REPORT FROM ISAS   11/14/91
L. Acton

Yohkoh data from NASA's Deep Space Network (DSN) is beginning to flow in
quantity! Yesterday we got, for the first time, fairly uniform time
coverage of full disk images over 24 hours.  Wonderful things appeared!
In the north around the polar crown a tremendous arcade of loops with
footpoints separated by about 1/3 of a solar diameter appeared over a
period of a few hours over a longitude range spanning maybe 120 degrees. 
We also observed a pair of small (10 arcsec) loops flaring in
synchronism at 11/12/91 1740 UT (AR 6908?) which were separated by 70
arcsec.  There was no apparent connection between the sites in x-rays. 
Finally, the westernmost spot of AR 6908 produced the most amazing
searchlight beam in x-rays at around 1100 UT. 

Operating with DSN coverage is still a massive task for the Yohkoh duty
scentist.  A list of requested station contacts must be sent to JPL 4
weeks in advance.  Thanks to hard work by Jim Lemen and others the AOS
and LOS times from the ISAS mainframe are now accessible to our
workstations for processing to generate the proposed contact list and
Jim has prepared an IDL program for this purpose.  However, the orbital
predictions at present are not good enough to select stations 4 weeks in
advance.  This week Stephen Wolf and Leonard Efron of JPL/DSN and other
NASA people were at ISAS to discuss DSN usage.  A productive meeting was
held and we hope that the remaining problems can be fixed.  From a
scientific point of view, the DSN coverage is a tremendous boost to the
quality of SXT coverage.  Many thanks to all within NASA and ISAS who
have worked hard to make this possible. 

Yesterday we dedicated one revolution to obtaining a continuous movie
with 8 sec time resolution and full angular resolution (5.22 arcmin
FOV).  The automatically selected target was again AR 6908.  The movie
is perfectly exposed and shows one tiny and one large loop brightening
over the interval but nothing dramatic.  This movie will be the fodder
for some careful analysis before we repeat the experiment.  Following
the movie we changed the SXT partial frame image sequence table to
cycle through all filters for temperature analysis of active regions. 
This experiment was proposed by Hiro Hara, one of Dr.  Tsuneta's
graduate students. 

Truly remarkable progress is being made by Sam, Mons, Jim, Gary, Greg
and Fei Mei on analysis software.  It is impressive to observe the
careful coordination and communication to assure software control and
compatibility within the myriad of modules that address the reformatted
data.  Given the tremendous inhomogeniety of the SXT data stream it is
truly wonderful to be able to extract what is desired so quickly.  I
encourage SXT team members to step up to the challenge of learning to
use the power of these tools.  The delivery of image registration
modules has been unfortunately delayed because the processed Yohkoh
pointing information is still not available in the Sirius data base. 
This problem with attitude information is also the reason for the very
long delay in shipment of the first reformatted data tapes.  In the
meantime, co-i's are getting bits and pieces of data over the network.

The aspect sensor continues to go dim at the previous rate.  All other
SXT functions are nominal.