SSOC Tohban Report for Week 50 
                       (13 December - 19 December 1993)

                                         M. Shoji, T. Kosugi (SSOC)
                                         H. Watanabe, K. Yaji (KSC)

1. Solar Activity

  The solar activity is quite low, but there may be a signature of increasing
 at weekend.  A long-duration flare, C3 class, occurred on ~20:00 UT on 17-th.  

2. Standard Operations

 2.1 SXT Table Uploads:

      JST      pass    (UT)
  (Wed) 15-Dec  #4  "931213 T1 P4 ARS1 DKCAL" ... table name (date) is wrong
  (Wed) 15-Dec  #2  "931215 T1 P2 DEEP CORONA"
                #4  "931215 T2 P4 ARS1 STD" ... mistake in the long exposure
  (Thu) 16-Dec  #2  "931216 T1 P2 ARS1 STD"
  (Sat) 18-Dec  #2  "931218 T1 P2 ARS1 STD" ... delete long exposure
  
 2.2 STT Timer Set

  The STT timer was set on Monday, 13 December, at the 2-nd pass.  The next
 STT timer set should be done on Monday, 20 December.

 2.3 Weekly Offset Pointing

  The 8' deep corona offpoint observations were performed on Wednesday, 15-Dec.
       Pass2 : S/C offpoint E(8') , Pass3 : S/C Offpoint W(8'), 
       Pass4 : S/C normal point 

3. Special operation

 3.1 Terminator images with S/C offset

  On Saturday, 18 December, a trial was made for terminator image acquisition
 between passes #2 and #3 with S/C south-offpointed by 16' using OP.

 3.2 HXT Gain Calibration and Gain Adjustment

  Calibration     ... pass #5 on Tuesday, 14 December
                      pass #5 on Wednesday, 15 December
  Gain Adjustment ... pass #1 on Friday, 17 December
  Calibration     ... pass #5 on Friday, 17 December

4. DSN communications

  No troubles at all.  We received the inquiry result as follows:

  New-year holiday plan was fixed.  We carefully selected DSN passes during
 the holidays, with writing a "strawman" OP (stored in OPOGEDT, also printout
 is available in the operation room), and informed the selected DSN passes to 
 JPL (see e-mail to Wendell Keller, attached).

 (from W49 report) "DSN data (DSS16 DOY336(02-Dec-93) 1421-1431) have not
 yet arrived" ... (reply from Wendell Keller) "the pass was cancelled due to
 the Shuttle support"

5.  Problems, Errors, etc

 5.1  20-m antenna trouble

  Due to a trouble of the 20-m antenna control system at KSC, the 1-st pass
 on Tuesday, 14 December, was cancelled.  The cause of the trouble was in the
 interface between the control desk and the antenna driver.  The two components
 were reset.

 5.2  A-400 system down

  Due to a trouble of the A-400 computer at KSC, no (real-time) data transfer 
 from KSC to SSOC were possible on Friday, 16 December.  At the time of this
 report writing (Saturday, 17:45 JST), the data have not yet arrived.

 5.3  SXT bit map error

  found at pass #2 on Tuesday, 14 December ...  cleared by "YOBI commands C"

 5.4  False flares in SAA

  Two false flares were observed on Thursday in the playbacked data at passes 
 #2 and #3.  Examination of recent data has suggested that it is appropriate
 to slightly shift the predicted SAA location towards west by about 3 min of
 Yohkoh orbital motion.  T. Kosugi asked Jim Lemen to revise the corresponding
 op_first_guess parameters (Saturday, 18 December).

6 . Hikitsugi
 
 6.1 Week 51 Tohbans:   SSOC:   A. Takeda, Nishino
                        KSC :   K. Yaji (+ H. Watanaabe)

 6.2 The STT timer set ... Monday, 20 December (already included in the plan)


EOF