SSOC Tohban's Report for Week 17 (19-APR-99 -- 26-APR-99) SSOC : K. Matsuzaki and H. Nakajima KSC : M. Hagino and K.Kobayashi/S. Masuda 0. Meeting Attendance H. Hudson, M. Nishino, A. Starling, D. McKenzie, R. Canfield, M. Sawa, T. Watanabe, K. Matsuzaki -------------------------------------------------------------- 1. Solar Activity Solar activity was low during Week 17, with several flares as large as C-class (see plot). -------------------------------------------------------------- 2. Standard Operations 2.1 SXT Table Uploads The following SXT tables were uploaded during week 16: ===================================================== JST Date Pass Table ID ===================================================== 18-APR-99 2 990418 P2 ARS2 STARE 19-APR-99 2 990419 P2 ARS2 STADA 20-APR-99 2 990420 P2 ARS2 STADI 20-APR-99 4 990420 P4 ARS2 STARE 23-APR-99 3 990423 P3 ARS2 STARE ===================================================== 2.2 STT Timer setting STT timer was set during pass 2 on 20-APR-99 (JST). -------------------------------------------------------------- 3. Special Operations 3.1 HXT calibration HXT calibration was conductet during pass 1 & pass 2 on Friday (23 APR). -------------------------------------------------------------- 4. Errors and Problems 4.1 BCS Errors: None 4.2 SXT Errors: None 4.3 KSC workstation flare4 Due to a sudden power-outage at 7:00 JST on 23-Apr-99, flare4 workstation at KSC was out of order. Shimojo-san will fix this machine when he is doing KSC tohban during next week (w18). 5. NASA Station Scheduling 5.1 Contact pass cancels/adds The following DSN/NASA passes were added/deleted: =================================================================== DSN/NASA Schedule Week Schedule Changes =================================================================== Realtime 17 3 pass deleted by SSOC Final 18 4 pass deleted by SSOC (Santiago/KSC) Preliminary 19 2 passes deleted by SSOC Strawman 20 66 passes deleted by SSOC =================================================================== 5.2 Data Transmission from NASA Ground Stations -(From /home/flare1/yohkoh/dsn_corrupt/99_17)------------ 099 80 1646 not received requested 14 Apr Closed/ correct dat a 107 80 1340 not received requested 21 Apr Closed/ correct data 109 80 1554 corrupted tape requested 23 Apr 110 80 0738 corrupted tape requested 23 Apr 110 80 0918 corrupted tape requested 23 Apr 107 80 1707 Data drop outs due to masking. -------------------------------------------------------------- 6. KSC Pass Conflicts and Schedule 6.1 Weekly conflict meeting In week 18, 9 KSC contacts to ASCA, 0 to AKEBONO. 6.2 KSC - Santiago downlinks The Santiago station of the DSN lies on the same orbits as KSC. Santiago passes are valuable for times when Yohkoh loses contacts to spacecraft conflicts. The weekly conflict meeting for Week 18 occurs after the arrival of the DSN Final schedule for Week 18. Therefore, we must cancel or add Santiago contacts at Final. However, the orbital predictions for the spacecraft are accurate enough to allow the creation of the DSN Strawman Forecast for Week 20. Better planning of DSN Santiago contacts could be made if the KSC conflict meeting was used to look farther into the future. During Week 17, we should be determining the KSC conflicts for Week 20. That would permit better use of KSC and DSN resources. Number of contacts for Santiago station for Yohkoh+ASCA is limited to three. Since conflicts of KSC and Santiago stations are coupled ploblem, use of Santiago station also should be discussed after conflict meetings on Thursday (Wednesday in this week). -------------------------------------------------------------- 7. Hikitsugi Items 7.1 Tohbans for week 18 SSOC: M. Nishio and R. Canfield KSC: S. Masuda and M. Shimojo 7.2 STT timer setting STT timer setting is due on Tuesday, 27-Apr-99 (JST) 7.3 Holiday Schedule The next holiday will be Monday, 3-May-99 (JST). 7.4 KSC/ASCA conflict meeting It is held on Wednesday (28-Apr-99) this week, because the next day is a national holiday. 7.5 Elevation (from previous week) SSOC Tohbans need to examine the maximum elevation when checking the DSN final schedule, because the maximum elevation may change from the strawman to final schedule due to changing orbital elements. DSN requires a maximum elevation more than 7 degrees . This is listed in the English language manual, but not the Japanese language manual. If this information is put in the manual we can delete this item from hikitsugi. 7.6 KSC pass conflicts (from previous week) 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 Some Problems in OP_FIRST_GUESS (from previous week) The BDR optimization changes the DP mode between Quiet Medium and Quiet High. The algorithm chooses to end a contact in Medium rate, then switch to High rate later, to be in High rate for the next contact. During this week, the switch to High rate occurred just before entering SAA during orbit day in the following cases: 12-APR-99 16:20 UT 12-APR-99 21:28 UT 13-APR-99 16:35 UT 14-APR-99 20:02 UT 15-APR-99 15:23 UT 16-APR-99 13:40 UT (Short SAA, then terminator at 14:15) 17-APR-99 14:11 UT 19-APR-99 12:40 UT These cases seem very unfortunate in their choice of time to go to High rate. Perhaps the BDR optimization and SAA data rate parts of the code should be studied to see if an improvment is possible. 7.8 Campaigns There was an observing campaign with TRACE, Big Bear, Mees, and SXT to observe the active region (AR8518). This will continue during next week. 7.9 Discussions in WOM (12-APR-99) (from previous week) -- Yohkoh data distribution Distribution of data to sites in Japan and the US is slow at this time because of the limited manpower available to reproduce the tapes and/or CDs. With the improvement of network connections, perhaps a system of electronic distribution should be considered as a way to speed the distribution. === END ===