DATA_SET_DESCRIPTION |
Data Set Overview
=================
Instrument P.I. : John D. Richardson
Data Supplier : John D. Richardson
Data sampling rate : 96 seconds
Data Set Start Time : 1979-06-25T00:03:19.072Z
Data Set Stop Time : 1979-07-05T09:53:42.070Z
This data set contains solar wind plasma data upstream of
Jupiter before the Voyager 2 encounter. Fit and moment
parameters are given; the fit parameters assume a convected
isotropic proton Maxwellian distribution. Use of fit
parameters is recommended as these are normally more accurate.
Since only the first 72 or last 72 energy/charge channels are
telemetered to Earth from each M-mode spectra, derived
parameters change significantly only every other set of
spectra so the effective time resolution is 196 s.
Parameters
==========
Data Set Parameter 'ION DENSITY'
--------------------------------
Data Set Parameter Name : ION DENSITY
Data Set Parameter Unit : CM**-3
Sampling Parameter Name : TIME
Sampling Parameter Unit : SECOND
Minimum Sampling Parameter : UNK
Maximum Sampling Parameter : UNK
Sampling Parameter Interval : UNK
Minimum Available Sampling Int : UNK
Noise Level : UNK
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 data set. 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.
Data Set Parameter 'ION TEMPERATURE'
------------------------------------
Data Set Parameter Name : ION TEMPERATURE
Data Set Parameter Unit : EV
Sampling Parameter Name : TIME
Sampling Parameter Unit : SECOND
Minimum Sampling Parameter : UNK
Maximum Sampling Parameter : UNK
Sampling Parameter Interval : UNK
Minimum Available Sampling Int : UNK
Noise Level : UNK
A derived parameter giving an indication of the mean
energy/ion, assuming the shape of the ion energy spectrum to
be Maxwellian. Given that the ion energy spectrum is not
exactly Maxwellian, the ion temperature can be defined
integrally (whereby the mean energy obtained by integrating
under the actual ion energy spectrum is set equal to the
integral under a Maxwellian, where the temperature is a free
parameter for which to solve), or differentially (whereby the
slopes of the actually ion energy spectrum at various energies
are matched to the slopes of a corresponding Maxwellian). The
temperature parameter is often qualified with a range of
applicable energies. Temperatures can be angularly
anisotropic. If the ions do not have a Maxwellian distribution
the actual distribution can be represented as the sum of
several Maxwellians, each with a separate temperature.
Data Set Parameter 'ION THERMAL SPEED'
--------------------------------------
Data Set Parameter Name : ION THERMAL SPEED
Data Set Parameter Unit : KM/S
Sampling Parameter Name : TIME
Sampling Parameter Unit : SECOND
Minimum Sampling Parameter : UNK
Maximum Sampling Parameter : UNK
Sampling Parameter Interval : UNK
Minimum Available Sampling Int : UNK
Noise Level : UNK
A measure of the velocity associated with the temperature of
the ions. It is formally defined as the Ion Thermal Speed
squared equals two times K (Boltzmann's constant) times T
(temperature of ion) divided by M (ion mass). Each component
of a plasma has a thermal speed associated with it.
Data Set Parameter 'ION VELOCITY'
---------------------------------
Data Set Parameter Name : ION VELOCITY
Data Set Parameter Unit : KM/S
Sampling Parameter Name : TIME
Sampling Parameter Unit : SECOND
Minimum Sampling Parameter : UNK
Maximum Sampling Parameter : UNK
Sampling Parameter Interval : UNK
Minimum Available Sampling Int : UNK
Noise Level : UNK
A derived parameter giving the average speed and direction of
motion of a plasma or plasma component. The velocity can be
obtained by taking the first moment of the distribution
function or by simulating the observations with some known
distribution function, usually a Maxwellian, to the
distribution. Velocities are given in Heliographic (RTN)
coordinates:
R is radially away from sun,
T is in plane of sun's equator and positive in the direction
of solar rotation
N completes right-handed system
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 VELOCITY
Instrument Parameter Name : ION CURRENT
Important Instrument Parameters : 1
Instrument Host ID : VG2
Data Set Parameter Name : ION TEMPERATURE
Instrument Parameter Name : ION RATE
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 TEMPERATURE
Instrument Parameter Name : ION CURRENT
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
Instrument Host ID : VG2
Data Set Parameter Name : ION TEMPERATURE
Instrument Parameter Name : PARTICLE MULTIPLE PARAMETERS
Important Instrument Parameters : 1
Data Coverage
=============
Filename Records Start Stop
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SWIND.TAB 7547 1979-06-25T00:03:19.072Z 1979-07-05T09:53:42.070Z
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