SOI-MDI Newsletter

Number 4: February 1994

IN THIS ISSUE:

• MDI is Delivered to Europe (and comes back again)!

• May Team Meeting

• October Team Meeting

• The PI Speaks

• SOI-MDI Science Support Center

• Team Science Working Groups

• 2nd SOHO Workshop

• Team Science Plans

• New Arrivals

Calendar

1994

• April 28 - Redelivery of MDI to MMS-UK.

• May 15-20 - SOI-MDI Team Meeting, Los Angeles.

• May 16-20 - GONG Meeting, Los Angeles.

• June 15-17 - SWT at ESTEC

• October 9-12 - SOI-MDI Team Meeting, Fallen Leaf Lake.

Delivery and Return

On Sunday, January 16, at 1:45 pm Pacific Standard time, United flight 930 took off from San Francisco, carrying the MDI instrument in its cargo bay and three ``MDIers'' (Rock Bush, Tom Pope, and Dave Akin) in the passenger cabin. [Comment by Jake Wolfson at the time: "MDI is higher than it's been, but not as high as it will get."]

Here's Jake's report:

The flight model MDI was put onto an airplane on 16 January, arrived in England the next morning, and was safely into the MMS-UK facility by the afternoon of the 17th. Tom Pope, Dave Akin, and Rock Bush went with the instrument. Jake Wolfson joined the team a day later. The instrument and GSE were unpacked and set up and a thorough bench test was conducted. All systems operated nominally including the relay which had failed during the workmanship vibration test of the EP and then began working after the board was removed from the box for examination. The bench test included stimulating the instrument with the stimulus telescope in modes where it projected a target, a jittering target, and a laser beam. The instrument was then mechanically integrated to the spacecraft payload module (PLM) and a trial fit of the MLI was accomplished. All went well, although the interbox cables need some additional strain relief and three of the holes in the PLM need some attention as the bolts tend to bind when being inserted into them. Electrical integration was then accomplished. A few items that need follow- up were noted but basically all went well and MDI powered up properly, received commands properly, and output telemetry properly.

Functional testing then commenced. This involves controlling the instrument with the S/C GSE rather than the MDI GSE and thus required considerable software debugging. Unfortunately very little preparatory work on the command files had been performed by MMS-UK personnel before we arrived so it had to be done in real time. In addition some significant changes had been made to their operational software since the integration of the EM a year earlier and this meant stepping back quite a ways in the learning curve. Eventually more and more of them worked and when our allocated test time had expired most were in good shape; although very little of the Special Performance Tests (SPT) had been run. The most serious problem that was encountered was missing block in the high rate telemetry; and maybe in the low rate telemetry as well. Efforts to solve this problem made progress in terms of both understanding the problem better and in the volume of missing data, but were not successful. It appears that the data is being lost between the S/C GSE and the MDI GSE, but this has not been proven.

The instrument was deintegrated on 9 February, packed on the 10th, and returned to LPARL on Friday, the 11th. Redelivery to MMS-UK is scheduled for April 28th.

While the instrument was in England the efforts at LPARL concentrated on analyzing the data that has been collected over the last half year and attacking the problems which resulted in the need to bring the instrument back to Palo Alto - simplistically labeled the gradient, ice, and relays.

Analysis of various pieces of the calibration data, supported by some new measurements, have begun to give us a handle on the ``gradient'' anomaly. The new measurements involved measuring flight spare beam- splitters using the Stanford spectrograph as well as equipment at LPARL. A variation of intensity with the angle of the incident beam is observed which may well account for the linear portion of the overall gradient.

It was decided to add an 8 level heater control capability to the CCD, which already has a single level for warm outgassing, in order to be able to operate at tempera- tures where the ``ice'' is not a problem should it occur in orbit but still as cold as acceptable. The design for this system was completed, the parts were either located in stores or ordered, and conversion of the design to a printed wiring board was initiated. In parallel, the assembling of a new CCD camera head was initiated with special attention being paid to cleanliness and to measuring whether ``ice'' forms at steps during the assembly process.

The direction of attack in the relay problem area was to continue to gather information, as well as to locate and procure some spare relays. Two of the mass model SM boards were modified to accept one each of the type of relays that are of a concern and the full assembly was vibrated in a configuration that enabled measuring the vibration levels at the board as well as at the box and also enabled measuring what voltage was required to flip the relay after each, ever increasing, vibration level. A report on the results is in process.

MAY TEAM MEETING

The Next Team Meeting is May 15-17-19-20 in Los Angeles

The next SOI-MDI Team Meeting will be spread out over the week of the GONG meeting, May 15-20, in Los Angeles. The first session will take place in the conference room at the Holiday Inn Crown Plaza, beginning at 3 p.m. on Sunday, May 15. Team science working group meetings will be held at the University of Southern California following the GONG poster sessions on Tuesday 17 May and Thursday 19 May. A wrap-up meeting will take place on Friday afternoon, after the final GONG session.

