SOHO SPWG Minutes
SPWG FINAL MINUTES
Friday 19 December 2003
1. Boundary conditions
* SOHO is at the nominal roll position until December 30. After
the roll on December 30, SOHO will be "up side down" until the
* The next manoeuvre is planned for December 30. It will include a
station keeping (SK), momentum management (MM), and an 180 degree
roll. See http://soho.nascom.nasa.gov/soc/2003_Dec_sk_mm_roll for
details. The following manoeuvre will be during the spring keyhole
(March 15 - April 7).
* Keyhole estimates are being fine-tuned based on experiences gained
during the past two keyholes. Changes in duration of 1 to 2 days are
The scheduling windows for the next 2 keyhole periods are given
below. For estimated keyhole dates through 2006 follow this link
* Dec 23 High Rate on 26m stations ends, TBC
* Dec 26 High Rate on 34m stations ends, TBC
* Jan 5, 2004 High Rate on 34m stations starts, TBC
* Jan 8, 2004 High Rate on 26m stations starts, TBC
* Mar 15,2004 High Rate on 26m stations ends, TBC
* Mar 19,2004 High Rate on 34m stations ends, TBC
* Apr 4, 2004 High Rate on 34m stations starts, TBC
* Apr 8, 2004 High Rate on 26m stations starts, TBC
For the winter keyhole, losses of VC0 and VC1 (housekeeping and
medium rate science telemetry) are expected to start on December 27
at about 00:30 UT and end on January 6 at 09:00 UT, if there are NO
GROUND OR SPACECRAFT ANOMALIES interfering with the currently
There is a possibility that very small losses will occur right
before 19:50 UT on Dec 26, right after 11:45 UT on Dec 26 and right
after 23:45 UT on Dec 25, due to limited dumping capability for
No MDI high rate is expected between the D34 pass on December 25
and the D54 or D24 passes on January 6.
In order to preserve VIRGO calibration sequences throughout the
keyhole period, short recording sessions have been inserted in the
schedule based on a simulation of the entire keyhole.
Between December 27 at 00:30 UT and January 6 at 09:00 UT, VC0/1
telemetry can only be expected for the scheduled passes and
The DSN schedule (including planned recording sessions) can be found
at http://soho.nascom.nasa.gov/soc/keyhole.dec03 (changed to reflect
the latest schedule and confirmed recording sessions).
A graphical representation of the winter keyhole simulation can be
found at http://soho.nascom.nasa.gov/soc/keyhole_dec03.pdf (changed
to reflect the latest schedule and confirmed recording sessions).
See AOB section for more details.
We are attempting to get off-line support from the ESA ground
station New Norcia (western Australia); data would be recorded and
shipped on a delayed basis. No commanding, obviously, and a
proof-of-concept is yet to be demonstrated (a test is planned for
this week). New Norcia is primarily dedicated to Mars mission
support (as are the large DSN stations), so additional time will be
limited. We expect Medium Rate only on this station.
A test of switching from the Tape Recorder to the SSR via time
tagged commands was performed successfully on Thursday December 18;
the capability will be used during the gap between D15/D27 and D54,
on Jan 8 2003.
Unless a Major Flare Watch is in progress, TRACE will be doing full
disk mosaics if/when EIT is not able to do synoptic sets due to
* MDI continuous contacts
Jan 28-Feb 2 MDI Continuous Contact
Mar 3-8 MDI Continuous Contact, TBC
* Submodes: Submode 6 until after March/April keyhole (about April 9)
Details on next SOHO/Ulysses quadrature and next MEDOC
* EIT Bakeout/CalRock/Shutterless/Other:
* Dec 26-Jan 5 EIT Bakeout
* Feb 18, 25 EIT Shutterless Run #14
NOTE: All shutterless and bakeout dates are obviously TBD with keyhole
operations. Presumably, bakeouts will be scheduled preferentially during
periods with poor DSN coverage.
TRACE will support the shutterless runs.
* Commanding outlook: See AOB section.
