Data Set Information
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| DATA_SET_NAME |
VOYAGER 1 SATURN PLASMA DERIVED ELECTRON PARAMETERS 96 SEC
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| DATA_SET_ID |
VG1-S-PLS-5-ELE-PAR-96.0SEC
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
Data Set Overview : THIS DATA SET CONTAINS ELECTRON PARAMETERS IN THE PLS ENERGY RANGE (10-5950 EV) AT SATURN DURING THE VOYAGER 1 ENCOUNTER. PARAMETERS ARE CALCULATED IN SEVERAL WAYS. TOTAL MOMENT DENSITY AND TEMPERATURE ARE GIVEN. EACH ELECTRON SPECTRUM IS ALSO FIT WITH A THERMAL COMPONENT AND 1-3 HOT COMPONENTS DEPENDING ON HOW MANY MAXWELLIANS ARE NEEDED TO FIT THE ENTIRE DISTRIBUTION. THE MOMENT DENSITY AND TEMPERATURE OF THE HOT COMPONENT IS CALCULATED AFTER THE THERMAL COMPONENT IS SUBTRACTED FROM THE SPECTRUM. THE CHI-SQUARE VALUE FOR EACH FIT IS GIVEN. THE SPACECRAFT CHARGE IS NOT TAKEN INTO ACCOUNT, AND MAY RESULT IN FACTOR OF 2-3 ERRORS IN THE THERMAL ELECTRON DENSITY. DATA IS UNRELIABLE INSIDE 6 RS AND IN THE OCCULTATION REGIONS. A COMPLETE DESCRIPTION OF THIS DATA SET IS IN SITTLER ET AL. (1983). DATA FORMAT: THE DATA SET IS IN ASC FORMAT AND CAN BE READ USING THE FOLLOWING FORTRAN STATEMENT:\n READ(22,999) JTIME,IMAX,IFLY,EDATA FORMAT(8I6,17G12.5,/,1X,10G12.5) THE PARAMETER DEFINITIONS ARE: NAME TYPE DEFINITION JTIME(1-6) I*4 YR,DAY,HR,MIN,SEC,MSEC IMAX ' # OF POINTS IN SPECTRUM (INCLUDES 11 PTS BELOW 10 EV FOR MOM INTEGRALS) IFLY ' FLAG : 0 FOR CRUISE AND :1 FOR ENCOUNTER EDATA(1) R*4 THBN(ANGLE BETWEEN DCUP NORMAL AND B VECTOR) 2 ' RNE MOMENT ELECTRON DENSITY (/CM**3) 3 ' RTE ' ' TEMPERATURE (EV) 4 ' PHISC SPACECRAFT POTENTIAL (VOLTS) 5 ' RNC COLD ELECTRON DENSITY (/CM**3) 6 ' SGNC STANDARD DEVIATION OF RNC (/CM**3) 7 ' RTC COLD ELECTRON TEMPERATURE (EV) 8 ' SGTC STANDARD DEVIATION OF RTC (EV) 9 ' CHIC CHI-SQUARE OF COLD FIT 10 ' RNH1 1ST HOT ELECTRON DENSITY (/CM**3) 11 ' SGNH1 STANDARD DEVIATION OF RNH1 (/CM**3) 12 ' TH1 1ST HOT ELECTRON TEMPERATURE (EV) 13 ' SGTH1 STANDARD DEVIATION OF TH1 (EV) 14 ' CHIH1 CHI-SQUARE OF 1ST HOT FIT 15 ' RNH2 2ND HOT ELECTRON DENSITY (/CM**3) 16 ' SGNH2 STANDARD DEVIATION OF RNH2 (/CM**3) 17 ' TH2 2ND HOT ELECTRON TEMPERATURE (EV) 18 ' SGTH2 STANDARD DEVIATION OF TH2 (EV) 19 ' CHIH2 CHI-SQUARE OF 2ND HOT FIT 20 ' RNH3 3RD HOT ELECTRON DENSITY (/CM**3) 21 ' SGNH3 STANDARD DEVIATION OF RNH3 (/CM**3) 22 ' TH3 3RD HOT ELECTRON TEMPERATURE (EV) 23 ' SGTH3 STANDARD DEVIATION OF TH3 (EV) 24 ' CHIH3 CHI-SQUARE OF 3RD HOT FIT 25 ' CHI CHI-SQUARE FOR TOTAL FIT 26 ' RNH MOMENT HOT ELECTRON DENSITY (/CM**3) 27 ' RTH MOMENT HOT ELECTRON TEMPERATURE (EV) IN COMPUTING RNH1,TH1 WE USED THE 3RD TO 7TH CHANNELS ABOVE THE BREAKPOINT ENERGY EB1 AND SUBTRACTED THE COLD COMPONENT FC FROM FE (OBSERVED) BEFORE DOING THE FIT. IN REALITY THIS FIT WAS DONE ITERATIVELY BETWEEN THE COLD AND HOT COMPONENT FITS (FC:FE-FH AND FH:FE-FC ETC.). A SIMILAR APPROACH WAS USED IN COMPUTING RNH3,TH3 FOR WHICH A MAXWELLIAN FIT WAS DONE TO THOSE CHANNELS ABOVE EB2. THE PARAMETERS RNH2,TH2 WERE FIT TO THE UPPER 5 (3 MIN) CHANNELS (GENERALLY ABOVE EB2). THIS FIT WAS