Page 1 PROGRESS REPORT THE SOLAR-A SOFT X-RAY TELESCOPE (SXT) PROGRAM (CONTRACT NAS8-40801) (for February 1997) OVERVIEW The YOHKOH Mission is a program of the Japanese Institute of Space and Astronautical Science (ISAS) with collaboration by the U. S. National Aeronautics and Space Administration and the U. K. Science and Engineering Research Council. The YOHKOH satellite was launched on 30 August 1991 from Kagoshima Space Center (KSC) in Japan. The purpose of this mission is to study high energy phenomena in solar flares and the Sun's corona. Under an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation using the Soft X-ray Telescope (SXT), one of the primary experiments of the mission. The SXT was developed at the Lockheed Palo Alto Research Laboratory in cooperation with the National Astronomical Observatory of Japan, and the Institute for Astronomy of the University of Tokyo. MAJOR PROGRAMMATIC ACTIVITIES IN THE MONTH Our effort continues to ensure SXT operations in FY 98. At this time it looks relatively favorable for this to occur and we are preparing budgets for the operations extension. We are also assembling materials for the Senior Review which will take place later this summer. << Solar Activity >> The solar activity remains low, but towards the at the end of the month there were two high-lattitude regions, presumably, associated with the new cycle. There were several C-class flares during this period, but most occurred during Yohkoh's orbit night. There was an interplanetary type II on Feb 6, 1997 with an estimated solar initiation around 8 UT on Feb 4, 1997 which is probably associated with a filament eruption that occurred in the south east. << Campaigns >> There were two campaigns during this month: one day was spent in ARS0 (fixed SXT pointing) looking at a filament at south central meridian, for which SOHO CDS and SUMER could also observe; and two days were spent looking at the ingress and egress trajectories of NEAR. Richard Woo of JPL is using NEAR's telemetry signals for IPS observations of the corona down to maybe 1.2 solar radii. The SXT definition of the coronal structures is an important part of interpreting the scintillations. Woo Page 2 was fortunate to have had some activity on the right limb during the NEAR egress, so he will have both quiet Sun and active Sun in the records. For Yohkoh operations, there is a text file accessible on the Web at http://www.space.lockheed.com/SXT/html2/First_Light.html which also lists the current SXT Chief Observer, or the Unix command: # finger campaign@isass0.solar.isas.ac.jp | more The SOHO target planning is available from: http://sohowww.nascom.nasa.gov/operations/targets/today << Science >> David Alexander attended the Whole Sun Month Workshop which was a two day workshop held at Goddard Space Flight Center. The Yohkoh component of this workshop will be to provide detailed temperature and emission measure maps of the quiet sun corona. Two abstracts have been submitted to the Spring AGU in collaboration with Bagenal and Burkepile at HAO and Gibson and Thompson at GSFC. Alexander has completed the final draft of a non-thermal line broadening paper which has been submitted to ApJ Letters and he and Tom Metcalf have revised their HXT Pixon paper. Nariaki Nitta was at ISAS during the first two weeks in February and during this time he was the Chief Observer. He worked with N. Gopalswamy (U. of Maryland) and R. Schwartz (GSFC), who also were visiting ISAS, on eruptive events, comparing SXT, HXT and Nobeyama data. Nitta also continued to work with M. Kundu on X-ray ejecta and metric bursts and one paper on two-sided jets was submitted to Solar Physics. Finally, Nitta analyzed SXT CME data in preparation for the first SOHO- Yohkoh workshop which is scheduled for March at GSFC. Tom Metcalf spent the majority of the month at ISAS. While at ISAS he worked on improvements to the PIXON software. James Lemen arrived at ISAS in the middle of the month and will spend about 4 weeks at ISAS. During their overlap, Metcalf studied SXT Chief Observer duites with Lemen. Serge Savy visited Lockheed for two weeks and presented