Summary of MDI progress in 2003 to 2005 with examples of work planned for the coming few years. This page created August 2005

Notes from MDI for use in preparing senior review of SOHO operations, data processing, data analysis, and science investigations for FY06-10

I. Contents

 II. Previous Senior Reviews

The SOHO Prime Mission was from April 1996 through April 1998. The SOHO program was reviewed along with other operating missions in the NASA SEC Theme in June 1997. The result of that review was approval to continue SOHO operations and science analysis for what was called the SOHO Solar Maximum Science Program. This was followed by Senior Reviews in 2001 and 2003. The MDI submission for the proposal development, the SOHO proposal, and the final reports of the panels are linked on the following pages:

 III. MDI Science Contributions

MDI successfully provided observations leading to discoveries and progress in understanding of a number of topics during the SOHO prime mission and extended phases. MDI data has contributed to at least 21 PhD dissertations, made significant contribution to many symposia and workshops with refereed proceedings, and provided data for c. 1352 papers as of August 2005. Of the papers, there were 17, 45, 164, 117, 121, 139, 253, 210, 217, 69 for the years 1996 to 2005 respectively. (Note: Some of these may inadvertently be press stories, abstracts, etc. although I have tried to eliminate these from this count).

Some highlights of Helioseismology research based on MDI observations. (.pdf)

Some highlights of magnetic field research based on MDI observations – links to two papers. (.pdf)

 IV. Proposed Investigations

There are many science investigation topics presently proceeding with the support of MDI observations. The range of topics presently under investigation is similar to the topics in the hundreds of papers published to date. Some sample studies that require continued MDI observations in the declining and near minimum phases of the present cycle are described here.

 V. MDI Instrument Status

After nine and a half years of operation, MDI is basically working very well.

  • MDI has made about ninety million images. After on-board computations, it has delivered about fifteen million raw data images to the ground.
  • There is an expected degradation in total light throughput likely due to changes in the front window. The reduction in transmission to June 2005 was about 33% which corresponds to about 4% per year. The throughput is plotted at The jumps in early 2001, 2003 and 2004 correspond to changes in the full disk exposure time from 150ms to 165ms to 180ms and presently to 195ms.  The small jumps in 2004 and 2005 show the combined effect of operating SOHO upside down, the Doppler gradient from solar rotation, and the non-uniformity of the MDI filters.
  • In March 2000 the MDI shutter began to show a drop in exposure uniformity. The uniformity went from a part in 12000 to a part in 4000. For the 165 ms this corresponded to a jitter from one frame to the next of about 40 microseconds. The pre-launch specification was 40 microseconds. The shutter has not degraded further. In fact its performance continues to improve since we reduced the optics package temperature in February 2002. The plots at show the trends. In particular the shutter_quality.gif plot shows the uniformity. The shutter noise affects the helioseismology ONLY for degree l < 4 and adds noise to the zero level of the magnetic field. The magnetic field zero is corrected by analysis of the data (see Liu et al, 2002). If further degradation were to begin we can reduce the shutter usage with some loss of science opportunity. Since the shutter has not degraded below a part in 4000 we do not presently plan to change the observing sequence.
  • There is no detected change in the CCD flat field except for variations with focus change.
  • The drift in central wavelength of the Michelson's has nearly stopped.
  • The drift in best focus position has moved the nominal focus setting back almost to the design point. Shortly after launch it was at the limit of the adjustment range. This drift has also apparently slowed.

In summary, there is no known limit to MDI's useful life within the SOHO expected fuel life.

 VI. MDI Data Processing

For the 2 year period ending 2005.06.30, the MDI data processing system had archived 404 thousand datasets containing 19.4 Terabytes of raw and processed data. Of this 81 thousand datasets containing 3.9 Terabytes contain the calibrated level 1.5 science data and 44 thousand datasets totaling 6.8 Terabytes contain higher level science products. This data resides on 86 high-density tape cartridges. Additional copies of the level-0 data are maintained off-site.

The MDI data center has responded to 25 thousand individual online requests for data amounting to about 25 Terabytes. Data exports in the two years ending 2005.06.30 included 9600 requests totaling 6.2 Terabytes. Most requests are for multiple datasets. Requests for MDI data processed through the SOHO archives at GSFC and the remote SOHO archives in Europe are not shown here. Data export requests plots are shown at

 VII. MDI Publication Record

For the list of 21 known Dissertations see: Dissertation List (Wachter makes 22)

JOSO - Joint Organization for Solar Observations – Prize:  Laurent Gizon was awarded the first JOSO Roth Saubermacher Prize for an outstanding paper by a young scientist.  Dr. Gizon’s work is in local helioseismology with MDI data.  His dissertation is in the list above.

