SSOC Tohban Report for Week 32 (31-Jul-2000 to 6-Aug-2000) SSOC: K. Akita, A. Takeda KSC: H.Ishizaki, T. Koyama 0. Meeting Attendees Fletcher, Khan, Kano, Kosugi, Matuzaki, Miyagoshi, Nagata, Nakakubo, Ogawara, and Takeda ----------------------------------------------------------------------------- 1. Solar Activity Solar activity has been lower this week. GOES background was sub C level, and the Sun produced only several C class flares. ----------------------------------------------------------------------------- 2. Standard Operations 2.1 SXT Table Uploads The following SXT tables were uploaded: ====================================================================== JST Day UT Start Time Pass Table ID ====================================================================== Tuesday AM 31-JUL-00 15:09 4 000731 P4 ARS1 STD* Tuesday PM 01-AUG-00 10:09 1 000801 P1 ARS1 RAPID Wednesday AM 01-AUG-00 15:07 4 000801 P4 ARS1 DIFF* Wednesday PM 02-AUG-00 11:59 3 000802 P3 ARS1 DARK Thursday PM 03-AUG-00 08:42 1 000803 P1 ARS1 RAPID Friday PM 04-AUG-00 10:32 3 000804 P3 ARS1 RAPID Saturday PM 05-AUG-00 12:22 4 000805 P4 ARS1 STD ====================================================================== 2.2 STT Timer setting The STT timer was set during Pass 3 on Tuesday, 01-AUG-00 JST (Pass ID: 000801-0928). ----------------------------------------------------------------------------- 3. Special Operations None ----------------------------------------------------------------------------- 4. Errors and Problems 4.1 SXT Errors An SXT bit map error was found at Pass 2 on Wednesday, 2-Aug-00 JST (ID: 000802-0721). It was recovered successfully in that pass. 4.2 BCS Errors A BCS error (MEM CHECKSUM ERR) was found at Pass 5 on Wednesday, 2-Aug-00 JST (ID: 000802-1031). It was recovered successfully in that pass. 4.3 Wrong universal time in some KSC repro data in SIRIUS The situation still continued this week (even worse?). NEC people reported they found 10 or more incorrectly time-stamped data (8 secs long). (See item 4.4 of the tohban report for week 31. ) 4.4 34m antenna operation (1) Zenith pass criterion A part of repro data was lost in the zenith pass on Tuesday (pass ID: 000801-0824), because SSOC tohbans had not prepared a zenith-pass OP. We failed to recognize it as a zenith pass, as the max. elev. shown in the AOSLOS list from the mainframe computer was 78 deg. We should have used the value in the Weekly Visible Diagram instead (80.1 degree for this pass). It is somewhat misleading that we have to fill in "34m antenna OP sheet" with max. elev. in the AOSLOS list. On the other hand, Watanabe-san pointed out that 34m zenith pass criterion ought to be 75 degrees, rather than 80 degrees, and that he sent us an instruction to Tohbans a while ago. We found his email of June 8 (week 24) which says the above and also says 'try to avoid zenith passes'. We wonder why these are not mentioned in the tohban manual for 34m operation. (2) Shortage of down-link time BDR REC started before finishing down-link in the first pass on Friday ( Pass ID: 000804-0515, max. elev.=11 deg!). Almost one fifth of the repro data was lost due to this. The manual says the timing of BDR REC should be set at the timiming of elev.=10 degree. We could have delayed the timing of BDR REC so as not to truncate the data( more than 5 min. interval between KSC REPRO and BDR REC)? If so, it should be added to the tohban manual. (3) Tracking was lost after zenith pass op 34m ANT operator reported that it could not detect X-band signal properly for about one minute right after the zenith pass operation on Saturday (Pass ID: 000805-0722). They managed to keep on tracking the satellite with the side-lobe signal,though. However, the signal level was too low to capture the complete repro data. Surely, we'd better avoid a zenith pass... ----------------------------------------------------------------------------- 5. NASA Station Scheduling 5.1 Contact Pass Cancellations/Additions The following schedule changes occurred and/or requested: =========================================================================== DSN/NASA Week Schedule Changes =========================================================================== Final 32 0 additions; 3 cancellations by SSOC Final 33 0 additions 0 cancellations Forecast 34 2 additions; 0 cancellations by SSOC Strawman 35 62 cancellations (Seko: 2, SSOC: 60) =========================================================================== 5.2 Data Transmission from NASA Ground Stations ----(Copied from /home/flare1/yohkoh/dsn_corrupt/2000/00_32)---- 207 82 0628 corrupted tape requested 31-Jul Closed / correct data 209 80 0501 corrupted tape requested 01-Aug Closed/ correct data 211 76 0516 corrupted tape requested 01-Aug Closed/ same data 213 16 0704 lacking data requested 02-Aug ----------------------------------------------------------------------------- 6. KSC Pass Conflicts and Schedule - Yohkoh lost 10 20-m passes (6 to HALCA, 4 to ASCA). - There were 11 passes (down-link only) with the 34m. - Yohkoh will lose 6 passes (1 to HALCA, 5 to ASCA). - There will be 2 down-link-only passes on Sunday. ----------------------------------------------------------------------------- 7. Hikitsugi Items 7.1 Tohbans for Next Week SSOC: T. Miyagoshi, K. Nakakubo KSC: T. Koyama, M. Hata 7.2 STT Timer Setting The next STT TIMER SET is due on 8-Aug-2000 (Tuesday) UT. 7.3 BCS Calibration BCS Cal is scheduled on Tuesday. 7.4 Holiday Schedule The next satellite holiday will be 13-Aug, Sunday JST. 7.5 OP OP and command sheets for Monday (7-Aug-2000) were prepared and were sent to KSC. 7.6 34m ANT Operation 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. Maybe, a couple of other items should be added to the operation manual ( see 4.4 ). ---------------------------------------------------------------------------- 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 (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. 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 OP_FIRST_GUESS Problem (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. 8.6 DSN Pass Additions (2000-w20) *** Don't forget to request pass additions! *** Yohkoh loses DSN passes as follows: (1) Canceled due to conflicts with ASCA (by Seko-san) (2) Canceled because Santiago is unavailable (3) Canceled by the SSOC tohbans (4) 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 cancelations). 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. 8.7 OP Sequence for KSC Operation Using 34 m Antenna (2000-w24) KSC downlink operation with 34 m antenna has started since the end of May 2000. Since we cannot send any command to Yohkoh with 34 m antenna, the downlink operation is conducted with OP commands. ----------------------------------------------------------------------------- === END ===