* Long-term DSN outlook: November 1, 2003 - March 1, 2004 is a very
heavily subscribed time for DSN. We may see less contact time than
we are used to. No data loss is expected (outside keyhole times),
but some days will have awkward commanding times (no Goldstone
* TRACE is now in eclipse season. Eclipse season ends some time in
February. During eclipse season, TRACE will only load plans on
Mondays, Wednesdays, and Fridays.
* Venus Transit: We have asked for DSN coverage for 5 hours either
side of the projected closest approach of Venus (June 8, 2004, 13:30
UT). Status is yet TBD. This will be a coronal transit only seen
from SOHO, and we will likely be in record during the most relevant
time period, (subject to approval from MDI). MDI requests that NO
stored Magnetograms be lost during the Venus transit, thus, possibly
restricting the maximum time SOHO will be in record. VC2 periods
will be inserted (timing may be dependent on downlink quality) as
needed to preserve all magnetograms.
Details from FDF as of November 2002 can be found at
http://soho.nascom.nasa.gov/soc/venus-transit.txt. Other relevant
intformation (the transit as seen from Earth) can be found at
We will ask for an update of the timing and closest approach early
next year, based on the latest orbit update. An ephemeris will be
requested somewhat later, when orbit uncertainties are small enough
to warrant the effort.
2. Priorities for the coming month & more
a) Joint observing plans and campaigns
No joint observations on the horizon for this month - courtesy of
the TRACE eclipse season and the SOHO winter keyhole, we presume.
* JOP159 CMEs in Lyman-alpha (#6870), SWAN/LASCO/EIT/UVCS,
POC: Chris St Cyr, Eric Quemerais
Targets of opportunity for the whole period:
* JOP136/MMOP009 Default RHESSI collaboration (#6850)
* JOP153/MMOP003 Major Flare Watch (#7020)
Campaign #6850 is for "individual instrument studies" selecting an
AR target [partially] influenced by the Max Millennium target. This
target will be observed by a significant number of ground based
observatories, so chances for serendipitous co-observations are
b) Intercalibration activities
Last Intercal 1: December 10 (Week 50)
* Week 02 Intercal 1, CDS/EIT
c) Individual instrument plans
See section 1 (boundary conditions) for MDI continuous contact periods.
MDI will attempt to downlink Magnetograms in the 5k data stream during
the keyhole. Exact timing of when MDI will start Mag downlink in 5k
stream during the December keyhole is TBD.
All requests for MDI support need to be made several months ahead of
time and sent to email@example.com.
MDI's REQUEST page is at http://mdisas.nascom.nasa.gov/coordination.txt
NOTE: Listing of a study on that page means *only* that a request has
been received, not that it will necessarily be supported.
See their planning page (below) and the SOHO calendar for weekly plans.
The following are listed because of NRT requirements or as candidates
for collaboration (with e.g. CDS):
* Dec 18-25 Observations of the North Coronal Hole
* Dec 26-31 Observations of Coronal Hole
* Jan 1-8 Observations of Coronal Holes
* Jan 9-18 Observations of the North Coronal Hole
* Jan 19-25 UVCS Streamer Study
During the December keyhole period, UVCS plans to observe as much time
as allowed by DSN contacts and recordings.
See their request diary for details
See section 1 (boundary conditions) for EIT bakeouts/shutterless and
other special items.
Expect EIT bakeout 2003 December 26 - 2004 January 5, assuming enough
contact on the latter date to run post-bakeout cals
NOTE that TRACE in general reserves the right to withdraw support from
agreed, existing collaborations if a sufficiently "good active region"
is called by the Max Millennium group.
TRACE is in hard eclipse since November 3, and will likely not agree to
participate in JOPs during eclipse season other than those already agreed to.
During eclipse season, TRACE will only load plans on Mondays,
Wednesdays, and Fridays.
* Next SPWG: Friday January 30, right after weekly meeting in the EOF.