PRIMARILY DONE TO ALLOW PROPER ESTIMATION OF FE TO THE HIGH ENERGY PORTION OF THE SPECTRUM. IN MANY CASES THERE ARE NOT SUFFICIENT POINTS TO COMPUTE RNH3,TH3 AND RNH2,TH2 DO PROVIDE A FAIR REPRESENTATION OF THE SPECTRUM. IF RNH1:RNH2:RNH3 THEN YOU SHOULD NOT USE THE 2ND AND 3RD FIT PARAMETERS. VALUES OF 1.E32 INDICATE THAT THE PARAMETER COULD NOT BE OBTAINED FROM THE DATA USING THE STANDARD ANALYSIS TECHNIQUE. ADDITIONAL INFORMATION ABOUT THIS DATASET AND THE INSTRUMENT WHICH PRODUCED IT CAN BE FOUND ELSEWHERE IN THIS CATALOG. AN OVERVIEW OF THE DATA IN THIS DATA SET CAN BE FOUND IN SITTLER ET AL. (1983) AND A COMPLETE INSTRUMENT DESCRIPTION CAN BE FOUND IN BRIDGE (1977). Processing Level Id : 5 Software Flag : Y Parameters : Sampling Parameter Name : TIME Data Set Parameter Name : ELECTRON DENSITY Sampling Parameter Resolution : 96.000000 Sampling Parameter Interval : 96.000000 Minimum Available Sampling Int : 96.000000 Data Set Parameter Unit : CM-3 Sampling Parameter Unit : SECOND Description ----------- A derived parameter giving an indication of the mean A derived parameter equaling the number of electrons per unit volume over a specified range of electron energy. energy/electron, assuming the shape of the electron energy Different forms of electron density are derived spectrum to be Maxwellian (i.e.highest entropy shape). Given distinguished by method of derivation (Maxwellian fit, that the electron energy spectrum is not exactly Maxwellian, method of moments) or by the some selection criteria (ie., the electron temperature can be defined integrally (whereby the mean energy obtained by integrating under the actual hot electron and cold electron density). In general, if more electron energy spectrum is set equal to the integral under than one electron component is analyzed, either by moment or fit, a total density will be provided which is the sum of a Maxwellian, where the temperature is a free parameter for the electron densities. If the electron do not have a which to solve), or differentially (whereby the slopes of Maxwellian distribution the actual distribution can be the actually electron energy spectrum at various energies are matched to the slopes of a corresponding Maxwellian). represented as the sum of several Maxwellians, in which case the density of each Maxwellian is given. The temperature parameter is often qualified with a range of applicable energies. temperatures can be angularly anisotropic. If the electrons do not have a Maxwellian distribution the actual distribution can be represented as the sum of several Maxwellians, each with a separate temperature. Source Instrument Parameters : Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON DENSITY Instrument Parameter Name : ELECTRON RATE Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON DENSITY Instrument Parameter Name : ELECTRON CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON TEMPERATURE Instrument Parameter Name : ELECTRON RATE Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON TEMPERATURE Instrument Parameter Name : ELECTRON CURRENT Important Instrument Parameters : 1 Processing : N/A
