SSOC Tohban Report for Week 36 (10-Sep-2001 -- 16-Sep-2001) SSOC Tohbans : H.S.Hudson & S.Kubo KSC Tohbans : K.Fujiki & J.Kiyohara 0. Meeting Attendees H.S. Hudson, A. Takeda, K. Yoshimura, S. Kubo, L. Fletcher, J. Khan, T. Watanabe, G. Slater, T. Kosugi, Y. Sakamoto, K. Matsuzaki, Y. Ogawara ------------------------------------------------------------------------------- 1. Solar Activity Solar activity was high, but again (like last week) short of X-flares. There were 10 M-class flares and many C-class flares. The backgound GOES flux stayed round C2 during the week. ------------------------------------------------------------------------------- 2. Standard Operations 2.1 SXT Table Uploads The following SXT tables were uploaded: JST Day UT Start Time Pass Table ID ==================================================================== Monday PM 10-Sep-2001 8:54 3 010910 P3 ARS1 STD Tuesday PM 11-Sep-2001 3:48 1 010911 P1 ARS1 DIFF Tuesday PM 11-Sep-2001 8:52 4 010911 P4 ARS1 146 Wednesday PM 12-Sep-2001 5:27 2 010912 P2 ARS1 DARK Wednesday PM 12-Sep-2001 8:50 4 010912 P4 ARS1 STD Thursday PM 13-Sep-2001 7:26 2 010913 P2 ARS0 J146 Thursday PM 13-Sep-2001 9:08 3 010913 P3 ARS0 J146 Thursday PM 13-Sep-2001 8:49 4 010913 P4 ARS1 STD Friday PM 14-Sep-2001 3:43 1 010914 P1 ARS0 J146 Friday PM 14-Sep-2001 7:16 3 010914 P3 ARS0 J146 Friday PM 14-Sep-2001 8:48 4 010914 P4 ARS1 STD Saturday PM 15-Sep-2001 2:01 1 010915 P1 ARS0 J146 Saturday PM 15-Sep-2001 7:04 4 010915 P4 ARS1 STD ==================================================================== ... a new world's record for SXT tables per week? 2.2 STT Timer Setting The STT timer was set during pass 4 (Pass ID : 010911-0618) on Tue 11-Sep-2001 (UT). Next setting due Tuesday. ------------------------------------------------------------------------------- 3. Special Operations: 3.1 OG revision DAY (#32) and NIGHT (#05) OGs were revised to use NOR and FAQ modes, respectively. The OGs were edited by Te.Watanabe-san, and they were updated at pass 1 (Pass ID : 010911-0308) on 11-Sep-2001 (UT). 3.2 FAQ operation during s/c night Recent high solar activity and decrease of the s/c altitude have resulted in increasing the Z-axis pointing error. In order to remove this pointing error, the FAQ (fine acquisition) control mode was used between pass 3, 10-Sep to pass 1, 11-Sep. In the FAQ mode, the Z-attitude control is actuated by the MTQ (magnetic torquers), not by the CMG (control moment gyros). Subsequently the DAY (37h) and NIGHT (05h) OGs were changed so that FAQ can be routinely used during the s/c night periods; during day periods, the S/C attitude control works well with the NOR mode as before. ------------------------------------------------------------------------------- 4. Errors and Problems 4.1 SXT Errors: None 4.2 DP Errors: None 4.3 BCS Errors: None 4.4 Wallops connection blackout The network connection with Wallops station was shut down following the terrorist attack which happened on September 11, 2001. The ftp connection did not work until 14-Sep. SSOC was concerned about the operation of the NASA ground stations but confirmed via the ISAS network operators (the room just below the ex-ASCA operations room) that the data were flowing normally, so apparently the operational leased line continued to operate even if Internet access to NASA was cut off. 4.5 Wallops schedule times Two versions of the w38 schedule were received, the first in error by about 4 minutes. We exchanged e-mail with Debbie Dukes about this. 4.6 OP timing Saturday The OP START command on 010915-0515 was about 45 sec late, so an OP CONTINUE was issued on 010915-0618. ------------------------------------------------------------------------------- 5. NASA Station Schedule 5.0 White Sands E-mail has been exchanged with E. Winter of White Sands and with Debbie Dukes of Wallops. White Sands is taking over the scheduling function. The system will be identically the same except for the IP number for ftp access, according to descriptions, and parallel operations have already been going on for some time. We provided White Sands with the IP number for flare20 for firewall access purposes. Question - should we have a backup IP address? Comment - we don't remember ever using this capability during the Wallops years. The e-mail link is already a backup, and the IP number could quickly be switched at ISAS if a hardware problem happened. 