results about the Neupert effect as studied with Yohkoh flare data. He is working on the analysis of observations of flare ejecta for the upcoming IAU in France and continues to work on a preflares paper with Franta Farnik (Czech Republic). Jean-Pierre Wuelser wrote a draft of the polar plumes paper, reporting on the Mees Imaging Vector Magnetograph observations of the 7 March 1996 polar plumes campaign. It will go through another iteration with co-author Don Mickey, before submission to ApJ. During the last week of February, Wuelser served as Mees Duty Scientist. The sun was rather quiet, and severe weather at Mees allowed observations only at the end of the week. Nevertheless, the Imaging Vector Magnetograph continued to provide fine observations of the new cycle regions. Greg Slater was in Japan for the entire month. He was able to get the data reformatting caught up before heading to Mongolia with his brother Page 3 Dave to observe the solar eclipse on 9 March 1997. Sam Freeland made a two-week visit to ISAS to integrate the Yohkoh and SOHO software systems. The SOHO software tree (SSW) is now being mirrored to ISAS from Goddard, and the Yohkoh software tree is being mirrored in the opposite direction. Some of the software in the two systems had to be made compatible before this could be accomplished. The entire system appears to be working very well. Gary Linford made good progress during the month to implement our CD ROM juke box server in Palo Alto. The system is currently serving about 75 disks. On line are sfd files (the standard Yohkoh movie files) for 1991-1994, the white light movie for 1991-1992, and the flare database that was generated in Japan. Linford is currently creating CD-ROMs with the complete weekly data bases. A problem with data compression arose earlier this year when it was discovered the Unisys may seek compensation for use of its LZW compression algorithm, which is the standard used in GIF files. We had planned to use LZW to compress the data written to CD-ROM, but this is now being reconsidered. << Papers >> Submitted: "Relative timing of non-thermal line broadening and hard X-ray emission in solar flares" Alexander, Harra-Murnion, Khan and Matthews, to ApJ Letters. "A spectral analysis of the Masuda flare using HXT Pixon reconstruction", Alexander and Metcalf, to ApJ. << Public Use of SXT Images >> We are continuing to make Yohkoh/SXT images available for a variety of uses. Efforts continue to make selected images available on the Lockheed SXT WWW homepage (http://www.space.lockheed.com/SXT/). We receive requests for the Yohkoh posters (#2 and #3) by way of the form on the SXT homepage. Currently we receive requests via our homepage at the rate of 2 or 3 per day. The WEB access statistics in February were 58826 accesses and 1818 Mbytes transferred, up about 30% from January. About 100 copies of the new movie have already been distributed and it is expected that another 100 copies will be distributed in the coming months. << Yohkoh Operations and Health >> Yohkoh and the SXT continue to function very well. There has been no further increase in stray light since 25 August 1996. The quiet patrol image has been changed to Al/Mg (DPE=17) to try to improve the performance of the active region selection algorithm for times when the Sun is very quiet. Page 4 SXT experienced a normal level of Single Event Upset (SEU) events during the month: SXT SEU error 5-Feb-97 Pass 4: 970205-1548 recovered in pass 1 on 6-Feb-97 (-1134) SXT bit map error 10-Feb-97 Pass 2: 970210-1133 recovered in the same pass. SXT bit map error 17-Feb-97 Pass 1: 970217-0824 recovered in the same pass. SXT bit map error 19-Feb-97 Pass 1: 970219-0722 recovered in the same pass. The Japanese satellite Muses-B (later renamed to HALCA) was successfully launched on 12 February. Several Yohkoh KSC contacts were yielded to HALCA during the early check-out phase. Currently Yohkoh must negotiate its use of the KSC facility with ASCA, Akebono, and now HALCA. James Lemen has been at ISAS during the past month and during his visit he has updated the op_first_guess software that is used to plan