A more detailed agenda will be mailed out in mid-April.

For information about housing at USC, and about plans for the GONG meeting, please contact Ed Rhodes, erhodes@solar.stanford.edu, 213-740-6329.

For further information about the Team Meeting, contact Margie Stehle, mstehle@solar.stanford.edu, 415- 723-1505.

Proposed SOI-MDI Meeting Agenda

Sunday 15 May, 3 - 5 pm - Holiday Inn Crown Plaza:

Team Science Working Group Meetings

Tuesday 17 May, pm - USC Conference Center:

Team Science Working Group Meetings

Thursday 19 May, pm - USC Conference Center:

Team Science Working Group Meetings

Friday 20 May, 1-3pm - Team Meeting Wrapup

OCTOBER TEAM MEETING

Fallen Leaf Lake in October!

Yes, it's true! By popular demand, we will return to the beautiful Sierra for the 1994 Fall Team Meeting. Don't miss it! Mark your calendars now: October 9-12, 1994!!

The above announcement has appeared in the last couple of issues of SOI-MDI News. Now it's time to do more than mark your calendars: we need to know how many people to expect, because the Sierra Camp wants a guaranteed number from us in a few weeks. Included with this newsletter is a separate (RED) page for you to use to let us know your plans. Please fill it out and return it as quickly as possible. The same information will also be accepted via e-mail to mstehle@solar.

All SOI-MDI team members are invited to the meeting, and Co-Investigators are expected to attend. Spouses/ guests may attend at a reduced rate (still to be determined).

The meeting will run from dinner time on Sunday, October 9, through lunch on Wednesday, October 12. The first session will be held on Sunday evening. The format will be very similar to our 1990 meeting at Fallen Leaf, with free time allowed around the scientific sessions for those who wish to hike, row, sail, swim (!), play tennis, or just relax.

The registration fee will include all meals and lodging, and will probably be around $400. Unfortunately, it is not possible to add extra days to your stay at the Camp, but there are plenty of accomodations in South Lake Tahoe if travel arrangements necessitate a longer stay. The Camp will provide transportation from the South Lake Tahoe airport or from the bus terminal in the city of South Lake Tahoe if you are flying into Reno.

More information will be forthcoming in a few months, but in the meantime, please take a few minutes to fill in the blanks and mail the form!

From the Project Office

Phil Scherrer, Stanford

At the October team meeting, I announced an SOI team meeting would be held on the day before the start of the spring GONG conference in LA. After discussions with some of you, and in particular with Roger Ulrich and Ed Rhodes, we have now concluded that that meeting should be mostly distributed throughout the week. Our plan is to have one or two of the Team Science Working Groups (see below) on Sunday late afternoon and to have 3 or 4 other working group 1-hour discussions on two occasions (as parallel activities) during the week. We will then get together as a full team just after the close of the conference on Friday afternoon, from 1 to 3 PM at the hotel. The hotel needs to prepare the room for an evening event so we must be done by 3. I believe the Friday travel impact will be small. We will take any feedback into account in choosing which working groups will meet on Sunday.

SOI Team Science Analysis Progress

At the 1993 Spring and Fall SOI Team Meetings we discussed methods for accomplishing the SOI principal science objectives in a coordinated manner. As a result of those discussions we have implemented a set of working teams each with specific goals to implement the processing required to accomplish particular science objectives. We have organized the working groups with three named individuals with different responsibilities:

• Local Coordinator: has the responsibility to get the science analysis accomplished, i.e. the one who make sure the job gets done.

• Team Leader: has the responsibility to help the Local Coordinator to bring in the team's knowledge and experience to attack the problem, i.e. the one who will make sure the science gets done right.

• Responsible Programmer: has the responsi bility to work with the Local Coordinator to get the required programs implemented and verified, i.e. the one who does or helps do the work.

After the last team meeting, in October 1993, several of us met and listed some of these objectives and people we believed might wish to participate on the working groups. Shortly after that, we had a meeting of the potential Local Coordinators to begin working out the actual operation of the groups. We have now identified the initial set of objectives and have identified Local Coordinators for those working groups. Prior to this newsletter, not all of the Local Coordinators have announced themselves to the full SOI team or to the strawman list of interested working group participants.

Elsewhere in this newsletter are summaries of each objective and the working groups as established to date. These summaries contain a terse description of the objective, the identified key individuals, and the strawman (or better) list of group members. Please review this list and attach or detach yourself as you feel is appropriate. The key requirement to remember is that these are to be WORKING groups. If your name is to be on one of these lists you are making a commitment to do work. If you do not wish to make such a commitment at this time, please so inform the Local Coordinator. If you wish to make such a commitment and your name is not on a list, please contact the Local Coordinator.

