Notes from SOHO daily meeting, 18 April 1996 -------------------------------------------- Chair Eliane Larduinat; notes taken by Julia Saba/MDI Announcements: ------------- Transfer and uplink of MDI background queue files was successful. However, the queue had to be disabled yesterday because uploading the files was interfering with MDI instrument operations. It appeared that a file was uplinked from the nominally disabled queue a few times when the NRT link was paused and reenabled. Eliane thinks this might be an ECS display problem rather than a queue management problem. The EOF is checking this out. FOT report (from Bud Benefield): ------------------------------- - Guide star: Switched back to magnitude 7.1 guide star. Tomorrow we lose a star that's being tracked, and gain a new star with magnitude 5.7. The FOT will need an hour at the beginning of the pass to acquire the new star. - VC2: Yesterday there was extra VC2 for MDI to realign (and recover from problem related to the background queue load) after the spacecraft repoint. - Limits policy: From now on, yellow limits will be logged by the FOT; the OE will be called for red limits, unless the FOT is instructed to ignore limit violations by the respective instrument team. [It is not clear what version of the limits database is being used, or when the new one will be implemented.] - Station testing: DSS24 was used successfully yesterday. The NASA policy is that a station will be used for a week of successful contacts before it is put in the schedule. - Commanding glitch: There was a command lost yesterday, concurrent with data loss by the FOT; data were not lost by PACOR, hence it was not a station problem. Instrument status and schedule update: ------------------------------------- GOLF: has been taking continuous data for 7 days now; no change. VIRGO: nominal, working on getting good data. A few days ago, a time-tagged VIRGO command was not uploaded due to a conflict with NRT commands. That kept VIRGO from getting data that day. [The FOT is now pausing the NRT link when VIRGO commands need to be uplinked.] MDI: preparing for 80-hour continuous dynamics run next week, and continuing to work on flat field table for upload via background queue. With the extra VC2 allotment yesterday, MDI: - Did dump to diagnose background queue upload problems. - Recentered after the spacecraft repointing by moving the legs and PZTs. - Ran a jitter test to monitor spacecraft reaction wheels. - Ran full-disk and high-resolution focus tests. Without VC2, MDI: - Ran a correlation tracking program when off-centered, to understand systematic errors in (centered) flow maps. - Got a Michelson calibration data set before continuous structure begins. - Ran several shutter tests to diagnose a possible anomaly. MDI is requesting 2 hours of VC2 during the NRT period for the next six days, beginning today, for tests of table loads and software patches in preparation for the continuous structure/dynamics run. [An OCD for this is requested by the FOT.] SUMER: is happy. Did work on explosive events, and a study of the _East_ limb streamer. This latter was a change from the planned West limb study, to coordinate with UVCS. CDS: ran abundance studies, and made a full-Sun synoptic map. They will do abundance studies again today. Tomorrow, they will make coronal hole observations for JOP 35, with the position TBD. EIT: nominal. Did not get their normal synoptic data set due to the LASCO repoint and loads. Have been taking 195A images every hour. Hope to support JOP 35 tomorrow, if the LASCO schedule permits. LASCO: completed their repoint and also their upload, but have not yet rebooted, so the load is not yet verified. They plan to observe the East limb streamer, and provide coordinates to UVCS. UVCS: running their synoptic program at night. Will observe at 1.5 R_sun simultaneously with SUMER. They will study small scale structure in the streamer. Tomorrow they will obtain line profiles in the streamer, using LASCO input on the best target. SWAN: has been having a problem with sporadic tripoff and a motor. They will be doing a major software patch Monday with heavy use of NRT commanding. Showed a nice picture of Comet Hyakutake in Lyman alpha from 28 March. It now covers 1/4th of the sky -- about 60 degrees. The Big Dipper appeared small in comparison (< 1/3rd). There are an estimated six tons of water vapor in the nucleus. The Lyman alpha map showed an extensive hydrogen cloud in the upstream direction; the southern hemisphere is fainter, perhaps because of the large solar coronal hole in the south, whose wind may sweep out the interstellar hydrogen. COSTEP: nominal, everything working. The Sun is calm, with no major particle flux. Other intruments not represented. Coordinated observations: ------------------------ JOP 035: CDS and SUMER need to decide pointing. EIT will image the full Sun. MDI will make full disk magnetograms every 96-minutes when possible within structure test constraints. Intercal 002: postponed until next week. Solar conditions: ---------------- An EIT image in 195A showed that the finger in the S. polar coronal hole is fading. A possible target for JOP 35 is a dark area in the NW part of the southern hole. Planning: -------- The planning tool now has back the yellow bars noting SVM activities. Meetings: -------- - Weekly meeting: Today at 3:30 pm EDT in the EOF. - Friday's daily meeting: Tomorrow at 9 am EDT in the EOF. - SPWG: Tomorrow in the EAF at 10 am EDT (_NOT_ at 11 am, as advertised last week in the weekly notes). Other business: -------------- Helmut Schweitzer (ESA) pointed out that the spacecraft had a major SEU hit on Day 104 at 15:06 UTC, about an hour before a contact period. Instrumenters are advised/requested to see if they noticed any concurrent effect.