SSOC Tohban's Report for Week 31 (26-Jul-99 -- 1-Aug-99) SSOC: N. Shinohara, T. Watanabe and T. Sakao KSC: S. Kato, S. Kubo@SSOC 0. Meeting Attendance M. Akioka, H. Hudson, T. Naito, Y. Ogawara, T. Sakao, M. Sawa, T. Watanabe -------------------------------------------------------------- 1. Solar Activity Solar activity was high during week 31. While the steady-state GOES class stayed at around C1 (with occasional flares) in the first half of the week, it increased to C2-C3 after July 28 due to the appearance of NOAA AR 8651 over the east limb. Six M class flares occurred between July 26 and 31, with the largest one (M5.1) in AR 8651 on July 29. Among the 6 flares, 3 commenced during Yohkoh daytime, including the M5.1 flare. Another M-class flare commenced around 0-1 UT, 2-Aug-99, also during Yohkoh daytime. -------------------------------------------------------------- 2. Standard Operations 2.1 SXT Table Uploads The following SXT tables were uploaded during week 31. ===================================================== JST Date Pass Table ID ===================================================== 26-Jul-99 (Mon) 2 990726 P2 ARS1 STANDARD 27-Jul-99 (Tue) 5 990727 P2 ARS1 DARK 28-Jul-99 (Wed) 3 990728 P3 ARS1 DIFFUSE 29-Jul-99 (Thu) 3 990729 P3 ARS1 STD 30-Jul-99 (Fri) 3 990730 P3 ARS1 STD 31-Jul-99 (Sat) 2 990731 P2 ARS1 STANDARD 1-Aug-99 (Sun) 4 990801 P4 ARS1 STD ===================================================== 2.2 STT Timer setting STT timer was set in Pass 5 of 27-Jul-99. The next Timer Set should be on Monday, 2-Aug-99 (UT). -------------------------------------------------------------- 3. Special Operations We carried out normal pointing update in Pass 3 on 31-Jul-99 (JST). The new pointing direction is "S/C W.923 N.545". Revised OG-32 (dec) was uploaded in the above pass, immediately followed by re-pointing of the S/C (by the real-time OG). -------------------------------------------------------------- 4. Errors and Problems 4.1 BCS Errors A BCS error was found in Pass 1 on July 26. The error recovery was postponed until Pass 4 next day. See 4.3 for the explanation to this. 4.2 SXT Errors An SXT error was found in Pass 4 on July 26, and a Yobi-A command was issued in the same pass. Together with BCS, the error was recovered in Pass 4 next day. 4.3 Non-start of OP after the operation break by Typhoon 5. The first pass early morning of July 27 (TUE) JST was cancelled due to strong wind by Typhoon 5. The action to track the second pass (990726-1443) was taken only about 20 minutes before AOS. Command planning was confused very much: Tohbans thought to do all the menu originally scheduled both at 1st and 2nd passes, namely, to upload OP, to start it from the 2nd pass, to recover SXT and BCS, to set up STT timer. NEC operator overlooked the timings of antenna changes and OP CONT. As a result, OP started at the third pass, both SXT and BCS were completely recovered at fourth pass, and SXT table of the day was uploaded at the fifth pass with no mainframe comparison. -------------------------------------------------------------- 5. NASA Station Scheduling 5.1 Contact pass cancels/additions The following DSN/NASA passes were added/deleted: =================================================================== DSN/NASA Schedule Week Schedule Changes =================================================================== Real-time 31 1 cancellation by SSOC Final 32 8 cancellations by SSOC Preliminary 33 3 cancellations by SSOC Strawman 34 64 cancellations by SSOC =================================================================== 5.2 Data Transmission from NASA Ground Stations -(From /home/flare1/yohkoh/dsn_corrupt/99_31)--------------- 201 80 1524 corrupted tape requested 26-Jul Closed/ correct data 201 80 1706 corrupted tape requested 26-Jul Closed/ correct data 201 80 1849 corrupted tape requested 26-Jul Closed/ correct data 202 74 2239 corrupted tape requested 26-Jul Closed/ same data 209 82 1523 corrupted tape requested 28-Jul 210 74 1408 corrupted tape requested 28-Jul -------------------------------------------------------------- -------------------------------------------------------------- 6. KSC Pass Conflicts and Schedule In Week 31, 9 KSC contacts were lost, 8 for Asca, 1 for Halca. In Week 32, 11 KSC contacts will be lost, 4 for Akebono, 7 for Aska. Note: For future weeks, it would be nice if Yohkoh could get passes 4 and 5 prior to each weekend operation, and passes 1 and 2 immediately following. This would aid in DSN scheduling. -------------------------------------------------------------- 7. Hikitsugi Items 7.1 Tohbans for week 32 SSOC: T. Naito, M. Akioka KSC: M. Otogawa, K. Yoshimura 7.2 STT timer setting The next STT TIMER SET is due on 2-Aug-99 (UT). Pass 1 or 2 are preferred as they contain Night periods. 7.3 Holiday Schedule Next Yohkoh holiday will be Sunday, 8-Aug-99 (UT). 7.4 KSC pass reservation for eclipse observations This week's tohbans (W32) are requested to reserve, in the Thursday meeting, the first three KSC passes on August 11 (11:35, 13:15 and 15:00 UT on that day) for eclipse observations. 7.5 If possible, please schedule terminator opportunities on any weekend table (ie, if room permits). 7.6 KSC pass conflicts (from earlier weeks) ASCA conflicts cause the loss of about 10 KSC contacts per week at this time. We do not know which contacts Yohkoh will lose until the weekly meeting. Santiago contacts occur on the same orbits as KSC contacts. Therefore, keep as many Santiago contacts as possible in the DSN Strawman and Preliminary Forecasts. 7.7 Command glossary We need a shorthand glossary for common OP and command-sheet commands. This already exists pretty much in the Sakao manual in Japanese, and the Week 26 tohbans started accumulating an English version on "yohkoh.glossary" 7.8 Yohkoh's Total Solar Eclipse of 11-Aug-1999 According to Dr. Mitsuru Soma (NAOJ)'s calculation, Yohkoh will be able to see partial eclipses twice this time. The maximum depth of the eclipse was predicted about 55% (sun-moon center distance = 695 arcsec) at 13h6m37s UT. His prediction will be revised, when the latest Yohkoh orbital elements become available prior to the eclipse. === END ===