Note that many of the Team Leaders have not been listed. It is one of the responsibilities of the Local Coordinator (LC) to work with the team to decide who will be the Team Leader (TL) for that Team Science Working Group (TSWG). If you think or know you are the logical TL for a TSWG please tell the LC ASAP.

As part of his role as ``SOI Data Scientist,'' Rick Bogart needs to have some of the output from the TSWGs. Therefore he is taking the lead in coordinating the formation and early work of these groups. Please see him or me if you have comments about the general scheme. There is also more information about the TSWGs in his note in this newsletter.

For more info about the Working Groups, see below.

SOI-MDI Science Support Center

Jim Aloise, Stanford

The SOI-TN-109 ``SSSC Implementation Version 1.0'' presents the state of the SOI-MDI Science Support Center as of November 1993. Since then various restrictions have been removed and new features have been implemented. The advances of note and our current efforts are discussed here.

The lago_svc, which supplies a client/server model for functioning of the Lago Data Wheel 8mm tape mass storage, has been upgraded to act in an asynchronous manner whereby a client may proceed after a request and later be informed of the completion of the request. With this async behavior the lago_svc can now simultaneously operate both of the internal Lago tape drives. The Lago archiving program (lagoarc) was updated to take advantage of this new lago_svc.

The Pipeline Execution program (pe) will now wait for data to be retrieved from the Lago Data Wheel when pe requests the data from the database server (dsds_svc) and the data is not on-line. The dsds_svc was upgraded to inform pe that the data is not on-line and then initiate interaction with the lago_svc to retrieve the data from tape. Dsds_svc will assign disk storage for the data to be read into and request services from the lago_svc to read the required tape and file into the storage. When the data is back on- line, dsds_svc informs pe which may now continue its processing. The data remains on-line until its storage is needed elsewise by dsds_svc.

There is currently a restriction to the automatic data retrieval from tape, in that, the tape must already be in the Data Wheel. Work is now proceeding on a Lago User Interface (lui) which will present ongoing Data Wheel status and notify and allow an operator to stage tapes as required.

The evaluation of the Oracle Version 7 is complete. We have abandoned the V6 and all our relevant software now runs under V7.

Two new strategy level modules of note are ingest_svc and cvtlm_svc. The telemetry ingestion server is the first point of entrance for data into the system. It will take in telemetry data, as currently recorded by the Electrical Ground Support Equipment (EGSE), and place it on-line within DSDS managed storage and catalog it in the database. The convert telemetry server can then access this data within a normal pipeline. Cvtlm_svc will extract the image data from the telemetry stream and catalog information on each image with the database via dsds_svc. A catalog entry is also made for a dataset that consists of these images. This is done in the normal manner by pe when a strategy level server completes. Currently the name of the cvtlm_svc output dataset is given in the map file that defines the pe processing. Work is now underway to have cvtlm_svc determine the dataset name from the actual telemetry data and inform pe of what it has found. Work is also underway to better define the telemetry frame headers and create more realistic data streams to further develop the cvtlm_svc processing and define how datasets will be recognized and sorted.

With the advent of ingest_svc and cvtlm_svc we now run a complete pipeline from ingestion of the telemetry data through to creation of velocity l-nu diagrams.

We are about to place all of our development under a Configuration Management (CM) system. The CM is based on BCS (A Baseline Configuration System) and RCS (Revision Control System). BCS is a set of utilities for maintaining a single baseline and multiple staging areas for a software development effort. BCS provides configuration management functionality as well as the means for multiple users to work concurrently on a common source tree with mininal conflict. RCS is a widely used version control system.

We will soon begin a review of all of our error handling. Now that we have a broader picture of how things should work we can better define what is reasonable to do in the face of various errors. It may be that we need some rollback capabilities beyond those supplied by the database.

We plan to continue our throughput studies and understand the tradeoffs with multiple platforms, NFS or local disk and tape I/O, coax or fiber optics links. Various timing runs have been done and a preliminary study completed. This will be extended.

Team Science Working Groups

Rick Bogart, Stanford

Stanford and Lockheed scientists and programmers got together in November and December to organize the development of the team science analysis data processing efforts. We are implementing the organizational structure outlined at the October team meeting for team science analysis. Each team science working group has a Team Leader, a Local Coordinator, and a Responsible Programmer. Each science team is responsible for describing and setting the priorities of scientific objectives and for establishing appropriate requirements and constraints on observations and analysis. The team should communicate these objectives and requirements through its Team Leader or directly to the Local Coordinator. The Local Coordinator, who should be a member of the Stanford/Lockheed scientific community, is the person with overall responsibility for designing and achieving the observations and data processing required for scientific analysis. The Team Leader is expected to convene working group meetings and to oversee final analysis and publication. Implementation of the observing and data processing procedures will be overseen by a Responsible Programmer at the SOI Science Support Center, working closely with the Local Coordinator, and in conjunction with other members of the Center staff as appropriate.