the Yohkoh spacecraft table uploads. Some improvements were made to optimize the use of the spacecraft Bubble Data Recorder (BDR). In addition, changes were made to improve the circumstances by which terminator images are acquired. The terminator image data base recently was brought up to date, however, this required approximately six months of scheduling various terminator exposures. The recent software modifications are designed to improve this situation. Page 5 << Data Flow >> ------------------------------------------------------------------------------ Month Full Frame Images Observing Region Images Received Lost Received Lost Loss % QT FL Tot Thru Nov-94 259514 113350 1119487 328775 1448262 563313 27.66 Dec-94 6429 2456 26763 2583 29346 11904 28.86 Jan-95 6870 2349 26103 1699 27802 10211 26.86 Feb-95 6556 2545 23635 3825 27460 10111 26.91 Mar-95 5915 2082 21485 3448 24933 8485 25.39 Apr-95 6244 2266 22946 4493 27439 9688 26.09 May-95 7084 2884 29617 2647 32264 15331 32.21 Jun-95 7210 3087 25251 307 25558 12045 32.03 Jul-95 6418 4145 21180 1639 22819 15109 39.84 Aug-95 7683 2597 26115 2181 28296 10537 27.13 Sep-95 6546 2853 22006 1753 23759 10433 30.51 Oct-95 6937 3502 22177 3853 26030 13044 33.38 Nov-95 5745 2944 21252 517 21769 12119 35.76 Dec-95 6163 2615 24059 901 24960 11652 31.83 Jan-96 6474 2530 27015 1708 28723 14151 33.01 Feb-96 6200 2581 21380 890 22270 10773 32.60 Mar-96 6908 2869 25437 1460 26897 12274 31.33 Apr-96 7172 2124 45445 671 46116 18848 29.01 May-96 6925 2426 30272 1089 31361 12367 28.28 Jun-96 7522 2716 31984 1536 33520 14489 30.18 Jul-96 5954 1995 29886 4769 34655 12427 26.39 Aug-96 7214 3010 21187 1607 22794 9887 30.25 Sep-96 6904 2618 29906 303 30209 12663 29.54 Oct-96 7405 2853 16463 1842 18305 8034 30.50 Nov-96 7001 2296 24292 5395 29687 9340 23.93 Dec-96 7144 2643 25331 2087 27418 10412 27.52 Jan-97 5725 2278 17314 1257 18571 8305 30.90 Feb-97 0 0 0 0 0 0 0.00 Mar-97 0 0 0 0 0 0 0.00 Total 433862 182614 1777988 383235 2161223 867952 28.65 Number of Full Frame Images Received: 433862 Number of Observing Region Images Received: 2161223 Total: 2595085 Approximate Number of Shutter Moves/CCD Readouts: 4551702 NOTES: * The loss of images is mainly due to BDR overwrites, but there are also occasional DSN dumps which are lost. * It is common to have observing regions which contain more than 64 lines, which requires multiple exposures to make a single observing region image. This is why the number of shutter moves is larger than the number of images received plus those lost. Page 6 << Engineering Summary Table >> -------------------------------------------------------------------------------- Month Avg Dark Level # of Dark Spikes CCD Warmings Front Optical (DN) (e/sec) Over 48 Over 64 High / # Support Trans Temp /Days Temp (%) Dec-94 47.82 649.1 74246 4917 21.5 N/A Jan-95 48.55 676.7 89758 5457 20.0 N/A Feb-95 48.70 682.1 92457 5781 25.2 / 3 20.5 N/A Mar-95 48.35 668.9 85527 5271 19.4 N/A Apr-95 48.72 682.8 93904 5627 19.1 N/A May-95 48.73 683.4 94000 5820 18.8 N/A Jun-95 49.08 696.3 100780 6281 19.6 N/A Jul-95 49.34 706.2 106408 6628 18.1 N/A Aug-95 49.72 720.4 114414 7101 19.5 N/A Sep-95 49.79 723.1 115165 7222 19.6 N/A Oct-95 50.29 741.9 126452 7911 20.2 N/A Nov-95 50.11 735.1 122163 7814 25.2 / 2 20.3 N/A Dec-95 50.19 737.9 123705 7927 22.6 N/A Jan-96 50.81 761.3 136197 8888 21.5 N/A Feb-96 50.67 755.8 133263 8705 22.5 / 2 21.5 N/A Mar-96 50.85 762.9 136982 8973 20.3 N/A Apr-96 51.14 773.6 142250 9500 19.9 N/A May-96 51.16 774.4 140697 10018 19.1 N/A Jun-96 51.56 789.2 147705 10634 20.7 N/A Jul-96 57.45 1010.2 146293 12228 19.8 N/A Aug-96 52.58 827.5 165676 12393 19.6 N/A Sep-96 52.47 823.3 162784 12350 20.0 N/A Oct-96 52.21 813.8 157689 12047 22.5 / 2 21.3 N/A Nov-96 52.45 822.9 161683 12534 21.9 N/A Dec-96 53.08 846.2 171224 13860 22.9 N/A Jan-97 52.54 826.0 167533 11794 23.8 / 7 23.4 N/A Feb-97 N/A N/A N/A N/A 0.0 N/A Mar-97 N/A N/A N/A N/A 0.0 N/A NOTES: * The dark current calculations are using full half resolution 2.668 sec images not taken in during the SAA. The dark current rate assumes a "fat zero" of 30.5 DN and a gain of 100 e/DN. * The