VEGA 1/2 MISCHA CD Version 1.1 Date 12. Aug. 1997 IWF Graz Magda Delva ============================================================================== DESCRIPTION OF THE CONTENTS OF THE FBT1SE FILE FOR VEGA MAGNETIC FIELD FLYBY PHASE DATA IWF, GRAZ, June 1996 Magda Delva ***************************************************************** 1. ABSTRACT ----------- The S*FBT1SE 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 plane), z approx. to ecliptic northpole. In addition, quality flags give information about missing or bad data. The magn. field data in these filse are collected from FOUR 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); - for other intervals, data are available in T1 mode = 1 vector/(150 sec). Data have been AVERAGED down to a common resolution of 150 sec. So the whole file has an EQUAL time resolution of 1 vector/(150 sec). The times were have been averaged are in the header, in the list of intervals marked with DT, HS, T2. 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: 13-SEP-95 record length of data file, in bytes: 56 number of columns: 13 number of rows: 5262 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 = 28-FEB-86 10:16:08.000 End time = 10-MAR-86 23:59:34.000 ABSTRACT ORBIT= OWNER= M.DELVA MODE = CAL + ROT RESOL= 150 SEC = Trassa1-mode, calibrated and rotated, resolution= 1 vector/(150 sec) COORDINATE SYSTEM= PSSO OFFSET= V1:-10.,-5.,40., V2:-11.,-10.,41. BPSSO = BORIGINAL - OFFSET SOURCE FILES: PSSO-file: [VEGA.FLYBY]B01FBT1 OFFSET-file: B01FBT1OFF POS-file: [vega.position]veg1pos Part 1: T1 28.02 10:16 / 03.03 17:13 Part 2: HS 04.03 04:41 / 04.03 04:58 Part 3: DT 04.03 06:01 / 04.03 08:01 Part 4: HS 04.03 08:51 / 04.03 08:53 Part 5: T2 04.03 08:53 / 05.03 03:33 Part 6: HS 05.03 03:36 / 05.03 03:43 Part 7: DT 05.03 06:01 / 05.03 08:01 Part 8: T2 05.03 09:53 / 06.03 02:51 Part 9: HS 06.03 03:11 / 06.03 03:13 Part 10: T2 06.03 03:13 / 06.03 03:51 Part 11: DT 06.03 04:16 / 06.03 08:26 Part 12: HS 06.03 08:51 / 06.03 08:53 Part 13: T2 06.03 08:53 / 07.03 06:31 Part 14: DT 07.03 08:13 / 07.03 10:11 Part 15: T2 07.03 10:53 / 08.03 08:31 Part 16: T1 08.03 11:14 / 10.03 23:59 Edited from the file: b01fbt1se Done by M. DELVA date: 95-09-13 =Internal information about origin of additional data for generation of masterfile. END