SSOC Tohban Report for Week 16 (16-Apr-2001 to 22-Apr-2001) SSOC Tohbans : T.Miyagoshi,H.Ishizaki KSC Tohbans : H.Isobe,H.Kozu 0. Meeting Attendees T.Kosugi, J.Khan, K.Yoshimura, S.Nagata, K.Matsuzaki, A.Takeda, H.Ishizaki. ------------------------------------------------------------------------------- 1. Solar Activity The solar activity level was high last week. There occurred four M-class flares as listed below. date max.time X-ray/optical NOAA region Apr 16 06:16 M1.1/- (unknown) Apr 17 21:18 M1.3/- (unknown) Apr 19 11:22 M2.0/- (unknown) Apr 20 05:11 M1.0/- (unknown) (from Hiraiso report and NOAA Weather Wire Service http://www.sec.noaa.gov/Data/wwire_tab.html) ------------------------------------------------------------------------------- 2. Standard Operations 2.1 SXT Table Uploads The following SXT tables were uploaded: JST Day UT Start Time Pass Table ID =========================================================== Monday 16-APR-01 05:31 2 010416 P2 ARS1 STD W Tuesday 17-APR-01 03:52 3 010417 P3 ARS1 STD W Wednesday 18-APR-01 03:52 1 010418 P1 ARS0 DRK W PFFI Wednesday 18-APR-01 07:15 3 010418 P3 ARS1 W DIFF Thursday 19-APR-01 07:15 3 010419 P3 ARS1 STD W Friday 20-APR-01 03:53 2 010420 P2 ARS1 STD W Saturday 21-APR-01 05:35 3 010421 P3 ARS1 STD W =========================================================== 2.2 STT Timer Setting The STT timer set was done during pass 2 (Pass ID : 010420-0308) on Friday, 20-Apr-2001 (UT). ------------------------------------------------------------------------------- 3. Special Operations 3.1 STT re-tracking of Canopus The Canopus eclipse period ended on Thursday, 19-Apr and a series of STT-MAP operations were carried out, which revealed that the total shift of s/c attitude around the Z-axis amounted to +2.68deg. A SET-ADS command to move the target area was issued at 010419-0618. Another STT-MAP data was successfully taken on 20-Apr at 010420-0205, which showed that further +1.2deg movement was necessary. The total attitude shift was +3.88deg in 141 hours during 14-20th of April. At 010420-0308, STT timer was set as scheduled and another SET-ADS command for this 1.2deg shift was also uploaded. At 010420-0412 and 010420-0515, STT-TRK data were monitored and we confirmed that Canopus was tracked in the STT target area properly and that ACP started revising the Z-gyro drift rate in these passes. >From these operations and telemetried data, we found that the trend of the Z-axis drift rate during the eclipse period was as we had expected before the eclipse. (by TW) ------------------------------------------------------------------------------- 4. Errors and Problems 4.1 SXT Errors Bit-map error was found at pass 1: 010420-0215 (20 Apr) and recovered by Yobi-C command in the same pass. 4.2 DP Errors None. 4.3 BCS Errors BCS error was found at pass 1: 010420-0215 (20 Apr) and recovered by next pass (pass 2:010420-0308). ------------------------------------------------------------------------------- 5. NASA Station Schedule 5.1 Contact Pass Cancellations/Additions The following schedule changes occurred: =================================================== Week Schedule Changes =================================================== Real-Time 16 9 cancellations Final 17 0 cancellation Preliminary 18 33 cancellation Strawman 19 32 cancellations =================================================== 5.2 Contacts this week and next (see 8.12): Week Wallops Santiago Goldstone Canberra Madrid NASA Japan 16 22 2 3 9 0 36 26 17 30 0 1 0 0 31 28 5.3 Data Transmission from NASA Ground Stations ----(Copied from /home/flare1/yohkoh/dsn_corrupt/2001/01_16)---- 094 76 0411 corrupted tape requested 13-Apr Closed/ same data 096 74 1617 corrupted tape requested 13-Apr Closed / correct data 097 74 1618 corrupted tape requested 13-Apr Closed / correct data 099 66 1826 missing data requested 18-Apr Closed/ same data UNABLE TO PROCESS ANY TLM. POOR DOWNLINK SIGNAL LEVEL RECEIVED AS OBSERVED IN BOTH MFR'S. VERIFIED PROPER CONFIG AND SETUP. 099 66 2007 missing data requested 18-Apr Closed / same data UNABLE TO PROCESS ANY TLM. SIGNAL LEVEL BELOW TLM THRESHOLD. PROBLEM FOUND TO BE BAD PREDICTS. VERIFIED PREDICTS BIAS BY -8SEC., ANTENNA ANGLES BY 0.1 DEGREE. 099 66 2148 missing data requested 18-Apr Closed/ same data 4161 blocks missing. Blocks sent : 14335 BOT at 214800, RCV in lock at 215025. AGC at AOS lower than normal. suspected side lobe acquisition. 101 16 0410 missing data requested 18-Apr Closed/ same data COULD NOT ACQUIRE A STRONG DOWNLINK. SUSPECT A PREDICT TIME BIAS OR OFFSET. ENTERED TIME BIAS IN BOTH DIRECTION, BUT SIGNAL LEVELS WERE CHARACTERISTIC OF A SIDELOBE TRACK. 101 16 0552 missing data requested 18-Apr Closed/ same data OPSCHIEF REPORTED POSTPASS A LOW BLOCK COUNT OF 15780 BLOCKS WAS CAPTURED ON THE CDR. THERE WAS NO INDICATION OF ANY PROBLEM WITH THIS SUPPORT. RCVR'S WERE IN LOCK FROM 055255-060227Z WITH TCP1 IN LOCK FROM 055444-055932Z. TIME BIAS FOR THIS SUPPORT WAS -2 SECONDS. REASON UNKNOWN. 