The Local Coordinators are currently in the process of organizing the teams (including identifying Team Leaders in most cases) and establishing development plans. The Active Region Seismology team has already held a working meeting to define three campaign observing programs. We expect several of the teams to hold splinter group meetings during the May Helioseismology conference in Los Angeles. Anyone interested in participating who has not yet been contacted should get in touch with either the relevant Team Leader or Local Coordinator.

Following is a list of the science analysis teams that have been set up. The Team Leader (where selected), Local Coordinator, and Responsible Programmer are listed in that order.

• Internal Rotation (2-D inversions):

  	J. Schou	J. Schou	K. Leibrand
  
  

• Synoptic Magnetic Fields:

  	T. Hoeksema	T. Hoeksema	K. Scott
  
  

• Surface Flows & Structures (correlation tracking):

  	---		N. Hurlburt	M. Morrison
  
  

• Summary Data (for SOHO correlative studies):

  	---		R. Bush		J. Suryanarayanan
  
  

• Ring Diagram Analysis for Convective Structures:

  	---		P. Milford	L. Bacon
  
  

• Coronal Synoptic Field:

  	T. Hoeksema	X. Zhao		K. Scott
  
  

• GOLF Intercomparison:

  	R. Ulrich	R. Bogart	J. Aloise
  
  

• VIRGO Intercomparison:

  	---		T. Hoeksema	J. Aloise
  
  

• Limb Figure Analysis:

  	---		P. Milford	L. Sá
  
  

• Active Region Seismology:

  	E. Zweibel	T. Tarbell	---
  
  

• Time-of-Flight Analysis for Convective Structures:

  	---		A. Title	--- 
  
  

Welcome, Mons!

Lockheed employee Mons Morrison began working directly for Stanford in January, on aspects of the science data analysis for SOI. He shares an office with Jesper Schou in the ``Boxtop.''

At Lockheed, Mons was a key individual in the production of the software for the SXT (on YOHKOH) analysis environment which is now in use by institutions world wide.

2nd SOHO Workshop on MASS SUPPLY and FLOW in the SOLAR CORONA

Isola d'Elba, 27 September - 1 October 1993

by Todd Hoeksema, Stanford

This conference had 4 themes - Streamers, Coronal Holes and Solar Wind, Loops and Prominences, and Small Scale Structures, though the topics tended to blend a little. Each subject was assigned a day and the day consisted of 3 reviews, a handful of contributed oral papers, a number of posters, and a Working Group Session. Each poster author was given time for a 2- minute summary during the working group sessions. A summary of the sessions was presented by the working group leaders on the final day. There were about 100 scientists present, including representatives from each of the non-helioseismology SOHO instrument teams. The schedule on the first day was a little confused because a 24-hour rail strike on Sunday delayed the arrival of several participants.

The conference opened with a brief status report by Vicente Domingo, who gave a nice overview of the scientific capabilities of the mission and described the scheme for ground operations. On the second day Roger Bonnet talked about SOHO and the future of space solar physics. He was amazed (and maybe even a little dismayed) at how BIG the SOHO spacecraft is.

Day 1: Streamers - Roger Kopp, Group leader.

Reviews were presented by G. Schulz on Coronal Streamer Theories and by G. Poletto on the role SOHO will play. There was no review of observations. There were talks on the recent Spartan-201 results among others. Some of the highlights included the observations of structures at magnetic cusp points. The cusps can be either dark or bright, dark suggesting open field lines and bright associated with reconnection. In either case density is primary cause of the observed structure. Another interesting observation is that streamer temperatures are generally high and are fairly constant over a large altitude range - out to 3.5 Rs. It was noted that models must strive to explain the ion and electron temperatures and use more complete energy equations.

Day 2: Coronal Holes and Solar Wind - E. Marsch and R. Schwenn, Group leaders

Day 3: Loops and Prominences - E. Priest, Group leader

Day 4: Small Scale Structures - O. Kjeldseth- Moe, Group leader

Day 5: Continued discussions and a tour, Nina, Group Leader.

3rd SOHO Workshop

25-30 September 1994 - Estes Park, Colorado

The Scientific Organizing Committee intends to blend theory and observation in the sessions. The goals are to stimulate the optimal SOHO observations and promote the essential coordination with other observations so that the scientific problems will be attacked most effectively.

ABSTRACTS MUST BE RECEIVED BY THE LOC CHAIR NO LATER THAN 30 APRIL 1994.

For further information, contact Pamela Bergstedt, NOAA/ERL/SEL-R/E/SE-2, 325 Broadway, Boulder, CO 80303; phone 303-497-3113, fax 303-497-3645; e-mail pbergstedt@selvax.sel.bldrdoc.gov.