5.1 Contact Pass Cancellations/Additions The following schedule changes occurred: ========================================================================= Week Schedule Changes ========================================================================= Real-Time 37 0 cancellations Final 38 0 cancellations, 3 additions requested (0 granted) Preliminary 39 5 cancellations, 3 additions requested (2 granted) Strawman 40 55 cancellations ========================================================================= 5.2 Contacts this week and next (see 8.12): Week Wallops Santiago Goldstone Canberra Madrid NASA Japan 37 28 2 3 5 0 38 26 38 30 0 0 2 0 32 26 5.3 Data Transmission from NASA Ground Stations ----(Copied from /home/flare1/yohkoh/dsn_corrupt/2001/01_37)---- 241 46 2115 missing data requested 04-Sep no response requested 06-Sep corrupted requested 10-Sep Closed/ corrupted data. INTERMITTENT LOCK AT 262144BPS ON TCP1C1 AND TCP2C2. ATTEMPTED ANTENNA OPTIMIZATION AND HALTING/RESTARTING TCP'S WITHOUT IMPROVEMENT TOTAL BLOCKS FOR PASS=6770 FROM TCP1C1. 242 66 2029 missing data requested 04-Sep no response requested 06-Sep Closed/ correct data 243 46 1930 missing data requested 06-Sep Closed/ correct data 244 46 2112 missing data requested 06-Sep corrupted requested 10-Sep missing data requested 13-Sep 249 80 0108 corrupted tape requested 14-Sep 250 80 0107 missing data tape requested 14-Sep 251 80 0106 corrupted tape requested 14-Sep 253 80 0102 corrupted tape requested 14-Sep 253 80 2319 corrupted tape requested 14-Sep ***** DSN data <2001.08> ****** Total passes Acquisition rate Goldstone 6 100.00% Canberra 9 44.43% Madrid 20 98.15% Wallops 123 99.39% Santiago 2 100.00% Question: why is Canberra so bad? Answer from Seko_san: this seems to be a communications problem internal to the Wallops/DSN communications. Watanabe_san has exchanged e-mail with Debbie Dukes about this. Note: these statistics refer to August onwards; this week (37) we've had 100% from two Canberra passes, so perhaps the problem is resolved. ------------------------------------------------------------------------------ 6. KSC Pass Conflicts and Schedule : Six passes were lost to AKEBONO. : Six passes will be lost to AKEBONO. ------------------------------------------------------------------------------ 7. Hikitsugi Items 7.1 Tohbans for Next Week SSOC Tohbans : Sekii & Sakamoto KSC Tohbans : J. Kiyohara & Tamura 7.2 STT Timer Setting The STT Timer Set is due on Tuesday 18-Sep-2001 (UT). 7.3 Holiday Schedule The next holiday is Sunday 23-Sep-01 (JST). The 34m-antenna operations are scheduled for pass 2 (03:38 (UT)) and pass 5 (08:44 (UT)). These operations will be downlink only. 7.4 STT MAP operation in OP (see 8.10) Note that we have stopped the STT MAP commands and operations in the OPs. 7.5 The OP and the command sheets for today The OP and command sheets for today, Monday 17-Sep-01 (UT), have been already been checked and sent (#13) to KSC. ------------------------------------------------------------------------------ 8. Unchanged Hikitsugi Items from Previous Weeks: 8.01 DSN Pass Additions (2000-w20; modified 2001-w10) >>>>>*** DON'T FORGET TO REQUEST PASS ADDITIONS!!! ***<<<<<<< Yohkoh loses DSN passes as follows: (1) Canceled by the SSOC tohbans (2) Deleted by DSN The Tohbans SHOULD COMPARE the STRAWMAN, PRELIMINARY and FINAL schedules for each week to see if some of the passes lost by case (2) could be replaced by ones from case (1). -------------- Thus it may be possible to request pass additions for the PRELIMINARY and FINAL week schedules from the [case (1)] STRAWMAN cancellations. Only request additions from the crossed out cancellations done by SSOC. The routine to use is ADD_DSN: e.g., IDL> add_dsn, 28, /prelim IDL> add_dsn, 29, /final Decide on the complete list of passes to be added and select them like CANCEL_DSN. Then ftp and email the appropriate file. 8.02 Weekend Terminators If possible, please schedule terminator opportunities on any weekend table (i.e., if room permits). 8.03 Software Problems PR_GEV with /hc keyword produces a temporary output file but doesn't print it at the printer. 