SOHO SPWG Minutes -September 20, 1996

September 20, 1996, SOHO EAF, GSCF
Chair: Piet Martens
Notes: Laura Allan


Project Scientists, SOC's,
Leaders for JOPs 3, 17, 33, 44, 52

0. Spacecraft roll for SWAN calibration and JOP002

SWAN representative requested time for S/C roll after November maneuver, for cross-hemispheric detector calibration. Preference for several days, but SWT decision limits these rolls to 16 hours maximum. EIT would like dwell at 45 degrees, and S/C off-set for calibration. SOC to produce draft timeline. JOP002 leader to evaluate May data. SWAN prefers roll opposite to the May one. UVCS would like to observe both poles; SOC will inform on roll-time implications.

1. Review of action items

1a) Old action items

* Open 5.3 -- Instrument teams to provide a list of SOLs. Richard Harrison supplied list of SOLs, other experiments still have to.

Long discussion (again!) on the role of SOLs. It was agreed that the experience with previous SOLs (Tarbell, Polettto) was positive, and that the concept is good. John Kohl suggested to have one of the JOP-leaders for that week as SOL.

1b) New action items

Item 9.1
Action on Piet Martens to provide timeline for November roll and S/C off-set.

The dates foreseen by FOT:

Nov. 20 Wednesday
Momentum Management
Nov. 21 Thursday
Perform 90 degree Roll (possibly JOP002) with a stop at 45 degrees for 15 min
Nov. 22 Friday
Momentum Management

EIT may want to do an off-pointing at some time.

Item 9.2
Action on Alan Gabriel to present reduction of JOP002 data from last time before deciding to repeat the observation.

2. Boundary conditions for the coming months

On Oct. 1 there will be a 6 hour memory dump.

MDI continuous Oct 17 to 21.

3. Priorities for the coming month

3a) Individual Instrument Plans


We get started with JOP003 as a matter of some urgency - extended periods of observations: 1 week/month for 3 months involves sitting on a filament for 6 hours per day. After some discussion, it was suggested that the weeks beginning October 7 / October 22 would be good rather than mid-November due to the SERTS launch and the momentum management activities.

Flows in Coronal Loops
CDS has a few independent Studies planned for October/November concerning coronal loops and these fall nicely into this scientific topic. They are not JOPs, however. We might like to define when they are, though, to allow simultaneous observations if other instruments choose to join in.

Low Latitude Coronal Holes.
This is a target of opportunity topic. We all have coronal hole Studies which could be used to observe such regions but it may be better for the teams to discuss how to co-ordinate the Studies.


   Planners will be:
		week 41:	Terry Kucera
		week 42:	Jung Chulchae
		week 43:	Tom Ayres

		Oct. 13 ->	Roberto Falciani: Sac Peak study of AR's
		Oct. 21 ->	Tenerife/SUMER, EOF: Philip Lemaine


   Sept. 30 - Oct. 6	Martin Huber	   Polar Plumes
   Oct.   7 - Oct. 13	John Kohl	   Spectrometric Intercal
                                            with SUMER
					   Dynamics of equatorial
                                            regions with LASCO.
   Oct.  14 - Oct. 20	Larry Garder	   Calibration
   Oct.  21 - Oct. 27	Larry Garder	   Calibration
   Oct.  28 - Nov. 3	John Kohl	   Dynamics of equatorial
                                            regions with LASCO
   Nov.   4 - Nov. 10	Silvano Fineschi   Doppler dimming and IPS
   Nov.  11 - Nov. 17	Giannina Poletto   Serts on 11/13-14
   Nov.  18 - Nov. 23	Angela Ciaravella  JOP009
   Nov.  24 - Nov. 27	John Raymond	   delta sco, beta sco, 
                                            pi sco, nu sco
   Nov.  28 - Dec. 1	Ester Antonucci	   Recommend JOP2
   Dec.   2 - Dec. 9	Silvio Giordano	   Recommend JOP2
   Dec.  10 - Dec. 17	Ruth Esser	   Sami Solanki (JOP55)?
   Dec.  18 - Dec. 22	John Raymond

John Kohl would like to do JOP55 during a different week (Dec. 10-17)

SUMER also suggested doing omega1 Sco on November 24 also.

UVCS would like to do CME observations between Oct 28 - Nov 3.


Synoptic program with LASCO was foreseen to take up 50-80% of their time. The remainder would be left for special observations. LASCO depends heavily on data compression (there are 4 unique algorithms). RICE compression works exceedingly well and is the compression format of choice. Adaptive Discrete Cosine Transform (ADCT) is a less useful algorithm than initially planned (due to large numbers of cosmic ray hits).

LASCO is seeing more dynamic range in images then was previously anticipated. ADCT compression causes subtle effects to be lost. Synoptic program with RICE compression fills all observing time. When people want to do special observations and are seeing IAPs w/same thing every day - that's the way it is. LASCO synoptic program is the backbone of white light coronal observations; also includes polarization brightness measurements. Will have daily polarization and color sequences. The good news is that the synoptic program is sufficient to support most collaborations requirements.