Team Science Plans

TEAM SCIENCE OBJECTIVE: INTERNAL ROTATION

Team Leader:		J. Schou
Local Coordinator:	J. Schou
Responsible Programmer: K. Leibrand

Technical Summary:

Schedule:

• Class A (near term)

Outstanding Problems:

• Need to either fix problem for the favored algorithm or use some other algorithm for high frequency modes.

• Need to decide whether we need/want/can get individual mode frequencies or whether a- coefficients are just as good or better.

• Lots of minor problems need fixing.

• Inversion algorithms are still being worked on.

Active / Knowledgeable Team Members:

E. Anderson		 F. Hill		J. Schou         

T. Brown		 S. Jefferies		T. Sekii        

J. Christensen-Dalsgaard S. Korzennik		P. Stark         

W. Dziembowski		 A. Kosovichev		M. Thompson        

C. Genovese		 K. Libbrecht		J. Toomre         

P. Goode		 P. Milford		P. Wilson         

D. Gough		 E. Rhodes         

Comparable Projects / Datasets:

• GONG

• Mt Wilson 60'

• Fourier Tach

• Big Bear

• NSO South Pole

Detailed description of the goals and analysis procedures:

Time-series analysis: The input spherical harmonic time-series are generated in a previous part of the pipeline. While the time-series analysis method should be taken into account when generating the time-series, this is generally not done.

The first part of the analysis consists of rejecting bad data points and filling the gaps in the time-series. As we do not expect substantial gaps or many bad data points, this should not be a serious problem.

The second part consists of Fourier transforming the time-series and, depending on the method used in the next step, construct power spectra. As Fourier transforms are only efficient on series where the length is a product of small primes some padding will have to be performed. On the other hand I would strongly argue against only using lengths of 2N. Given the speed of FFT algorithms, I would suggest that the Fourier transforms are generated when needed and not stored.

The third part, which is where the problems are, is the analysis of the Fourier transforms or power spectra. I think it has been generally accepted that the statistical properties of the data must be taken into account to a larger extent than has previously been done. This leaves two methods that have been implemented:

1. The algorithm being developed by Ed Anderson at NSO for the GONG project. This method uses power spectra and attempts to fit individual mode frequencies.

2. The method I developed for analysing Fourier Tachometer data at HAO. In this method all m's at a given (n,l) are fitted simultaneously, currently using a- coefficients.

At high frequencies method 2 is very slow unless the errors are allowed to be very large. The cause of this problem is known and believed to be fixable. Method 1 seems to have a number of systematic problems, but they are likely to be solvable.

I currently have method 2 running here. For obvious reasons I suggest that we work on this method keeping an eye on what GONG decides to do. The program could need a major overhaul and the high frequency problem should be looked into. Also we should perhaps implement the algorithm in a Politically Correct language. Both of the tasks should be doable on a fairly short timescale. This part of the analysis is likely to be rather computationally intensive.

Finally the results have to be looked at to remove bad points and maybe iterate the procedure.

The time-series analysis should be part of the pipeline. Also note that the various mode parameters also form the basis of the radial stratification problem and the asphericity problem.

Inversions: Here I would suggest that we use 2- dimensional inversions like the ones developed by JCD, MJT and myself. I have a working code running here. Some development still needs to be done, but probably not by a programmer here.

TEAM SCIENCE OBJECTIVE: SURFACE FLOWS AND STRUCTURES (Correlation Tracking)

Team Leader:

Local Coordinator:	N. Hurlburt

Responsible Programmer: M. Morrison

Technical Summary:

Schedule:

• Class A (near term)

Outstanding Problems:

Active / Knowledgeable Team Members:

R. Bogart 	P. Milford 	G. Simon 


D. Hathaway 	P. Scherrer 	T. Tarbell 


N. Hurlburt 	R. Shine 	A. Title

Comparable Projects / Datasets:

• SOUP

• La Palma

TEAM SCIENCE OBJECTIVE: SUMMARY DATA

Team Leader: 


Local Coordinator:	R. Bush


Responsible Programmer:	J. Suryanarayanan

Technical Summary:

Schedule:

• Class A (near term)

Outstanding Problems:

• Need to define useful data set.

Active / Knowledgeable Team Members:

R. Bush 	A. Poland 	


V. Domingo 	X. Zhao


T. Hoeksema 

Comparable Projects / Datasets:

• WSO

• Mt Wilson 150'

• KPNO VT

TEAM SCIENCE OBJECTIVE: RING DIAGRAM ANALYSIS FOR CONVECTIVE STRUCTURES

Team Leader:

Local Coordinator:	P. Milford


Responsible Programmer:	L. Bacon

Technical Summary:

Schedule:

• Class B (medium term)

Outstanding Problems:

• Current techniques are inefficient.

