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VOYAGER 2 SATURN PLASMA DERIVED ION FITS 96 SEC (PDS)

NSSDCA ID: PSFP-00573

Availability: Archived at NSSDC, accessible from elsewhere

Time span: 1981-08-25 to 1981-08-26

Description

This description was generated automatically using input from the Planetary Data System.

Data Set Overview ================= THIS DATA SET CONTAINS THE ION PARAMETERS IN THE PLS VOLTAGE RANGE (10-5950 EV/Q) WITH FORMAL 1 SIGMA ERRORS OBTAINED FROM VOYAGER 2 DATA AT SATURN BY FITTING THE MEASURED SPECTRA WITH ISOTROPIC MAXWELLIAN DISTRIBUTIONS TO OBTAIN PLASMA DENSITIES, TEMPERATURES, AND VELOCITY. 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 NITROGEN OUTSIDE OF 14 RS AND OXYGEN ELSEWHERE. 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. THE VALUES FOR POSITION AND MAGNETIC FIELD GIVEN IN THE DATA SET ARE ONLY APPROXIMATE AND SHOULD NOT BE USED FOR PUBLICATION. PARAMETERS WHICH ARE IDENTICALLY 0 AND HAVE UNCERTAINTIES OF 0 WERE NOT FIT DUE TO INSUFFICIENT DATA; THESE NUMBERS ARE THUS NOT REAL VALUES. A COMPLETE DESCRIPTION OF THIS DATA SET IS GIVEN IN RICHARDSON (1986). DATA FORMATS ARE GIVEN AS BELOW: ================================================================ name type description ---------------------------------------------------------------time A24 time in the format yyyy-mm-ddThh:mm:ss.sssZ r 1PE11.4 spacecraft radial distance from planet (planetary radii) rho 1PE11.4 spacecraft position angle rho (radians) brho 1PE10.3 rho component of magnetic field (nT) bphi 1PE10.3 phi component of magnetic field (nT) bz 1PE10.3 z component of magnetic field (nT) mode A2 intrument mode (L or M) fdate A10 date the fit was performed (MMDDYY) who A6 intitials of person performing fit (JDR = Dr. John Richardson, MIT) chi2 1PE10.3 chi squared for the fit num_fit I3 number of ion species fit ionspec1 I3 atomic number of first ion species for the fit ionmass1 I3 mass of the first ion species for the fit (amu) ionchrg1 I3 char of the first ion species for the fit den1 1PE10.3 denisty of the first ion species for the fit (cnts/cm**3) xden1 1PE10.3 1 sigma uncertainty for den1 (cnts/cm**3) vrho1 1PE10.3 velocity vector rho component of 1st ion species (cm/sec) xvrho1 1PE10.3 1 sigma uncertainty for vrho1 (cm/sec) vphi1 1PE10.3 velocity vector phi component of 1st ion species (cm/sec) xvphi1 1PE10.3 1 sigma uncertainty for vphi1 (cm/sec) vz1 1PE10.3 velocity vector z component of 1st ion species (cm/sec) xvz1 1PE10.3 1 sigma uncertainty for vz1 (cm/sec) wpar1 1PE10.3 thermal speed in parallel direction (cm/sec) xwpar1 1PE10.3 1 sigma uncertainty for wpar1 (cm/sec) wper1 1PE10.3 thermal speed in perpendicular direction (cm/sec) xwper1 1PE10.3 1 sigma uncertainty for wper1 (cm/sec) ionspec2 I3 atomic number of second ion species for the fit ionmass2 I3 mass of the second ion species for the fit (amu) ionchrg2 I3 char of the second ion species for the fit den2 1PE10.3 denisty of the second ion species for the fit (cnt/cm**3) xden2 1PE10.3 1 sigma uncertainty for den2 (cnts/cm**3) vrho2 1PE10.3 velocity vector rho component of 2nd ion species (cm/sec) xvrho2 1PE10.3 1 sigma uncertainty for vrho2 (cm/sec) vphi2 1PE10.3 velocity vector phi component of 2nd ion species (cm/sec) xvphi2 1PE10.3 1 sigma uncertainty for vphi2 (cm/sec) vz2 1PE10.3 velocity vector z component of 2nd ion species (cm/sec) xvz2 1PE10.3 1 sigma uncertainty for vz2 (cm/sec) wpar2 1PE10.3 thermal speed in parallel direction (cm/sec) xwpar2 1PE10.3 1 sigma uncertainty for wpar2 (cm/sec) wper2 1PE10.3 thermal speed in perpendicular direction (cm/sec) xwper2 1PE10.3 1 sigma uncertainty for wper2 (cm/sec) 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 data set. 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 : VG2 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : ION THERMAL SPEED Instrument Parameter Name : ION RATE Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : ION THERMAL SPEED Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG2 Data Set Parameter Name : ION DENSITY Instrument Parameter Name : PARTICLE MULTIPLE PARAMETERS Important Instrument Parameters : 1 Processing ========== Processing History -----------------Source Data Set ID : VG2-PLS Software : MJSANL Product Data Set ID : VG2-S-PLS-5-ION-FIT-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

These data are available on-line from the Planetary Data System (PDS) at:

https://pds-ppi.igpp.ucla.edu/data/VG2-S-PLS-5-SUMM-ION-FIT-96SEC-V1.0/

Alternate Names

  • VG2-S-PLS-5-SUMM-ION-FIT-96SEC-V1.0

Discipline

  • Planetary Science: Fields and Particles

Additional Information

Spacecraft

Questions and comments about this data collection can be directed to: Dr. Edwin V. Bell, II

 

Personnel

NameRoleOriginal AffiliationE-mail
Dr. John D. RichardsonGeneral ContactMassachusetts Institute of Technologyjdr@space.mit.edu
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