Data Set Information
DATA_SET_NAME VOYAGER 1 SATURN PLASMA DERIVED ION FITS BROWSE 96 SEC
DATA_SET_ID VG1-S-PLS-5-ION-FBR-96.0SEC
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : THIS DATA SET CONTAINS THE ION DENSITIES, TEMPERATURES, AND VELOCITIES OBTAINED FROM VOYAGER 1 PLS DATA (VOLTAGE RANGE 10-5950 EV/Q) AT SATURN BY FITTING THE MEASURED SPECTRA WITH ISOTROPIC MAXWELLIAN DISTRIBUTIONS. IT IS A SUBSET OF THE DATA SET VG1-S-PLS-5-ION-FIT-96.0SEC WHICH SHOULD BE OBTAINED BEFORE THIS DATA IS USED. ONLY SPECTRA WHICH HAD DISTINCT CURRENT PEAKS WERE FIT. SPECTRA WERE FIT USING ONE OR TWO ION SPECIES, PROTONS AND/OR A HEAVY ION WHICH WAS TAKEN TO BE OXYGEN. OUTSIDE L:10-12 ION SPECTRA CHANGE RAPIDLY, SO THE VALUES IN THIS DATA SET DO NOT REPRESENT AVERAGE PLASMA CONDITIONS IN THE OUTER MAGNETOSPHERE. A COMPLETE DESCRIPTION OF THIS DATA SET IS GIVEN IN RICHARDSON (1986). DATA FORMAT: FIRST 5 COLUMNS ARE TIME TAG (YEAR, DAY, HOUR, MIN SEC.MSEC), FOLLOWED BY PROTON DENSITY (CM-3), PROTON TEMPERATURE (EV), HEAVY ION DENSITY (CM-3), HEAVY ION TEMPERATURE (EV), AND THREE VELOCITY COMPONENTS, (RHO, PHI,Z) IN KM/S. A CYLINDRICAL COORDINATE SYSTEM CENTERED ON THE PLANET IS USED, WITH RHO OUTWARDS FROM THE SPIN AXIS, PHI IN THE DIRECTION OF ROTATION, AND Z THE DISTANCE ABOVE THE EQUATOR. EACH ROW HAS THE FORMAT (2I4,2I3,F7.3,7E11.3). 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 RICHARDSON (1986) 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 : ION 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 EQUALING THE VECTOR MOMENTUM FRAME OR VELOCITY FRAME TO WHICH ONE MUST TRANSFORM IN A derived parameter equaling the number of ions per unit ION THERMAL SPEED: A measure of the velocity associated with ORDER TO YIELD ION ANGULAR DISTRIBUTIONS AND-OR the temperature of the ions. It is formally defined as the volume over a specified range of ion energy, energy/charge, ELECTRON ANGULAR DISTRIBUTIONS THAT ARE ANGULARLY Ion Thermal Speed squared equals two times K (Boltzmann's or energy/nucleon. Discrimination with regard to mass and or ISOTROPIC AT ALL ENERGIES. SUCH A FRAME CAN BE constant) times T (temperature of ion) divided by M (ion charge state is necessary to obtain this quantity, however, FOUND ONLY IF OTHER EFFECTS THAT CAN YIELD ANGULAR mass). Each component of a plasma has a thermal speed mass and charge state are often assumed due to instrument limitations. associated with it. ANISOTROPIES (E.G. SPATIAL GRADIENTS) ARE FACTORED OUT. THE COMPONENT OF THE TRANSFORM VELOCITY VECTOR PERPENDICULAR TO THE LOCAL Many different forms of ion density are derived. Some are MAGNETIC FIELD VECTOR IS COUPLED TO THE distinguished by their composition (N+, proton, ion, etc.) APPROXIMATELY TIME STATIONARY ELECTRIC FIELD. or their method of derivation (Maxwellian fit, method of PARALLEL TO THE LOCAL MAGNETIC FIELD VECTOR A FLOW moments). In some cases, more than one type of density will VELOCITY FRAME MAY OR MAY NOT BE A WELL DEFINED be provided in a single dataset. In general, if more than QUANTITY. one ion species is analyzed, either by moment or fit, a total density will be provided which is the sum of the ion densities. If a plasma component does not have a Maxwellian distribution the actual distribution can be represented as the sum of several Maxwellians, in which case the density of each Maxwellian