Active / Knowledgeable Team Members:

K. Bachmann	P. Milford


D. Gough	J. Toomre


F. Hill

Comparable Projects / Datasets:

• NSO HRST (?)

• Fourier Tach

TEAM SCIENCE OBJECTIVE: CORONAL SYNOPTIC FIELD

Team Leader:		J. T. Hoeksema


Local Coordinator: 	X. P. Zhao


Responsible Programmer:	K. Scott

Technical Summary:

The other approach is to mimic the effect of the solar wind through a purely static solution to the MHD equations. This approach has been used to extrapolate the observed synoptic magnetic field in the photosphere into the corona. Distortion of the coronal magnetic field by the solar wind requires the presence of both volume currents and sheet currents in the corona and heliosphere, so that the hydrodynamic and magnetic forces are coupled. The potential field source surface model mimicing the effect of the heliospheric volume currents on the coronal field has been successfully used to calculate the position of the zero radial component of the large-scale coronal magnetic field and thus predict the location of the heliospheric current sheet (Hoeksema et al., 1982, 1983) and the location of coronal holes (Levine, 1977). In order to predict the coronal magnetic field strength and plasma properties as well as field polarity, and to improve the prediction of the flux tube expansion factor and the solar wind speed, it is necessary to develop a model which includes the effects of both volume and sheet currents. In addition, as the boundary condition of the problem, the photospheric field must be observed accurately and continuously.

The magnetic field plays a critical role in determining the structure and dynamics of the corona. As input to many of the other experiments on SOHO a model of the coronal magnetic field will be essential for those investigations to interpret their results. Accordingly cooperation with other teams is an important responsibility of this team.

Outstanding Problems:

1. Determine the directional distribution of the magnetic field at the height where the 6768 line is emitted. It is important to correctly use the observed line-of-sight component of the photospheric field.

2. Estimate the global-scale horizontal electric currents flowing in the inner corona and their effects on the coronal field strength.

3. Determine parameters for the height of coronal helmet streamers. This can be used to determine the free parameter in Schatten's technique for modeling the heliospheric current sheet and the strength of the coronal field at greater heights.

4. Determine the height beyond which the solar wind totally controls the magnetic field. This can be used to fix the location of the ``source surface'' for modeling the effect of heliospheric volume currents.

5. Investigate the possible effect of the current sheets flowing between coronal holes and coronal helmet streamers.

Schedule:		Begin		End


Development Plan	93.11.17	94.01.17 		

• Complete outline plan (this document)

• Identify Responsible Programmer

• Prepare development plan

Implementation			94.01		95.03

• Develop mathematic model including effect of the heliospheric current sheet on the coro- nal field below the "cusp surface" as well as above the cusp surface.

Testing:

• Using WSO data in 1976 and 1984--1986

• Using MWO data in 1984--1986

• Using KPNO data of comparable spatial resolution

• Using GONG data of comparable temporal resolution

• Using available MDI calibration data

• Using density observations from coronagraph and coronameter instruments

Active / Knowledgeable Team Members:

 T. Hoeksema 	S. Kosovichev 	X. Zhao

Comparable Projects / Datasets:

Projected availability of GONG magnetic time series

---

TEAM SCIENCE OBJECTIVE: GOLF INTERCOMPARISON

Team Leader:		 	R. Ulrich


Local Coordinator:		R. Bogart


Responsible Programmer:		J. Aloise

Technical Summary:

Comparison of MDI data with GOLF data for mutual calibration as applicable. Because the MDI long-term stability is insufficient to be able to compare global Doppler averages with GOLF's measurements, the only planned intercomparison is the provision of MDI measurements of a suitable proxy for the magnetic field structures contaminating the GOLF signal. These GOLF magnetic proxy measurements will be part of the SOI Structure Program and included in the continuous low-rate telemetry. The required data processing therefore consists solely of extracting the GOLF magnetic proxy measurements from the low-rate telemetry, calibrating them, and producing a suitable dataset. The output dataset is a time series on uniform cadence of two-dimensional maps of the proxy values. The duration of the time series is the life of the mission, with no planned gaps. The cadence is to be determined; the current value is a tapered average at a rate of one per 20 minutes. The spatial resolution and mapping are also to be determined; the present plan is for boxcar averages of the values in the full-disc field into a 96*96 uniform grid, with only the pixels on disc reported. The estimated size of the data set is thus of the order of 1k values per minute, 1.5 M values per day, 500 M values per year. The manner in which the data are to be provided to the GOLF team is to be determined, as is the frequency of updates (probably not more than once per day nor less than once per month). Also requested are images at the same temporal and spatial resolution of either I2 or I2+I3. This quantity may be needed for the roll angle determination. If the Ic maps at 128*128 and the 20 time averages are adequate to distinguish between spots and non-spots, no additional quantity will be needed for the GOLF Intercomparison and the spatial grid for the magnetic proxy should be increased to 128*128.