8.04 OP_FIRST_GUESS Problem (1) (1999-w38, 1999-w45) In a situation with two KSC cancellations on each of two days (a rare condition) the BDR optimization feature of OP_FIRST_GUESS crashed. After experimentation, we found that it ran OK without the final cancellation request (two the first day, but just the first one on the second day). The second one then had to be removed manually. Records of the problem were forwarded to Lemen-san, but no answer had arrived at the time of writing. (2) (1999-w46, 1999-w45) During the preparation of `991109-1238 OP', `991110-1135 OP' and `991111-1032 OP' OP_FIRST_GUESS crashed with the message "OP_START_END: problem with detection of LOS/AOS/DSN Repro events". This problem was solved by changing OP_FIRST_GUESS options: choose optimization 1 rather than 2. (3) (2001-w06) OP_FIRST_GUESS frequently got confused about start times, trying to read weekly files extending forward years from the present. Retries eventually worked. 8.05 Keeping Wallops Contacts (1999-w42, 1999-w45) This is not a new policy, but to emphasize (paraphrased from e-mail from Hugh Hudson): We should keep all valid Wallops passes, independent of day/night status, in order to maximize our Wallops use and minimize our DSN use. NASA won't give us many DSN passes anyway, so if we select a Goldstone pass in preference to a Wallops one, we'll normally just lose both. Another reason is that CANCEL_DSN software needs some repair, since it seems to replace the DSS identifier WGS with 0. This is likely to cause confusion, but of course if we don't cancel Wallops passes we won't have this problem often. 8.06 34m ANT Operation (2000-w33, 20001-w12) 34m Operation will be done only on Sunday (=Yohkoh holiday) for up to 2 or 3 passes. There will be no 34m OP to compensate for the lost pass due to the conflict with the other satellites. For further details, please ask Kosugi-san. Note that 34m operation requires more CE slots in OP table than DSN operation does. Weekend OP cannot accommodate many 34m passes without sacrificing even more DSN passes. Also, max elevation of the 34 m antenna should be checked carefully using Weekly Visible Diagram (do not trust op_first_guess nor AOSLOS listing). Try to avoid zenith passes ( Max. El. >76 degree) in planning. However, do not try to change the already fixed schedule just because the pass chosen turns out to be a zenith pass. There's no problem using the zenith pass with extra few op commands. (2001-w12) 8.07 Weekend DSN passes (2000-w49) We used to schedule 12 DSN passes during the weekend, but now we have two passes with the KSC 34m antenna. So only 9 or 10 DSN passes should be scheduled for the weekend. Please be sure to cancel extra passes as early as possible. 8.08 DSN Max Elevation DSN max elevation must be higher than the following value: Contact Max El.(degrees) ------------------------------ Madrid 10.0 (2000-w45) Santiago 13.5 (2000-w44) Wallops 6.5 (Depends on azimuth. See the map on whiteboard.) Others 7.0 8.09 OP and SXT Table Transfers Trouble (2000-w34) OP and SXT tables can not be transferred to KSC correctly when the MS computer at ISAS is in Initial Program Load(IPL). HALCA groups operate the satellite from ISAS. SSOC tohbans must be careful to transfer OP and SXT tables in the following periods, an hour before the beginning and an hour after the end of HALCA contact. As for IPL of MS computer at KSC, operators confirm if new OP and SXT tables come to MS computer at ISAS after the IPL. 8.10 STT MAP operation in OP (2000-w42, revised at 2000-w53, 2001-w08, 2001-w24) Since 2001-w25, we will stop the daily STT MAP operation in OP. 8.11 Bug-fix Report about the Attitude Determination Software (ADS) at 200-w53 Related with the Y2K problem, a software bug was found in the attitude detection software. The problem occurred in the procedure to search the orbital element file. In the program including the bug, the attitude of the Yohkoh satellite was calculated using the latest orbital elements in DASD or Sirius database, while it must be done using the elements of the day nearest to the observation date. This bug has been fixed now. This bug causes the large attitude error when the observation date and the calculation date of the attitude are largely different. From 2000 Jan. to 2000 Sep., there are 10 candidates with the attitude error greater than one minutes of arc, which are as follows (obs. date); 27-Apr-2000, 28-Apr-2000, 13-Sep-2000, 14-Sep-2000, 7-Jan-2000, 11-Sep-2000, 9-Mar-2000, 8-Jan-2000, 28-Sep-2000, 12-Sep-2000. Re-calculation of the attitude is scheduled to these 10 cases. 8.12 print_contact (2001-w07) It's helpful to see the actual statistics of the DSN/Wallops station passes. The program "PRINT_CONTACTS" does this for inclusion in the weekly report, e.g. IDL> print_contacts,[6,7] lists the passes for weeks 6 and 7. [end of report]