is given. Source Instrument Parameters : Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION THERMAL SPEED Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : PLASMA VELOCITY Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION THERMAL SPEED Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : PARTICLE MULTIPLE PARAMETERS Important Instrument Parameters : 1 Processing : Processing History ------------------ Source Data Set ID : VG1-PLS Software : MJSANL Product Data Set ID : VG1-S-PLS-5-ION-FBR-96.0SEC Software 'MJSANL' ----------------- Software Name : MJSANL Software Type : PIN Software Release Date : N/A Node ID : N/A Cognizant Engineer : N/A Software Access Description : N/A
DATA_SET_RELEASE_DATE 1988-08-01T00:00:00.000Z
START_TIME 1980-11-12T08:47:23.550Z
STOP_TIME 1980-11-13T05:46:35.556Z
MISSION_NAME VOYAGER
MISSION_START_DATE 1972-07-01T12:00:00.000Z
MISSION_STOP_DATE N/A (ongoing)
TARGET_NAME SATURN
TARGET_TYPE PLANET
INSTRUMENT_HOST_ID VG1
INSTRUMENT_NAME PLASMA SCIENCE EXPERIMENT
INSTRUMENT_ID PLS
INSTRUMENT_TYPE PLASMA ANALYZER
NODE_NAME Planetary Plasma Interactions
ARCHIVE_STATUS ARCHIVED
CONFIDENCE_LEVEL_NOTE Overview : THIS DATA SET PROVIDES AN ESTIMATE OF THE ION PARAMETERS IN THE PLS ENERGY RANGE (10-5950 EV). FORMAL 1 SIGMA UNCERTAINTIES FOR THE DERIVED VELOCITIES, DENSITIES, AND THERMAL SPEEDS ARE GIVEN IN THE COMPLETE DATA SET AND RANGE FROM A FEW TO 100%. SYSTEMATIC ERRORS MAY RESULT FROM THE USE OF ISOTROPIC MAXWELLIAN DISTRIBUTIONS TO MODEL THE IONS. THIS RESULTS IN AN UNDERESTIMATE OF THE TOTAL ION DENSITY AND ION THERMAL SPEED OF LESS THAN 20%, BUT HAS LITTLE EFFECT (FEW PERCENT) ON THE VELOCITY DETERMINATION. ONLY CURRENT SPECTRA WITH AT LEAST ONE DISTINCT PEAK WERE FIT; THIS GIVES A BIASED SELECTION OF THE DATA, PARTICULARLY OUTSIDE L:10 WHERE THE DATA GIVEN IS NOT REPRESENTATIVE OF 'AVERAGE' PLASMA CONDITIONS. SEE RICHARDSON (1986) FOR DETAILS.
CITATION_DESCRIPTION Citation TBD
ABSTRACT_TEXT THIS DATA SET CONTAINS THE ION DENSITIES, TEMPERATURES, AND VELOCITIES OBTAINED FROM VOYAGER 1 PLS DATA (VOLTAGE RANGE 10-5950 EV/Q) AT SATURN BY FITTING THE MEASURED SPECTRA WITH ISOTROPIC MAXWELLIAN DISTRIBUTIONS. IT IS A SUBSET OF THE DATA SET VG1-S-PLS-5-ION-FIT-96.0SEC WHICH SHOULD BE OBTAINED BEFORE THIS DATA IS USED. ONLY SPECTRA WHICH HAD DISTINCT CURRENT PEAKS WERE FIT. SPECTRA WERE FIT USING ONE OR TWO ION SPECIES, PROTONS AND/OR A HEAVY ION WHICH WAS TAKEN TO BE OXYGEN. OUTSIDE L:10-12 ION SPECTRA CHANGE RAPIDLY, SO THE VALUES IN THIS DATA SET DO NOT REPRESENT AVERAGE PLASMA CONDITIONS IN THE OUTER MAGNETOSPHERE. A COMPLETE DESCRIPTION OF THIS DATA SET IS GIVEN IN RICHARDSON (1986). DATA FORMAT: FIRST 5 COLUMNS ARE TIME TAG (YEAR, DAY, HOUR, MIN SEC.MSEC), FOLLOWED BY PROTON DENSITY (CM-3), PROTON TEMPERATURE (EV), HEAVY ION DENSITY (CM-3), HEAVY ION TEMPERATURE (EV), AND THREE VELOCITY COMPONENTS, (RHO, PHI,Z) IN KM/S. A CYLINDRICAL COORDINATE SYSTEM CENTERED ON THE PLANET IS USED, WITH RHO OUTWARDS FROM THE SPIN AXIS, PHI IN THE DIRECTION OF ROTATION, AND Z THE DISTANCE ABOVE THE EQUATOR. EACH ROW HAS THE FORMAT (2I4,2I3,F7.3,7E11.3). 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 RICHARDSON (1986) AND A COMPLETE INSTRUMENT DESCRIPTION CAN BE FOUND IN BRIDGE (1977).
PRODUCER_FULL_NAME JOHN D. RICHARDSON
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