File name: LYA_HISTORY.DOC Date: June 2, 1992 Created by: Jeff Culwell edited June 3,92 KES Purpose of this file: This file was created in order to keep track of information and data files used in analysis of EUV Lyman-alpha (Ly-a) MRO data by Pryor and Barth. On June 1, 1992, while preparing to analyze the 1990-1992 Ly-a data sets, we wanted to document what procedures and files had been used in the initial analysis. Also, new z-axis position and spin data were now available and how to include these changes needed to be documented as well. Therefore, this file was designed to document the changes and updates to procedures, programs, and data files. =============================================================================== Part One: Original Processing of Launch to May 1991 data ============================================================================== A. Locations and Contents of Data files.... Location (see#) Filename Contains... ------------------------------------------------------------------------------ [GLLSEQ.HISTORY] ALLSPIN_DUALSPIN.LIS Spin Rate changes based on ORPRO sequencing products. Calls to PCINIT and PCREST imply spin rate. [GLLSEQ.HISTORY] SITURN.LIS -Z axis pointing based on ORPRO sequencing products. Calls to SITURN include Ra/Dec. [GLLSEQ.HISTORY] EUV_START.DAT EUV microprocessor start cmds or FPNT changes from sequence or Real Time Command sources. [GLLSEQ.HISTORY] EUV_STOP.DAT EUV microprocessor stop cmds, as above. [GLL_RAW.MROH] MRO_INFO.DAT Time, z-axis, spin rate, EME50 x, y, z, and radial dist. from sun, and integration time for all MRO difference data sets. [GLL_RAW.MROH] MRO_HEADER.INFO Filename, time (SCE and SCLK) of all MRO data files. [GLL_RAW.MROH] FILELIST.LIS List of all MRO files and a flag indicating the status of the data. [GLL_RAW.MROH] MRO_FILELIST.LIS A list of all MRO data files with 2-3 days of integration time between them: for Ly-a analysis. [GLL_RAW.MROH] GLL_XYZ_EMO.DAT A listing of date, EME50 X, Y, Z and the radial dist. of GLL from the sun every day since launch. From SPK kernels. #(Note: The above files are all contained on DISKH) ------------------------------------------------------------------------------ B. Locations, files updated by, and files used by programs... Program Name Files used Files updated ------------------------------------------------------------------------------ In [GLLSEQ.SOFTWARE]: AACS.PRO ORPRO seq. products SITURN.LIS ALLSPIN_DUALSPIN.LIS In [GLL_RAW.SOFTWARE]: MRO_FILENAME.PRO DIR_EUV_MRO.LIS FILELIST.LIS (Temporary file) MRO_HEADER.PRO FILELIST.LIS MRO_HEADER.INFO MRO_INFO.PRO ALLSPIN_DUALSPIN.LIS MRO_INFO.DAT SITURN.LIS EUV_START.DAT EUV_STOP.DAT GLL_XYZ_EMO.DAT MRO_FILELIST.LIS individual .MRO files MRO_INFO.COM User inputs MRO_FILELIST.LIS (Note: MRO_INFO.COM runs MRO_FILENAME.PRO, MRO_HEADER.PRO, and MRO_INFO.PRO. Keith Naviaux wrote this .COM procedure to simplify the process of updating all of these data files.) =============================================================================== Part Two. First updates to the process =============================================================================== A. November 7, 1991 On September 10, 1991, LASP received the first MRO that had a RIM time greater than 999999:99:9:9. This left the old naming convention invalid. This convention was EUV_xxxxxx_xx.MRO. The change was made to EUVxxxxxxx_xx.MRO. Since one of the programs ran based on the old naming convention it was updated. The original program, [GLL_RAW.MROH]MRO_FILENAME.PRO, was changed to [GLL_RAW.MROH]MRO_FILENM.PRO. Also, in order to preserve the old data file we updated the file FILELIST.LIS to FILELIST2.LIS, the file updated by the new program. ------------------------------------------------------------------------------ B. April 17, 1992 This update was made in order to make the MRO_INFO.PRO program "smart" enough to translate Day Of Year (DOY) of a leap year into the proper month and day of that year. The only change was an internal one to the program MRO_INFO.PRO. No other changes occurred at this time. ============================================================================== Part Three. Updates in May and June of 1992 ============================================================================== A. Updates due to spacecraft operation by realtime (not sequenced) commands. Spacecraft "safing" due to Fault Protection and to the High Gain Antenna (HGA) deployment failure caused problems with the spacecraft attitude and spin knowledge normally obtained from pre-planned sequence periods. Also, improved knowledge of Z-axis position and spin rate obtained from "after-the-fact" navigation products are currently being verified for use instead of the commanded position and spin information. ____________________________________________________________________________ B. Updates due to improved knowledge During spacecraft safing, when the onboard computer controls the spacecraft attitude and spin (usually by keeping the -Z axis pointed at the sun), no planned sequences are available. Thus the information need to update the data files could no longer be extracted from the ORPROs. During these periods we update the SITURN.LIS and ALLSPIN_DUALSPIN.LIS files as information becomes available. This information can come from a "mini- sequence" constructed for realtime transmission; Keith usually gets a Sequence of Events (SEF) file from the Orbit Engineering Team (OET) shortly after it is sent to the spacecraft. Other realtime command information, Bill O'Neil's Weekly Mission Director's Report (MDR), the Space Flight Operations Schedule (SFOS) or simply by email request to the OET can also contain this information. Once these files have been hand updated, the other data files can be updated in the usual fashion. In updating the SITURN.LIS and ALLSPIN_DUALSPIN.LIS files for the long period of safing due to the HGA deployment failure we learned that the commands to change the spin rate (due to the spacecraft mode - allspin, dualspin, etc) and position were also in the SEF product. At this point we also learned that the time of the event given in the SEF is more accurate than the time of the PCINIT and PCREST commands of the ORPRO. In searching the SEF for Z-axis changes we discovered that two commands are able to update this position, 7SUN and 7TURN, and that more than one command can change the mode as well: 7MODE, 7SLEW, 7INIT, and 7SUN can all change the spacecraft mode. See the Command Dictionary (625-505) or the program header of SPIN_RATE.PRO found in [CULWELL.SOFTWARE]. The following data files have been affected by this improved knowledge: SITURN.LIS: ----------------------------- This file has been split into two files. The original file is the same. A new file has been created, SITURN_PLUS.LIS, which will reflect the Z-axis position and spin based on data from the following sources (in preference order): i) direct position and spin data from the Rotor C kernels, ii) commanded position and spin from the SEF iii) implied data based on the SFOS, Realtime Command forms, and/or the MDR in conjunction with the sun and spacecraft position from the SPK kernels ALLSPIN_DUALSPIN.LIS ----------------------------- This file remains unchanged, however, there is a new file called SPIN_RATE.LIS that contains all sequencing commands since launch that could have affected the spacecraft mode (7MODE, 7INIT, 7SLEW, 7SUN). For the two above files (SITURN.LIS and ALLSPIN_DUALSPIN.LIS) there is a file called SPIN_HISTORY.LIS that contains a low resolution listing of spin rate, RA and DEC of the spacecraft based on C kernel information. Since Rotor C kernels are not (currently) continuous from launch there are many large time gaps in these files. Yet, these are the most accurate source of information on spacecraft status. Please note (June 3, 1992) that the new files mentioned about the SITURN.LIS and ALLSPIN_DUALSPIN.LIS have yet to be verified. JSC. -- and should not be used. KES