* A graphical representation of the winter keyhole simulation can be
found at http://soho.nascom.nasa.gov/soc/keyhole_dec03.pdf
The plots have legends, but additional comments (and some patience)
may be necessary to decipher the contents (feel free to send
questions to SOCs):
The upper plot should be more or less self-explanatory (just showing
the passes & expected capabilities - high or medium rate - during
the passes). The lower plot needs some more explanation:
The Y axis is "hours on the Tape + Solid State Recorder", and the
zig-zag line throughout is the total amount stored on those as a
function of time, with the scheduled usage. Plateaus/peaks on this
line are annotated with the number of minutes on the
recorder. There's a "ruler" showing the delay times (12.8/25.6
hours) of VIRGO's 2 redundant data streams (for mechanical/visual
Dashed lines indicate the capacity of the Tape Recorder (320 min)
Solid State Recorder (640 min) and the sum of the two (960 min).
Passes are indicated by brackets (same times as upper plot, just to
aid the eye).
The blue line shows when recording is done (zero when no recording,
12 during recording).
The dark-greenish line shows *contingency* recording sessions,
scheduled during passes . They will only be effective in case of
problems acquiring telemetry during the pass.
Contingency recordings that may occur during gaps, based on earlier
failed or noisy downlinks, are NOT shown in this plot; the actual
amount of data on the recorders will increase if any contingency
recording is used.
The thick pink line is present when there's an expected loss of
VC0/1 (no pass, no recording). The thin green line, split on 3
levels (1, 2, and 3) shows the "redundancy" of VIRGO data as a
function of time. When it is not 1, 2, and 3, it is a red line at
zero (the "VIRGO loss line").
The thick green line segments at Y=4.5 shows recorded VIRGO PMO
calibrations. The VIRGO loss line is also plotted in pink at this
level to be easier to pick out.
A thick red line (not present in the plot, but would be at same
level as the thick green line) would show any lost calibrations.
The green numbers below the plot are ESTIMATED AMOUNTS of MDI VC2
(position is not indicative of the exact timing).
* DSN support should be requested at least 6 months in advance. Keep
this in mind for: ground-based collaborations that require MDI
support, stellar/shutterless observations that require NRT, etc.
* If anyone has projects that require high-cadence MDI support, now is a
good time to ask! If you need MDI data, make sure you request it
specifically. There is no significant change in the shutter
performance over the last 10 months; monitoring continues, but no
immediate changes in operations are planned.
* Commanding outlook
NOTE: Early Sunday, January 4 is probably last chance to cmd until
Tuesday, January 6, due to downlink stations.
Week 52 - Dec 22 - Dec 28: May lose HR on 26m stations Tuesday, and on 34m
stations Friday. Long gap Monday morning, multiple
gaps on other days. Mostly station pairs (one
uplink and one downlink) after early Wednesday.
DSS-27 on Monday and Wednesday.
Week 01 - Dec 29 - Jan 04: Contact for 4 hours in early morning and late
afternoon for safing on Monday. Maneuvers on
Tuesday after 15 UT. Wednesday through Friday
short early morning contacts and 5-6 hours of
contact in afternoons. Two very short contacts
on Saturday. NOTE: Sunday morning's early
contact is best chance of commanding until the
following Tuesday because of downlink-only
Week 02 - Jan 05 - Jan 11: No NRT on Monday unless very early.
Longest contacts in afternoons on Tuesday
through Friday. Good commanding on
Week 03 - Jan 12 - Jan 18: 5-hour gap at 13:40 UT Monday, then afternoon gaps
every afternoon but Saturday. DSS-27 through
Wednesday and on Saturday.
Week 04 - Jan 19 - Jan 25: Best commanding on Friday. Large gaps Tuesday,
Wednesday and Thursday. Afternoon commanding
best on Tuesday and Wednesday, morning best
on Thursday. 2-hour morning gaps on weekend.
DSS-27 Monday, Wednesday and weekend.
Week 05 - Jan 26 - Feb 01: Gaps during commanding times Monday, Tuesday and
Friday. Downlink-only station early Thursday.
Continuous contact starts early Wednesday but
Friday's gap is over 3 hours. DSS-27 Monday,
Wednesday and weekend.