (looking down from top)
Space Weather Workshop, April 2008
SDO Operations
•
Mission Operations Center for SDO is at NASA's
Goddard Space Flight Center in Greenbelt, MD.
– Maintain its inclined geosynchronous orbit
– Keep SDO pointing at the Sun
– Keep the data flowing.
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Communications with the spacecraft are via two
radio dishes at NASA's site in the White Sands
Missile Range in New Mexico.
Science teams plan operations of the instruments
with MOC and analyze the data.
Operations Philosophy
MOC in Building 14
– Few modes: turn it on and let the data flow!
– Images are sent to the ground for processing
– Data is made available soon after downlink; people
can use the data in near-real-time
– Campaigns and collaborations are coordinated
when convenient, but the data is always available
18 m antenna assembly
Space Weather Workshop, April 2008
SDO Operations
• SDO will produce an enormous
amount of data
– 1.5 Terabytes each day
– Almost 0.75 petabytes each year
• DDS acts as observatory tape
recorder
• Data is forwarded to SOCs, who
archive and serve the data
• Two copies exist at all times after data
is on the ground
• Data flow is similar to watching 380
movies every day
– Some channels are actually measured
more frequently
– 500,000 iTunes downloads each day
Space Weather Workshop, April 2008
Data Distribution System being test
in Building 14 (60 TB raid storage)
Space Weather Data
Instrument
Description of Space Weather Data Product
EVE
1-minute, 1-nm spectral irradiance for MEGS-A
1-minute, 1-nm spectral irradiance for MEGS-B
10-sec averaged ESP and MEGS-P bandpasses
10-sec flare location from ESP quad diode and SAM
10-sec emission lines (TBD), 15 min latency
AIA
Quick-look intensity images, 1024 x 1024 pixels, 8
wavebands, 10 sec cadence, 15 min latency
HMI
Quick-look longitudinal magnetograms and continuum images,
50 sec cadence, 15 min latency
A summary of SDO SWx data. Data will be placed at a site
accessible via the Internet. Your cadence may be different.
Space Weather Workshop, April 2008
HMI Space Weather Plans
• Near realtime (< 15 min delay) SWx data
– 4k x 4k magnetogram
–LOS with 50 sec. cadence, vector every 10 min.
–Magnetic indices are being developed and need to be assessed by the
SWx community
– Continuum images
• Helioseismic data products
– Far-side images
• Models of the convection zone and dynamo
– Active region emergence and evolution
– Magnetic field creation and emergence
– Enables the prediction of long-term solar activity
• Available from the JSOC as a pull product
AIA Space Weather Plans
• Near realtime (< 15 min delay) SWx data
– Irradiance-calibrated images in 9 UV/EUV/X-ray wavelengths
– EVE provides irradiance calibration of images
– Quicklook data (1kx1k images, movies at each wavelength covering past
hour & day.)
• Image analysis to improve near-term predictions of flares and other solar
activity
– Temperature proxies to provide better flare predictions?
– Locations of coronal holes, the sources of high-speed streams
• Models of the coronal magnetic field, predictions of the solar wind
• Available from the AIA web site or the JSOC as a pull product
EVE Space Weather Plans
• Provide near realtime (< 15 min delay) SWx data:
– High resolution spectra (as counts or “crudely” calibrated) (MEGS)
• 10 second cadence
– Broadband solar irradiances (ESP and MEGS-P)
• More rapid (4 Hz) cadence
– First-ever near-realtime XUV and EUV flare monitor
• SWx data to be used by:
– Ionospheric disturbance nowcasting (XUV/EUV flare response)
– Operational GAIM (Global Assimilative Ionospheric Model)
– Operational SOLAR2000 (solar irradiance model), which is in-turn used
as a driver for operational atmospheric, ionospheric, and neutral
thermospheric wind models
• SWx data will be available as a pull product from EVE web site
– May also be served through NOAA-SEC
SDO Construction
SDO almost complete in Building 7 at
GSFC. View of AIA side.
View of SDO with HMI and EVE.
Space Weather Workshop, April 2008
SDO Construction
Space Weather Workshop, April 2008
SDO Construction
Space Weather Workshop, April 2008
Summary
1. The Sun’s magnetic field is the source of almost all SWx. As
the Sun waxes and wanes with the solar cycle we must
monitor its ability to affect spacecraft and society.
2. Our modern world requires knowledge of The Sun Today.
3. Global and local data are needed to provide this knowledge.
Measure global data, Observe the Database for local data.
4. SDO will measure the Sun’s light output and magnetic field,
making Ultrasounds of the Sun and allowing us to model the
Plasma Environment of the Lower Corona.
5. SDO will allow us to predict when the Sun will affect
spacecraft and society.
Space Weather Workshop, April 2008
Contact Information
• W. Dean Pesnell: [email protected]
• http://sdo.gsfc.nasa.gov soon to be http://www.nasa.gov/sdo
Space Weather Workshop, April 2008