SSOC Tohbans' Report for Week 21 (May 24 - May 30) of 1993 1993-May-31 SSOC: Y. Suematsu, J. I. Khan KSC : K.Yoshimura, Y. Nishino 1. Solar Activity Although the Sun's activity was fairly low during week 21, it was higher than week 20. At least two M class flares were observed by Yohkoh. 2. List of SXT Table Uploads Month Day Pass ID Table Name May 25 Pass3(930525-0824) 930525 T1 P1 ARS2 DUAL ROI May 25 Pass3(930525-1031) 930525 T2 P3 ARS2 DUAL ROI May 26 Pass1(930526-0721) 930526 T1 P1 CAL + LIMB OBS May 27 Pass1(930527-0722) 930527 T1 P1 ARS1 + CCDCAL May 28 Pass1(930528-0619) 930528 T1 P1 ARS1 + LONG 3. STT Timer Set The STT timer was set during the following Pass: Month Day Pass ID May 25 Pass2(930525-0927) 4. Special Operations Month Day Operation May 24 HXT Calibration May 24 HXT Fine Gain Adjustment OGs Uploaded May 25 HXT Calibration May 26 HXT Calibration 5. Report of Errors The following errors occurred this week: Month Day Pass ID Type of Error May 28 Pass2(930528-0722) SXT BITMAP error May 28 Pass3(930528-0826) SXT BITMAP error We were informed that SXT had a BITMAP error on Friday, May 28. It was cleared by the KSC tohbans in the same pass, without problem. 6. Report of Problems The Gateway was down twice this week, including for more than 24 hours on May 25. We requested the following data from JPL which was not received because of this Gateway problem. DOY Station BOT EOT 139 M 2242 2251 140 M 0830 0842 140 G16 0350 0400 As of Saturday, May 29 we have not received the last two items. On Friday, May 28 we retrieved the DSN 7-Day Strawman Schedule Activities Listing for week 24 (14 Jun 93 - 20 Jun 93). Examining this file we found that it only included SOLA TKG PASSES for Monday, June 14. No SOLA TKG PASSES were listed for Tuesday, 15 June -- Sunday, 20 June. We informed Joseph P. Espinueva and Diem Tu of this fact by both email and fax. The Sirius data base creation was late for Passes 3 - 5 of May 27 . This was apparently caused by someone changing the KSC option to MT and forgetting to switch it back to the KSC option. This cause of this problem should be clarified. We were informed that Prof. M. Kundu did not receive gbo_mail. In connection with this and other previous cases of returned gbo_mail perhaps the KSC tohbans could inform the SSOC tohbans (by email) if there is any returned gbo_mail so we can report it and any related problems. 7. Hikitsugi Confirm the tracking schedules for June 14 - June 20. The next STT Timer Set is scheduled for Tuesday, June 1. Tohbans for week 22: SSOC: K. Ichimoto, K. Suga, KSC: Y.Nishino, K. Yaji 8. Other It was suggested that perhaps the cron jobs printing out the NOAA Region Summary Plot be stopped. It was decided after the today's meeting that these print-outs were useful and that they should be maintained. At the Monday Operations meeting Prof. Ogawara pointed out that he received information from NEC that there is an increase in the drift rate of the Y gyro. There is no problem at the moment as the drift rate is still far below the required specifications. This may have to be taken into consideration in the future. In relation to the protracted period of the ISAS Gateway being down we were informed that this was due to a special operation to do with the testing of another satellite project. This problem is not expected to arise very often in the future. Regarding the more frequent temporary problems for JPL accessing the Gateway, Yamada-san confirmed that he is the responsible person to be contacted in case of problems in the future. The SSOC tohbans should contact him as soon as JPL report a problem with the Gateway. A colleague recommended that in the future the SSOC tohbans give a very brief summary of the weeks solar activity to add an element of science to the Monday Operations meetings. One simple possibility might be to show several OHPS of full disk images of the Sun and the GOES summary plot for the week in question. --------------------------------------------------------------------------- DRAFT OBSERVING PLAN FOR OUTER CORONA May 29, 1993 H. S. Hudson With the success of the long-exposure data obtained in support of the SPARTAN mission in April, it's my feeling that sufficient tests have been done and that a regular program of coronal off-pointing by Yohkoh should be instituted. In addition to this, with the installation of the ROG off-point commands, the preparation time for Yohkoh operators has been minimized. With this memo I'm proposing that we now initiate a weekly offpoint program. This can be done during daylight passes initially, but as we gain experience I hope that it can continue regularly even during the invisible orbits. The offpoints proposed here are larger than the "limb tangent" offsets currently in the OG tables. I would like for us to go back to the 18 arc min offsets of the celebrated May 8 and July 26 images. There should be no problem with ROG's for these, since they were written and tested before. I propose one orbit E, and one orbit W, nominally on a fixed day each week (Thursday?) but with consultation each week between the tohbans and the SXT chief observer. The scientific objectives of this activity would include the following: * To observe large-scale closed coronal structures at the limit of the CCD range, to support quantitative analysis of their physics. * To obtain sensitive observations of expanding structures above active regions, both in their quiescent state and during events. * To obtain pre- and post-flare information to higher altitudes for limb flares. * To obtain better coronal range and cadence for observations of X-ray effects associated with prominence eruptions and CME's. * To generate coronal synoptic data, i.e. to follow the coronal structures on a one-week sampling interval, for an extended period of time. This is essential input for solar-wind modeling on longer time scales (many solar rotations). The "scientific cost" of doing this is quite small: a two-orbit gap in the steady pointing for the movie, once per week; and an additional scheduling problem for collaborative observations with other observatories. In addition, since the 18 arcmin offsets move the Sun partially off of the CCD area, there is some risk of loss of flare data. This risk will have to be addressed by the tohbans and the chief observer. Since we now have many flare observations, I feel that this small potential loss would be acceptable, and that the "deep corona" observations should be done as a rule. The sequence tables used for the SPARTAN offpoint is a possible model for SXT operation. This contains long exposures (30 sec in H resolution Dagwood, for example) plus many Q resolution images to monitor time variability. The longest exposures that could be tolerated during a given observation would, as usual, be determined by the SXT chief observer at the time of the table planning. I would like to convene a "table drafting committee" consisting of Bruner, Hara, myself, and whoever else would like to join in - inputs via e-mail quite welcome, of course. I suggest that we start with this activity on Thursday, June 3.