100 80 0418 corrupted tape requested 18-Apr Closed / same data 102 80 0057 corrupted tape requested 18-Apr Closed / same data 102 80 0239 corrupted tape requested 18-Apr Closed / same data 103 80 0240 corrupted tape requested 18-Apr Closed / same data 104 80 1957 corrupted tape requested 18-Apr Closed / same data 104 80 2138 corrupted tape requested 18-Apr Closed / same data 104 82 2319 corrupted tape requested 18-Apr Closed / same data 105 80 1957 corrupted tape requested 18-Apr Closed / same data 105 80 2320 corrupted tape requested 18-Apr Closed / same data 099 80 2314 corrupted tape requested 20-Apr 106 80 0102 corrupted tape requested 20-Apr 106 82 1959 corrupted tape requested 20-Apr 106 80 2140 corrupted tape requested 20-Apr 106 80 2321 corrupted tape requested 20-Apr 107 82 1959 corrupted tape requested 20-Apr 107 80 2140 corrupted tape requested 20-Apr 107 80 2322 corrupted tape requested 20-Apr ------------------------------------------------------------------------------ 6. KSC Pass Conflicts and Schedule Yohkoh lost 6 passes due to conflicts with Akebono. Yohkoh will lose 4 passes due to conflicts with Halka(3 passes) and Akebono(1 pass). ------------------------------------------------------------------------------ 7. Hikitsugi Items 7.1 Tohbans for Next Week SSOC Tohbans : S.Nagata KSC Tohabns : M.Hagino, H.Kozu 7.2 STT Timer Setting The STT Timer Setting will be due on Tuesday, 24-Apr-2001 (JST). 7.3 Please continue to take STT MAP every day (see 8.10). 7.4 Holiday Schedule (KSC 34m antenna TEL: 0994-67-3152) The next holiday is 29-Apr-2001 (JST). The 34m-anntena operation is scheduled for Pass 2 (09:35-09:49 JST) and Pass 4 (12:59-13:12 JST). 7.5 OP preparation and OP Start time Please use the latest orbit data in creating OP. Because of high solar activity, YOHKOH orbit changes quickly. If KSC Toban finds large time difference between the predicted and actual event time (10 deg. elevation, max elevation, etc.; ask KSC antenna staff which is better), please report SSOC and try to reflect the time difference to the OP START time. ------------------------------------------------------------------------------ 8. Unchanged Hikitsugi Items from Previous Weeks: 8.1 Weekend Terminators If possible, please schedule terminator opportunities on any weekend table (i.e., if room permits). 8.2 Software Problems PR_GEV with /hc keyword produces a temporary output file but does not print it at the printer. 8.3 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. Re-tries eventually worked. 8.4 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. 8.5 DSN Pass Additions (2000-w20; modified 2001-w10) *** Don't forget to request pass additions! *** Yohkoh loses DSN passes as follows: (1) Canceled because Santiago is unavailable (Actually it is now available until end of 2000) (2) Canceled by the SSOC tohbans (3) 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 (4) could be replaced by ones from case (3). This means it may be possible to request pass additions for the PRELIMINARY and FINAL week schedules from the (case (3)) STRAWMAN cancellations. (The cancellations by Seko will generally be marked in red ink, and those by SSOC by pencil: Only request additions from the penciled cancellations). The routine to use is ADD_DSN: e.g., IDL> ADD_DSN, 28, /prelim and 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. 8.6 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 accomodate 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) 8.7 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. 8.8 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 Others 7.0 8.9 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). ASCA and HALCA groups operate the satellite from ISAS. We must not transfer OP and SXT tables in the following periods: "An hour before the beginning of HALCA/ASCA contact 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) If possible, please schedule the STT MAP operation just before the 1st KSC Pass on next day. The OP commands to be insrted in OP are as follows; OG-030(DEC) CMPN OBS ON OG-035(DEC) STT EVENT OFF ; 1 step after CMPN OBS ON OG-117(DEC) STT MAP START ; 1 step after STT EVENT OFF OG-118(DEC) STT MAP END ; 5 min (10steps) after STT MAP START OG-036(DEC) STT EVENT ON ; 1 step after STT MAP END OG-031(DEC) CMPN OBS OFF ; 1 step after STT EVENT ON Plese insert these command manually in OP schedule. The timing of these commands must be assigned around the mid-time of Canopus tracking window (note that the Canopus tracking does not work normally in this window). It is prefer that the command work during the night period of the satellite. The Canopus tracking window appears on the AOSLOSGD plots as a dotted line. It is preferable to schedule the 10 steps contiguously (as shown, avoiding mode switches). 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 occured 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 Serius database, while it must be done using the elements of the day nearest to the observation date. This buf 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]