EIT has been operating with a few constraints: No multi-spectral observations done during non-contact time due to trouble had few weeks ago with the stuck sector wheel.

Jim Lemen will perform active region, and DEM temperatures densities studies.

Oct. 1-6: JOP20 - taking a lot of time during that week.

EIT also suggest re-running JOP020 with a slower cadence: another run with 7-minute cadence over a longer period of time. EIT may also want to run more Coronal Loop Footpoint studies especially if in October the region is in MDI's Hi-Res field-of-view.

EIT argues strongly for more TLM bandwidth.

EIT prefers to get full-field rather than subfield image since the latter may cause damage to their detector in the pixels not read out.


During the continuous time in October from 8-15 UT, Ted Tarbell will be trying to get La Palma support. In other weeks, there will be 3-day blocks for helioseismology and MDI is open to suggestions for the other times during the week. Other priorities include Polar Plumes and Coronal Hole observations. Also JOP052.

MDI showed viewgraph of long-term pointing stability and are still not sure what caused mid-August pointing correction (CELIAS CTOF anomaly took place on 18/19 August).




Nominal. All staying in the same mode

3b) Calibration plans

  • Intercal 2 - awaiting revisions from CDS and EIT
  • SUMER runs intercal 1 every 2 weeks
  • SICWG holds brief meeting after SPWG to define matters a bit more, and will produce schedule.
  • 3c) Joint Plans

    During weeks 41 and 44, CDS/SUMER would like to look at energetics of eruptive limb prominences (JOP003/JOP0017). BBSO could provide H-alpha images every minute. Also like to run starting the week of Nov. 11 for 2 weeks. In addition, would like to run roughly Dec. 17/22-31.

    4. JOPS Status

    Doug Biesecker and Sarah Gibson will give a brief presentation at the November SWT. On Feb. 10-11, they will organize a small workshop at GSFC to discuss JOP044 results. The first day they will present observations/models and on the second day they will discuss observations. At AGU meeting in May, they intend to have a special session for JOP044 results. All agree, we need to look at data more before making decision to run JOP44 again.

    5. New JOPS

    There are many new joint observing programs: JOPs 51-55. See Web pages for details.

    Lyndsay Fletcher proposes to run JOP033 starting Oct 13 and again on Nov 8. JOP033 will run 3-4 hours per day, 3 days when appearing on the limb (both East and West), and once on the disk. CDS, SUMER, Yohkoh BCS, will participate; for limb targets add EIT and UVCS. SUMER and CDS programs have been tested for this.

    6. Workshops


    ----- Included Message -----
               Hugh Hudson  (Yohkoh/SXT)
               Piet Martens (SOHO Science Operations Coordinator)
    We have been brainstorming on the idea of SOHO-Yohkoh workshops. 
    We came up with the idea for a format very similar to the very 
    succesful CDAW workshops that the Hawaii and SXT people have held
    The following is a synopsis of our ideas.
    FORMAT:   Small (< 20 people) weeklong workshops on very narrowly 
              focussed subjects, with about half discussions, and half
              working sessions around workstations.
              Sufficient and powerful workstations, easy access to SOHO
              and Yohkoh data archives. Sufficient workspaces. Commitment
              and detailed preparation by participants.
    CADENCE:  Twice a year. Need good planning concept, say, March '97 
              equinox, and every equinox thereafter.
    LOCATION: GSFC and ISAS (reduces travel needs; requirements met). I
              volunteered to organize the first one at GSFC, so that the 
              Yohkoh people can familiarize themselves with the way SOHO
              operates. Later places like Lockheed, Bozeman, Medoc, and
              RAL may be appropriate.
              No Proceedings, but (this would be a new wrinkle) Web 
              summaries of the activities. Acknowledgements in papers
              encouraged. Preparation grunt work (like calibrations and
              co-alignment) can also be done jointly through Web pages.
              Hugh and I will do the leg work for the initial meetings.
              After that I hope the thing will get a life of its own, 
              and local organizers do most of the work. We envisage an
              official "organizing" or "steering" committee with (at least)
              one representative for each PI team involved. That group 
              would take the decisions on meeting subjects, locations,
              dates, and participants, as well as the sensitive subject of
              data rights -- although I expect that this will be less of
              an issue by March '97, and fade away after that.
    SUBJECTS: Initially we may want to focus on topology types of subjects,
              to avoid calibration issues that are not yet resolved. 
              A list of subjects mentioned:
              * AR Region Development (e.g. JOP018)
              * Emerging/Disappearing Flux and Coronal Effects (e.g. JOP001)
              * Eruptions and CME's
              * Bright Points
              * Plumes (several campaigns and JOPs)
              * Jets
              * Filaments and Prominences (several JOPs)
              * Coronal Loop Structure Defined by Yohkoh and by SOHO
              * Yohkoh-SOHO Intercalibrations and Temperature Determinations
    ----- End Included Message -----