Outstanding Problems:

• The manner in which the magnetic proxy is to measured is still to be finalized.

• There is no known procedure for calibrating the observations; it must be developed based on what is learned from the velocity and magnetic calibrations, plus modeling from what is known or can be determined from ground observations of line profiles and the MDI filter response.

• The temporal cadence, spatial resolution, and averaging procedures for the observa tions have not been finalized. The mapping of the furnished calibrated dataset is to be determined.

• The format of the low-rate telemetry is not yet well-defined.

Schedule:		Begin		End 


Development Plan	93.11.17	93.01.14 

• Complete outline plan (this document)

• Identify Responsible Programmer

• Prepare development plan

Implementation		93.01.17	93.05.31 ?

• Generation of artificial level 0 dataset

• Description of datasets for DSDS

• Function to generate (uncalibrated) datasets from artificial level 0 data

• Review IP procedures for generation of mag netic proxy

• Modify low-rate telemetry data processing to generate level 0 data

Testing			93.01.31 ?	93.07.29 ?	 		

• Function to mimic IP generation of proxy date from filtergrams: test and verify prox ies

• End-to-end verification from artificial raw data

• Verification of telemetry processing in con junction with onboard software development

Active / Knowledgeable Team Members:

	A. Cacciani	B. Gelly	T. Hoeksema	 	


	P. Delache	D. Gough	R. Ulrich	 


	E. Fossat	G. Grec


	A. Gabriel	C. Henney 	 

Comparable Projects / Datasets:

• IRIS (similar to GOLF)

• Mt. Wilson 150' measurements for line pro- files, GOLF response

---

Team Science Objective: Asphericity

Team Leader:


Local Coordinator:


Responsible Programmer:

Technical Summary:

Two-dimensional inversions of spherical harmonic mode frequencies from full-disc observations for latitudinal structure of sound speed, convective stability.

Schedule:

• Class C (long term)

Outstanding Problems:

Active / Knowledgeable Team Members:

D. Gough	J. Schou


A. Kosovichev	M. Thompson


J. Kuhn

Comparable Projects / Datasets:

• GONG

• Mt Wilson 60'

• Fourier Tach

• Big Bear

• NSO South Pole

---

TEAM SCIENCE OBJECTIVE: RADIAL STRUCTURE

Team Leader:


Local Coordinator:		


Responsible Programmer:

Technical Summary:

One-dimensional inversions of spherical harmonic mode frequencies from full-disc observations, comparison with models; analysis of temporal variations in structure

Schedule:

• Class B (medium term)

Outstanding Problems:

Active / Knowledgeable Team Members:

J. Christensen-Dalsgaard    A. Kosovichev	M. Thompson


W. Däppen	 	    J. Leibacher	R. Ulrich


C. Fröhlich	    		K. Libbrecht	M. Woodard


D. Gough		    J. Schou

Comparable Projects / Datasets:

• GONG

• VIRGO

• Mt Wilson 60'

• Fourier Tach

• Big Bear

• NSO South Pole

SOHO at the 1993 SPD

Special SOHO Session

A morning session of the Solar Physics Division meeting in July 1993 was devoted to SOHO and its science opportunities. Invited talks by Vicente Domingo ("Soho Operations and Coordination with Ground-Based Observatories") and Arthur Poland ("SOHO Coronal Observations") were followed by a panel discussion. Participants in the panel included Vicente Domingo and Martin Huber of ESA, Bill Wagner and Art Poland of NASA, Ken Schatten of the NSF, Ken Dere of the NRL, John Leibacher of NSO and GONG, Klaus Wilhelm of the Max-Planck-Institut representing SUMER, and Todd Hoeksema of Stanford representing MDI.

October '93 Team Meeting

Over 50 SOI team members from around the world gathered in Palo Alto for an informative meeting on October 14 and 15. Updates were presented on all aspects of instrument development and SSSC status. Potential problems and plans for use of data were discussed. Participants also toured Lockheed, in order to see the MDI instrument, then undergoing testing.

A booklet has been printed, including viewgraphs from the meeting, and has been mailed to all participants. If you were not at the meeting and would like to have a copy, please contact Margie Stehle.

Other New Deliveries

New Babies `Join' MDI Team!

It seems to be "baby season" in the SOI-MDI group this winter. The first to arrive was Madeline Margaret Berger, daughter of Stanford graduate student Tom Berger and wife Anne, born on December 7, 1993. She was 7lbs.6oz. and 19". Next arrival was Jake Austin Williams, son of EOF Operations Coordinator Scott and Kerry Williams. Born on February 1, 1994, he weighed 7 lbs. 1 oz. and was 20" long.

