VEGA 1/2 MISCHA CD Version 1.1 Date 12. Aug. 1997 IWF Graz Magda Delva ============================================================================== DESCRIPTION OF THE CONTENTS OF THE FBT2SE FILE FOR VEGA MAGNETIC FIELD FLYBY PHASE DATA IWF, GRAZ, June 1996 Magda Delva ***************************************************************** 1. ABSTRACT ----------- The S*FBT2SE file of the magnetic field data, measured by the MISCHA - experiment on board of the Vega spacecraft, contains the following types of data: the position of the spacecraft in heliocentric (solar) ecliptic coordinates (H.SE), magnetic field data in a coordinate system centered at the spacecraft with x - axis to the sun and (x,y) - plane in its orbital plane (i.e. almost equal to the ecliptic). In addition, quality flags give information about missing or bad data. The magn. field data in these files are collected from THREE different modes: - for some time intervals (around closest approach), data are available with high time resolution (DT or 1 vector/(0.1 sec)); - for other intervals, data are available in HS mode = 1 vector/(6 sec); - for other intervals, data are available in T2 mode = 1 vector/(60 sec). Data have been AVERAGED down to a common resolution of 60 sec. So the whole file has an EQUAL time resolution of 1 vector/(60 sec). The times were have been averaged are in the header, in the list of intervals marked with DT, HS. H.SE - coordinate system: Heliocentric ecliptic coord. system: positions of the SC are given in this co. system: x-axis to equinox 1950., z-axis to ecliptic northpole, (x,y)-plane is the ecliptic plane. SE - coordinate system: Solar Ecliptic system: spacecraft-centered, x-axis to sun, (xy)-plane is orbital plane of spacecraft, i.e. nearly equal to the ecliptic plane, z-axis nearly to ecliptic pole. 2. DESCRIPTION OF THE HEADER - FILE ----------------------------------- name of header and data files: S1FBT1SE date files created: 6-FEB-96 record length of data file, in bytes: 56 number of columns: 13 number of rows: 5200 flag for missing data: 0.10E+33 # name units source type loc ---------------------------------------------------------------------------- 001 UT s VEGA-1 MISCHA T 0 =Time variable in seconds after 1 Jan. 1965 002 X H.SE 1950 km VEGA-1 MISCHA R 8 003 Y H.SE 1950 km VEGA-1 MISCHA R 12 004 Z H.SE 1950 km VEGA-1 MISCHA R 16 005 R H.SE 1950 km VEGA-1 MISCHA R 20 =Heliocentric rectangular ecliptic coord. of spacecraft, x-axis to vernal equinox, equinox 1950.0. 006 BX SE nT VEGA-1 MISCHA R 24 007 BY SE nT VEGA-1 MISCHA R 28 008 BZ SE nT VEGA-1 MISCHA R 32 009 BT SE nT VEGA-1 MISCHA R 36 =Magn. field comp. in spacecraft centered Solar Ecliptic system (x-axis to sun, y-axis opposite to SC-velocity, z approx. to ecliptic northpole) 010 Q.OFFSET VEGA-1 MISCHA R 40 =Quality flag for offset: 0 : offset o.k., no problems -1 : no offset available, calculation impossible 1 : offset available, but value can have an error. 011 Q.POS VEGA-1 MISCHA R 44 =Quality flag for position: 0 : position is o.k. -1 : no position available. 012 Q.ATT VEGA-1 MISCHA R 48 =Quality flag for attitude of spacecraft, i.e. orientation of original raw data (PSSO) coordinate system is available or not: 0 : three-axis-stabilisation and a full matrix A to transform from PSSO to SE is known -1 : no information about spacecraft orientation, no matrix A 1 : one-axis-orientation, only angle A0 between x-axis and direction to the sun is known, the SC can rotate freely around the x-axis. 013 Q.FLAG VEGA-1 MISCHA R 52 =Quality flag for glitches: 0 : data are o.k. 1 : here is a glitche. NOTES: Start time = 04-MAR-86 04:40:30.000 End time = 08-MAR-86 08:33:18.000 ABSTRACT ORBIT= OWNER= M.DELVA MODE = CAL + ROT RESOL= 60. SEC =type of data: calibrated and rotated data, resolution 60 seconds. COORDINATE SYSTEM= PSSO OFFSET= V1:-10.,-5.,40., V2:-11.,-10.,41. BPSSO = BORIGINAL - OFFSET SOURCE FILES: PSSO-file: B01FBT2 OFFSET-file: [VEGA.PROG]B01FBT1OFF POS-file: [VEGA.POSITION]VEG1POS Part 1: HS 04.03 04:40 / 04.03 04:59 Part 2: DT 04.03 06:00 / 04.03 08:00 Part 3: HS 04.03 08:51 / 04.03 08:53 Part 4: T2 04.03 08:54 / 05.03 03:35 Part 5: HS 05.03 03:35 / 05.03 03:43 Part 6: DT 05.03 06:00 / 05.03 08:00 Part 7: T2 05.03 09:54 / 06.03 02:53 Part 8: HS 06.03 03:11 / 06.03 03:13 Part 9: T2 06.03 03:14 / 06.03 03:53 Part 10: DT 06.03 04:17 / 06.03 08:25 Part 11: HS 06.03 08:51 / 06.03 08:53 Part 12: T2 06.03 08:54 / 07.03 06:33 Part 13: DT 07.03 08:14 / 07.03 10:11 Part 14: T2 07.03 10:53 / 08.03 08:33 Edited from the file: b01fbt2se =Internal information about origin of additional data for generation of masterfile. END