entrance filter failure of 13-Nov-92 eliminated the capability of taking optical images, so the optical transmission is not available after Nov-92. It also caused an increase in the dark current signal, however some of the increase shown here is an increase in the readout noise and is not a function of exposure duration. Page 7 << Personnel Travel >> SXT Foreign Travel between 1-FEB-97 and 28-FEB-97 FREELAND 3-FEB-97 14-FEB-97 12 (total of 12 days) HUDSON 1-FEB-97 * 27-FEB-97 27 (total of 27 days) LEMEN 17-FEB-97 28-FEB-97 * 12 (total of 12 days) METCALF 10-FEB-97 28-FEB-97 * 19 (total of 19 days) NITTA 1-FEB-97 * 16-FEB-97 16 (total of 16 days) SAVY 1-FEB-97 * 4-FEB-97 4 18-FEB-97 28-FEB-97 * 11 (total of 15 days) SLATER 1-FEB-97 * 28-FEB-97 28 (total of 28 days) ---------------------------------------------------------------- Grand Total of 129 days for 7 people NOTE: The "*" signifies travel that actually ends after 28-FEB-97 SXT Foreign Travel between 1-MAR-97 and 31-MAR-97 ACTON 13-MAR-97 31-MAR-97 * 19 (total of 19 days) HUDSON 16-MAR-97 19-MAR-97 4 31-MAR-97 31-MAR-97 * 1 (total of 5 days) LEMEN 1-MAR-97 * 14-MAR-97 14 (total of 14 days) METCALF 1-MAR-97 * 7-MAR-97 7 (total of 7 days) SAVY 1-MAR-97 * 31-MAR-97 * 31 (total of 31 days) ---------------------------------------------------------------- Grand Total of 76 days for 5 people NOTE: The "*" signifies travel that actually ends after 31-MAR-97 Respectfully submitted, James R. Lemen Frank M. Friedlaender Page 8 ------------------------------------------------------------------------------- NASA REPORT DOCUMENTATION PAGE (IN LIEU OF NASA FORM 1626) --------------------|--------------------------|------------------------------- 1. REPORT NO. | 2. GOVERNMENT | 3. RECIPIENT'S DR-01 | ACCESSION NO. | CATALOG NO. --------------------|--------------------------|------------------------------- 4. TITLE AND SUBTITLE | 5. REPORT DATE Monthly progress report - for the month of | 10 March 1997 February 1997 |------------------------------- | 6. PERFORMING ORG | CODE: O/H1-12 -----------------------------------------------|------------------------------- 7. AUTHOR(S) | 8. PERFORMING ORGANIZA- J. R. Lemen | TION REPORT NO: F. M. Friedlaender | |------------------------------- -----------------------------------------------|10. WORK UNIT NO. 9. PERFORMING ORGANIZATION NAME AND ADDRESS | Lockheed Palo Alto Research Labs B/252 |------------------------------- Solar & Astrophysics Laboratory O/H1-12 |11. CONTRACT OR GRANT NO. 3251 Hanover Street, Palo Alto Ca. 94304 | NAS8 - 40801 -----------------------------------------------|------------------------------- 12. SPONSORING AGENCY NAME AND ADDRESS |13. TYPE OF REPORT AND Marshall Space Flight Center (Explorer Program)| PERIOD COVERED Huntsville Alabama 35812 | Progress report for the month | of February 1997 |------------------------------- |14. SPONSORING AGENCY | CODE MSFC / AP32 -----------------------------------------------|------------------------------- 15. SUPPLEMENTARY NOTES ------------------------------------------------------------------------------- 16. ABSTRACT The SOLAR-A Mission is a program of the Institute of Space and Astronautical Science (ISAS), the Japanese agency for scientific space activity. The SOLAR-A satellite was launched on August 30, 1991, to study high energy phenomena in solar flares. As an international cooperative agreement, Lockheed, under NASA contract, is providing a scientific investigation and has prepared the Soft X-ray Telescope (SXT), one of the two primary experiments of the mission. --------------------------------------|---------------------------------------- 17. KEY WORDS (SUGGESTED BY | 18. DISTRIBUTION STATEMENT AUTHOR(S)) Solar-A, X-ray, CCD, | Space Science, Solar Physics ------------------------|-------------|----------|-----------------|----------- 19. SECURITY CLASSIF. | 20. SECURITY CLASSIF. | 21. NO OF PAGES |22. PRICE (OF THIS REPORT) | (OF THIS PAGE) | | None | None | 8 | ------------------------|------------------------|-----------------|----------- For sale by: Superintendent of Documents, U.S. Government Printing Office