Data Set Information
DATA_SET_NAME VEGA1 DUST PARTICLE COUNTER MASS ANALYSER DATA V1.0
DATA_SET_ID VEGA1-C-DUCMA-3-RDR-HALLEY-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : Encounter Data for Vega-1 included two files: DSFAST17 and Dvega101. These files were submitted by the Univ of Chicago group with hard copy versions of the operating manual and a preprint of results. The following explanation of the contents of the two files is below. The DSFAST17 file includes all the fast telemetry data (data obtained every two seconds). The fast telemetry data covers the entire Halley's comet encounter, lasting approximately four hours. The telemetry noise events have not been removed from the data. Each readout includes; 1)the time at which data was obtained in seconds (given in time since the Vega launch date),and the Blissi clock described in the technical manual, 2) Two eight integer status commands also described in the Ducma Technical Manual, 3) two temperatures,the detector temperature and the electronic temperature explained in the technical manual, 4) the dust events given as ten integers which represent counts in each of four different thresholds,M4-M1,as well as the anticoincident counts,M4NV-M1NV, and the two V detector counts, VL and VH, which register noise events. More detailed explanations may be found in the Ducma technical manual which is available through PDS-SBN. The masses corresponding to thresholds M1 through M4 are given below: M1: 1.5x10**-13 g M2: 5.6x10**-11 g M3: 1.6x10**-9 g M4: 4.0x10 A sample data line appears as follows: Ducma Blissi Command Status Detector Elect.clock clock Temp. Temp.38252812 1 10100100 11011001 -18.01 30.86 M4 M3 M2 M1 M4NV M3NV M2NV M1NV VL VH0 0 1 2 0 0 0 0 0 0 Dvega101 file includes the encounter data without any information about status commands and temperature variations. The noise spikes have been removed. This file is designed for easy data analysis and lists simply the time of an event in seconds and the total counts in each threshold, M4-M1, the anticoincident events, M4NV-M1NV, and the noise events,VL and VH, all obtained during that time interval. Below are charts to help in the conversion of BLISSI clock times for Vega1 to DUCMA clock times and 'calendar time'. DUCMA times are given in seconds after launch BLISSI times are given in seconds Vega1DUCMA start time: Dec. 15 1984 10:33:37from file dsfast17.tab------------+-----------+--------------------------+--------------------+ DUCMA time |BLISSI time| DUCMA Time to CA | Real time | (seconds) | (seconds) | (seconds) |(DD hh:mm:ss) | (YY-MM-DDThh:mm:ss)|------------+-----------+-----------+--------------+--------------------+ 37910088 | 179 | 612424 | 07 02:07:04 | 86-02-27T05:13:02 | 37917104 | 7195 | 605408 | 07 00:10:08 | 86-02-27T07:09:58 | 38344948 | 8 | 177564 | 02 01:19:24 | 86-03-04T06:00:42 | 38352136 | 7196 | 170376 | 01 23:19:36 | 86-03-04T08:00:30 | 38431348 | 13 | 91164 | 01 01:19:24 | 86-03-05T06:00:42 | 38438524 | 7191 | 83988 | 00 23:19:48 | 86-03-05T08:00:18 | 38511536 | 2 | 10976 | 00 03:02:56 | 86-03-06T04:17:10 |* 38522512 | 10976 | 0 | 00 00:00:00 | 86-03-06T07:20:06 | 38526412 | 14878 | 3900 | 00 01:05:00 | 86-03-06T08:25:06 | 38612184 | 202 | 89672 | 01 00:54:32 | 86-03-07T08:14:38 | 38619168 | 7188 | 96656 | 01 02:50:56 | 86-03-07T10:11:02 |------------+-----------+-----------+--------------+--------------------+ *-times of Closest Approach (CA)
DATA_SET_RELEASE_DATE 3000-01-01T00:00:00.000Z
START_TIME 1986-02-27T05:13:02.000Z
STOP_TIME 1986-03-07T10:11:02.000Z
MISSION_NAME VEGA 1
MISSION_START_DATE 1984-12-15T12:00:00.000Z
MISSION_STOP_DATE 1986-04-01T12:00:00.000Z
TARGET_NAME HALLEY
TARGET_TYPE COMET
INSTRUMENT_HOST_ID VEGA1
INSTRUMENT_NAME DUST PARTICLE COUNTER AND MASS ANALYZER
INSTRUMENT_ID DUCMA
INSTRUMENT_TYPE PARTICLE COUNTER
NODE_NAME Small Bodies
ARCHIVE_STATUS ARCHIVED
CONFIDENCE_LEVEL_NOTE Confidence Level Overview : N/A
CITATION_DESCRIPTION Simpson, J.A., Rabinowitz, D., Tuzzolino, A. J., and A. V. Dyachkov, VEGA1 DUST PARTICLE COUNTER MASS ANALYSER DATA V1.0, VEGA1-C-DUCMA-3-RDR-HALLEY-V1.0, NASA Planetary Data System, 1989.
ABSTRACT_TEXT Encounter Data for Vega-1 included two files: DSFAST17 and Dvega101. These files were submitted by the Univ of Chicago group with hard copy versions of the operating manual and a preprint of results. The following explanation of the contents of the two files is below.
PRODUCER_FULL_NAME INTERNATIONAL HALLEY WATCH
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