**NSSDCA ID:** PSFP-00499

**Availability:** Archived at NSSDC, accessible from elsewhere

**Time span:** 1979-03-01 to 1979-03-07

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

Data Set Overview ================= Version 1.1 ----------This version 1.1 data set replaces the version 1.0 data set (DATA_SET_ID = VG1-J-PLS/PRA-5-ELE-MOM-96.0SEC) previously archived with the PDS. Data Set Description -------------------This data set contains derived values of the electron density and moment temperature at Jupiter during the Voyager 1 encounter in the PLS voltage range (10-5950 eV/q). Adjacent low and high energy electron measurements are combined to form a composite spectra which is used for the moment calculation. The moment calculations are performed as described in [SCUDDERETAL1981]. These assume isotropic distributions and correct for positive spacecraft charge when applicable and interpolate electron spectra below the 10 eV instrument threshold before performing the integration over velocity. On day 64 from 415-1830 negative charging of the spacecraft renders electron moment densities unreliable. Therefore, the PLS ion densities were used to derive electron densities from 0415-1400 assuming charge neutrality and from 1830-1940 using a model based on inbound plasma parameters. PRA densities were used to derive electron densities from 1400 to 1830. Electron temperatures derived from PLS electron data are used except inside L=5.4, where T[E] was set equal to T[I] and should be considered an upper limit. The data used from 415-1830 on day 64 are described in [SITTLER&STROBEL1987]. Data format: column 1 is time (yyyy-mm-ddThh:mm:ss.sssZ), column 2 is the moment density in cm^-3, column 3 the temperature in eV. Each row has format (a24, 2(1x,1pe9.2)). Values of -9.99e+10 indicate that the parameter could not be obtained from the data using the standard analysis technique. Additional information about this data set 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 [SCUDDERETAL1981] and [SITTLER&STROBEL1987] and a complete instrument description can be found in [BRIDGEETAL1977]. Processing Level Id : 5 Software Flag : Y Processing Start Time : UNK Processing Stop Time : UNK Parameters ========== Sampling Parameter Name : TIME Data Set Parameter Name : ELECTRON 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 A derived parameter equaling the number of electrons per unit volume over a specified range of electron energy. Different forms of electron density are distinguished by method of derivation (Maxwellian fit, method of moments) or by some selection criteria (ie., hot electron and cold electron density). In general, if more than one electron component is analyzed, either by moment or fit, a total density will be provided which is the sum of the electron densities. If the electrons do 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. Sampling Parameter Name : TIME Data Set Parameter Name : ELECTRON TEMPERATURE Sampling Parameter Resolution : 96.000000 Sampling Parameter Interval : 96.000000 Minimum Available Sampling Int : 96.000000 Data Set Parameter Unit : EV Sampling Parameter Unit : SECOND A derived parameter giving an indication of the mean energy/electron, assuming the shape of the electron energy derived spectrum to be Maxwellian. Given that the electron energy spectrum is not exactly Maxwellian, the electron temperature can be defined integrally (whereby the mean energy obtained by integrating under the actual electron 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 electron 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 electrons do not have a Maxwellian distribution the actual distribution can be represented as the sum of several Maxwellians, each with a separate temperature. Source Instrument Parameters ============================ Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON DENSITY Instrument Parameter Name : ELECTRON RATE ELECTRON CURRENT Important Instrument Parameters : 1 (for both inst. parameters) Instrument Host ID : VG1 Data Set Parameter Name : ELECTRON TEMPERATURE Instrument Parameter Name : ELECTRON RATE ELECTRON CURRENT Important Instrument Parameters : 1 (for both inst. parameters) Processing ========== Processing History -----------------Source Data Set ID : VG1-PLS Software : UNK Product Data Set ID : VG1-J-PLS/PRA-5-ELE-MOM-96.0SEC Data Coverage ============= Filename Records Start Stop ------------------------------------------------------------------T790301 5380 1979-03-01T12:27:43.435Z 1979-03-07T11:59:03.738Z

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

https://pds-ppi.igpp.ucla.edu/data/VG1-J-PLS-5-SUMM-ELE-MOM-96.0SEC-V1.1/

- VG1-J-PLS-5-SUMM-ELE-MOM-96.0SEC-V1.1

- Planetary Science: Fields and Particles

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

Name | Role | Original Affiliation | |
---|---|---|---|

Dr. John D. Richardson | General Contact | Massachusetts Institute of Technology | jdr@space.mit.edu |