For list of Proceedings see: Conference Proceedings List

For list of Papers see: Paper List

 VIII. MDI Education and Public Outreach Activities

Education and Public Outreach are important adjunct activities of the MDI team. These activities include:

·      Press Release – MDI Co-Is at LMSAL presented a press release concerning the coupling of evolving magnetic fields in the corona.  Both TRACE and MDI data are used in this study. This report extends prior understanding of the connection between field changes in the photosphere and the types of dynamics in the corona.  This understanding will help the development of flare prediction techniques.

·      July 2004 National Geographic – MDI images and consultation were used in the July 2004 story on “Hot News From Our Stormy Star

·      Press use of MDI images - The press used MDI images and interviews with MDI scientists on a number of occasions including the 2003 transit of Mercury and the October-November 2003 active regions and flares.  The daily farside images are often highlighted in stories in

  • Space Weather Monitors -- In conjunction with NSF, the Stanford Solar Center has developed low-cost (~$150) space weather instruments that monitor and track changes to the Earth’s ionosphere caused by solar activity.  The monitors were designed and developed by teacher interns over a 2-year period and have been beta-tested in local minority-serving high schools. 100 monitors, funded by MDI, are currently in production, to be distributed to high school and community colleges throughout the nation.  The hope is to provide experience with hands-on science and generate enthusiasm for science and technology amongst young people, with a key target being students from under-represented groups.

The International Heliophysical Year (IHY), 2007, Organizing Committee and the United Nations have designated our Space Weather Monitors as supported projects of the IHY.  The hope is to place 5 of these low-cost monitors in each of the 191 nations of the (UN-designated) world.  Funding is being sought from private foundations.

  • Our poster-spectroscopes, previously developed with MDI funding, continue to be extremely popular.  During the last 2 years we have redesigned and reprinted the instrument to be distributed in a flat format (instead of rolled up poster), 11”x17” size, and perforated for punch-out.   This saves about 20 minutes of cutting and the instrument can now be assembled by a student in less than 15 minutes.  Class-size packets of spectroscopes are provided to teachers through the nation.  To date, we have distributed roughly 40,000 spectroscopes.
  • Teacher Workshops -- One of our scientists, John Beck, has been working very closely with Lawrence Livermore Laboratory’s Fusion-Astro Research Academy and the Edward Teller Education Center to develop and present workshops for teachers throughout the state.  Spectroscopy is a key topic for these workshops, and John has taught middle and high school science teachers how to make and use our foldable spectroscopes.
  • Participation in Earth& Sky SECEF workshop – MDI team members participated in a workshop hosted by the SECEF and designed for National Park Rangers.  We provided information and activities relating to the Sun and how information on the Sun could be provided to the public through the national parks.  One of our activities, a model of the Sun’s path during the solstices and equinoxes, was particularly well-received and ended up being used in the field and highly praised by one of the ranges.
  • Student Workshops – MDI team members continue to give a collection of workshops to local elementary, middle, and high school students.  New additions in the last 2 years include Science Nights for elementary schools, Take Your Sons & Daughters to Work spectroscope workshops, SUCCESS Summer Camp workshops for under-served middle school girls, Reach for Tomorrow workshops for underserved students nationwide, short activity workshops for Community Day at Stanford, as well as the occasional teacher-requested spectroscope workshop for local schools.  During the last year we expanded our repertoire by adding planetarium programs using a portable StarLab planetarium.  In conjunction with the Lawrence Hall of Science, we are currently developing a solar-science based program designed for use in small, interactive planetaria.
  • Solar Center Website – We have continued development and maintenance of our public information web site at  To coordinate with NASA’s educational theme of “Ancient Observatories – Timeless Knowledge,” we developed a section on Native American Medicine Wheels, which was highlighted and linked into NASA’s primary AO website.  The Solar Center website now also includes an extensive section on the Space Weather Monitor project mentioned above. We also had a new logo designed and upgraded the “look” of the website.
  • Distribution of informative and educational posters -- We continue to distribute a collection of Sun-related posters and informational material, as well as the spectroscopes. Most of the requests are generated by our website, but we also distribute the materials at public events such as "Sun-Earth Day" museum exhibits.  During the last 2 years we estimate to have distributed about 10,000 posters, 75% of which were spectroscopes.