PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 1998-05-01 NOTE = "DATASET.TXT contains the data set description." END_OBJECT = TEXT END Data Set Summary ================ Data Set ID: VG1-J-PLS-5-SUMM-ION-INBNDSWIND-96S-V1.0 Instrument: PLS Instrument P.I.: John D. Richardson Data Supplier: John D. Richardson Data sampling rate: 96 seconds Data Set Start time: 1979-02-15T00:03:10.173Z Data Set Stop time: 1979-03-02T13:05:31.348Z Record format ------------- These files can be read according to the FORTRAN format statement: '(a24,1x,f7.4,5(1x,f7.1),f7.4,5(1x,f7.1))' where 'a24' is the time stamp in PDS format: yyyy-mm-ddThh:mm:ss.sssZ. The individual elements of the time field can be read according to the statement: '(i4,4(1x,i2),1x,f6.3,1x)' year, month, day, hour, minute, seconds. Thus a record may alternatively be read according to the format: '(i4,4(1x,i2),1x,f6.3,2x,f7.4,5(1x,f7.1),f7.4,5(1x,f7.1))' Data column descriptions ------------------------ time a24 time in the format yyyy-mm-ddThh:mm:ss.sssZ mom_den f7.4 moment density mom_Vr f7.1 moment Vr mom_Vt f7.1 moment Vt mom_Vn f7.1 moment Vn mom_V f7.1 moment speed (magnitude of V) mom_wth f7.1 moment thermal speed fit_den f7.4 fit density fit_Vr f7.1 fit Vr fit_Vt f7.1 fit Vt fit_Vn f7.1 fit Vn fit_V f7.1 fit speed (magnitude of V) fit_wth f7.1 fit thermal speed Missing data flag value ----------------------- Any data column whose value is -9.9999 or -9999.9 (depending upon column format) is a missing data value. Data Description ================ Instrument P.I. : John D. Richardson Data Supplier : John D. Richardson Data sampling rate : 96 seconds Data Set Start Time : 1979-02-15T00:03:10.173Z Data Set Stop Time : 1979-03-02T13:05:31.348Z This data set contains solar wind plasma data upstream of Jupiter before the Voyager 1 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. 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 (i.e. highest entropy shape). 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 : 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 VELOCITY Instrument Parameter Name : ION CURRENT Important Instrument Parameters : 1 Instrument Host ID : VG1 Data Set Parameter Name : ION TEMPERATURE Instrument Parameter Name : ION RATE 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 : ION TEMPERATURE 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 Instrument Host ID : VG1 Data Set Parameter Name : ION TEMPERATURE Instrument Parameter Name : PARTICLE MULTIPLE PARAMETERS Important Instrument Parameters : 1 Data Coverage ------------- Filename Records Start Stop ------------------------------------------------------------------- T79046 11297 1979-02-15T00:03:10.173Z 1979-03-02T13:05:31.348Z Confidence Level Overview ------------------------- Inbound solar wind values should be accurate to within a few percent for all parameters.