This baby boom is by no means ended yet. Todd and Carole Hoeksema are expecting a baby in mid- March, and Mons and Susan Morrison are expecting in May. The rest of us are hoping it isn't contagious.

The beguiling ideas about science quoted here were gleaned from essays, exams, and classroom discussions; most were from 10- and 11-year-olds. They illustrate Mark Twain's contention that "the most interesting information comes from children, for they tell all they know and then stop."

"While the earth seems to be knowingly keeping its distance from the sun, it is really only centrificating."

"Some people can tell what time it is by looking at the sun. But I have never been able to make out the numbers."

Spell Check Funnies

Being a Compendium of Learned Suggestions Made by the FrameMaker Spell Checker

apodization	podzolization


Carrington	carrying-on


deintegrated	denticulated


downflows	downfalls


DSOS		doses, douses, dozes, tzus


earthstrap	earthstars, airstrip, orthotropous


Harvard		hereford


LPARL		leper, liberal, libra, labor


MDIers		Midas


microflares	microfloras


nanoflares	nonofficials, mainframes


newsgroup	anestrous


Scherrer	securer, scarier, scorer, 

		succorer, scrawlier


Sunlab		singable


telecons	tycoons


upflows		peafowls, hopefuls, buffaloes,

		pilafs, bowlfuls, playoffs


Yale		ale

Technical Notes

(for a listing of previous Tech Notes, see the SOI-MDI Newsletter, Vol.1, or contact Margie Stehle at the address below)

SOI-TN-076	Johnson		Style Recommendations for SOI Scientific 
				Algorithms and Software

SOI-TN-077	Johnson		SSSC Prototyping Accomplishments and 
				Suggestions for Future Work

SOI-TN-078	Johnson		SSSC Prototyping, Phase 2

SOI-TN-079	Bogart et al	An Overview of the SOI Science Support Center

SOI-TN-080	Suryanarayanan	Backup and Recovery Strategy for the SOI-Catalog 				Database

SOI-TN-081	McWilliams & Kuhn Calculation of the Center of Full Sun Images

SOI-TN-082	Lin & Kuhn	On the Performance of the Gain Iterating 
				Algorithm with 1024x1024 Full-Disk CCD
				Solar Image

SOI-TN-083	McWilliams & Kuhn Instructions for Operation of SUNSTAR 
		and SERIES

SOI-TN-084	Kosovichev	Solar Structure Inversion Package

SOI-TN-085	Bogart & Surya	SOI FITS Keyword List

SOI-TN-086	Bacon		Apodization

SOI-TN-087	Bacon		Comparison of Interpolation Methods: 
				Bilinear and Cubic

SOI-TN-088	Bacon et al	SOI Source, Binary, and Library File Locations

SOI-TN-089	Ulrich & Henney	Determination of Roll Angle from Magnetic Field 
				Cross-Correlation

SOI-TN-090	Hoeksema et al	The Solar Oscillations Investigation - 
				Michelson Doppler Imager

SOI-TN-091	Kunnath & Johnson Distributed Computing Infrastructure for 
				the SSSC

SOI-TN-092	Johnson		Evaluation of OASIS-PS for SSSC Planning 
				and Scheduling

SOI-TN-093	Johnson & Kunnath Using C++ for SSSC Development

SOI-TN-094	Johnson		DSDS Feedback from Tuck Stebbins

SOI-TN-095	Bogart		Generation of Artificial Test Data 
				I. Individual Images

SOI-TN-096	Kosovichev	Optical Masks for Structure Program

SOI-TN-097	Milford		Proposal for a Different Set of APU Macros

SOI-TN-098	Scherrer et al	MDI Revised Structure Program

SOI-TN-099	Gough		On POX Strategy

SOI-TN-100	Suryanarayanan	SOI-MDI SSSC Conceptual Design

SOI-TN-101	Bogart		Lessons from the Analysis of Early MDI 
				Optics Package Test Data

SOI-TN-102	Tom		Internal and File Data Structures

SOI-TN-103	Bogart		A Standard for Binary Floating-Point 
				Arithmetic & Representations

SOI-TN-104	Bogart & Scherrer Naming of Datasets for SOI

SOI-TN-105	Aloise et al	Preliminary SSSC Conceptual Design

SOI-TN-106	Bogart et al.	The SOI Program Development Environment

SOI-TN-107	Bogart		Programming in the SOI Analysis Environment

SOI-TN-108	Bogart & Bacon	The SOI Analysis Library

SOI-TN-109	Aloise et al.	SSSC Implementation Version 1.0

SOI-TN-110	Scherrer	MDI IP Velocity Algorithm

SOI-TN-111	Bogart		An Atlas of MDI Ground Test Images 
				(not available by mail)

Copies of Technical Notes may be ordered from: Margie Stehle, mstehle@solar.stanford.edu

Last Modified: 15 February 1996