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| DATA_SET_RELEASE_DATE |
1988-08-01T00:00:00.000Z
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| START_TIME |
1980-11-12T12:00:30.505Z
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| STOP_TIME |
1980-11-13T06:30:54.537Z
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| MISSION_NAME |
VOYAGER
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| MISSION_START_DATE |
1972-07-01T12:00:00.000Z
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| MISSION_STOP_DATE |
N/A (ongoing)
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| TARGET_NAME |
SATURN
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| TARGET_TYPE |
PLANET
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| INSTRUMENT_HOST_ID |
VG1
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| INSTRUMENT_NAME |
PLASMA SCIENCE EXPERIMENT
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| INSTRUMENT_ID |
PLS
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| INSTRUMENT_TYPE |
PLASMA ANALYZER
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| NODE_NAME |
Planetary Plasma Interactions
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| ARCHIVE_STATUS |
ARCHIVED
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| CONFIDENCE_LEVEL_NOTE |
Overview : THIS DATA SET PROVIDES AN ESTIMATE OF THE ELECTRON PARAMETERS IN THE PLS ENERGY RANGE (10-5950 EV). THE THERMAL ELECTRON DENSITY MAY BE UNDERESTIMATED BY FACTORS OF 2-3 IN SOME REGIONS DUE TO NEGATIVE SPACECRAFT CHARGING. THERMAL ELECTRON PARAMETERS ARE ALSO UNRELIABLE INSIDE SIX KRONIAN RADII WHERE ELECTRON TEMPERATURES ARE COLD AND IN THE OCCULTATION REGIONS. HOT ELECTRONS ARE RELATIVELY UNDISTURBED BY CHARGING AND THESE PARAMETERS HAVE UNCERTAINTIES OF LESS THAN 20%.
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| CITATION_DESCRIPTION |
Citation TBD
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| ABSTRACT_TEXT |
THIS DATA SET CONTAINS ELECTRON PARAMETERS IN THE PLS ENERGY RANGE (10-5950 EV) AT SATURN DURING THE VOYAGER 1 ENCOUNTER. PARAMETERS ARE CALCULATED IN SEVERAL WAYS. TOTAL MOMENT DENSITY AND TEMPERATURE ARE GIVEN. EACH ELECTRON SPECTRUM IS ALSO FIT WITH A THERMAL COMPONENT AND 1-3 HOT COMPONENTS DEPENDING ON HOW MANY MAXWELLIANS ARE NEEDED TO FIT THE ENTIRE DISTRIBUTION. THE MOMENT DENSITY AND TEMPERATURE OF THE HOT COMPONENT IS CALCULATED AFTER THE THERMAL COMPONENT IS SUBTRACTED FROM THE SPECTRUM. THE CHI-SQUARE VALUE FOR EACH FIT IS GIVEN. THE SPACECRAFT CHARGE IS NOT TAKEN INTO ACCOUNT, AND MAY RESULT IN FACTOR OF 2-3 ERRORS IN THE THERMAL ELECTRON DENSITY. DATA IS UNRELIABLE INSIDE 6 RS AND IN THE OCCULTATION REGIONS. A COMPLETE DESCRIPTION OF THIS DATA SET IS IN SITTLER ET AL. (1983). DATA FORMAT: THE DATA SET IS IN ASC FORMAT AND CAN BE READ USING THE FOLLOWING FORTRAN STATEMENT:\n
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| PRODUCER_FULL_NAME |
JOHN D. RICHARDSON
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| SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
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