Data Set Overview
    =================
      THIS DATA SET CONTAINS ESTIMATES OF THE ION MOMENT DENSITY IN
      THE PLS VOLTAGE RANGE (10-5950 EV/Q) AT SATURN DURING THE
      VOYAGER 1 ENCOUNTER.  RIGID COROTATION IS ASSUMED, WHICH LEADS
      TO AN UNDERESTIMATE OF THE DENSITY IN SOME REGIONS, AS DOES THE
      USE OF AN ACCEPTANCE AREA RELEVANT FOR A COLD BEAM FOR PLASMA
      WHICH IS TRANSONIC IS SOME REGIONS.  DENSITIES MAY BE
      UNDERESTIMATED BY A FACTOR OF 2-3 IN THE INNER MAGNETOSPHERE,
      SO THIS DATA SET SHOULD BE USED PRIMARILY FOR STUDIES USING
      VARIATIONS IN PLASMA DENSITY.  THE FIT DENSITIES GIVE A BETTER
      ESTIMATE OF THE ABSOLUTE DENSITY.  THIS IS THE DATA SHOWN AND
      DESCRIBED IN DETAIL IN LAZARUS AND MCNUTT (1983).  DATA FORMAT:
      COLUMNS 1-5 ARE TIME (YEAR, DAY, HOUR, MIN, SEC) AND COLUMN 6
      IS THE MOMENT DENSITY IN CM-3.  EACH ROW HAS FORMAT
      (I5,I4,2I3,I4,F8.3).  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 LAZARUS AND MCNUTT (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        : 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 number of ions per unit
        volume over a specified range of ion energy, energy/charge,
        or energy/nucleon.  Discrimination with regard to mass and or
        charge state is necessary to obtain this quantity, however,
        mass and charge state are often assumed due to instrument
        limitations.
 
        Many different forms of ion density are derived.  Some are
        distinguished by their composition (N+, proton, ion, etc.) or
        their method of derivation (Maxwellian fit, method of
        moments).  In some cases, more than one type of density will
        be provided in a single dataset.  In general, if more than
        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 DENSITY
      Instrument Parameter Name       : PARTICLE MULTIPLE PARAMETERS
      Important Instrument Parameters : 1
 
 
    Processing
    ==========
 
      Processing History
      ------------------
        Source Data Set ID          : VG1-PLS
        Software                    : MOMANAL
        Product Data Set ID         : VG1-S-PLS-5-ION-MOM-96.0SEC
 
 
      Software 'MOMANAL'
      ------------------
        Software Name               : MOMANAL
        Software Type               : PIN
        Software Release Date       : N/A
        Node ID                     : N/A
        Cognizant Engineer          : N/A
        Software Access Description : N/A

Overview
    ========
      THIS DATA SET PROVIDES AN ESTIMATE OF THE POSITIVE ION CHARGE
      DENSITY.  SEVERAL ASSUMPTION/SIMPLIFICATIONS ARE MADE TO
      SIMPLIFY THE ANALYSIS WHICH MAY AFFECT THE ACCURACY OF THE
      RESULTS.  HIGH MACH NUMBER FLOW IS ASSUMED; MACH NUMBERS OF 1,
      WHICH ARE OBSERVED IN THE INNER MAGNETOSPHERE, CAN RESULT IN
      50% UNDERESTIMATES OF THE CHARGE DENSITY.  THE ANALYSIS ASSUMES
      A UNIT RESPONSE (IE., ALL PARTICLES IN A COLD BEAM INCIDENT ON
      THE APERTURE OF THE EXPERIMENT WOULD BE MEASURED AT THE
      COLLECTOR).  THE ACTUAL RESPONSE IS AS LOW AS 70%.  A VELOCITY
      INTO THE DETECTOR MUST ALSO BE ASSUMED; THE VELOCITY USED IS
      THE COROTATION VELOCITY.  OBSERVATIONS INDICATE THAT IN SOME
      REGIONS THE ACTUAL VELOCITY IS AS LITTLE AS HALF OF THE
      COROTATION VELOCITY, GIVING FACTOR OF 2 ERRORS IN THE DENSITY.
      FINALLY, ONLY IONS IN THE PLS ENERGY RANGE (10-5950 EV/Q) ARE
      COUNTED.  THE CUMULATIVE ERROR FROM ALL THESE EFFECTS IS LESS
      THAN 10% IN THE SOLAR WIND, LESS THAN A FACTOR OF 2 IN THE
      OUTER MAGNETOSPHERE (R>10 RS), AND UP TO A FACTOR OF 3 INSIDE
      THIS.  SINCE THE AMPLITUDE OF EACH OF THESE EFFECTS VARIES
      SLOWLY IN TIME (DISTANCE), THE RELATIVE CHANGES IN DENSITY ARE
      GOOD TO 10 PERCENT IN MOST CASES.  THIS DATA SET IS MOST USEFUL
      FOR LOOKING AT DENSITY VARIATIONS; ION FIT DENSITIES ARE MUCH
      BETTER INDICATORS OF THE ABSOLUTE PLASMA DENSITY