- Data Set Overview
- =================
This Data Set consists of 4 s edited, Wave Electric Field Intensities from the Voyager 2 Plasma Wave Receiver Spectrum Analyzer obtained in the Vicinity of the Neptunian Magnetosphere. For each 4 s Interval, a Field Strength is determined for each of the sixteen Spectrum Analyzer Channels whose Center Frequencies range from 10 Hz to 56.2 kHz and which are logarithmically spaced in Frequency, four Channels per Decade. The Time associated with each Set of Intensities (sixteen Channels) is the Time of the Beginning of the Scan. During Data Gaps where complete 4 s Spectra are missing, no Entries exist in the File, that is, the Gaps are not Zero-filled or Tagged in any other way. When one or more Channels are missing within a Scan, the missing Measurements are Zero-filled. Data are edited but not calibrated. The Data Numbers in this Data Set can be plotted in raw Form for Event Searches and simple Trend Analysis since they are roughly proportional to the Log of the Electric Field Strength. Calibration Procedures and Tables are provided for use with this Data Set; the use of these is described below.
- Parameters
-
==========
-
Derived Parameters
- ==================
+------------------------------------------------------------+
| Parameter Characteristics | Value |
| Sampling Parameter Name | TIME |
| Sampling Parameter Resolution | 4.0 SECONDS |
| Minimum Sampling Parameter | N/A |
| Maximum Sampling Parameter | N/A |
| Sampling Parameter Interval | 4.0 SECONDS |
| Minimum Available Sampling Interval | 4.0 SECONDS |
| Data Set Parameter Name | PLASMA WAVE SPECTRUM |
| Noise Level | 0.000005 V/M |
| Data Set Parameter Unit | VOLTS/METER |
+------------------------------------------------------------+
Plasma Wave Spectrum: A Set of derived Parameters consisting of Wave Electric Field Intensities or Electric Field Spectral Densities at various contiguous Frequencies over a Range of Frequencies. The MKS Units are: V/m or V^2/(Hz m^2), respectively.
- Measured Parameters
- ===================
Electric Field Component: A measured Parameter equaling the Electric Field Strength (e.g. in mV/m) along a particular Axis Direction.
Wave Magnetic Field Intensity: A measured Parameter equaling the Magnetic Field Strength in a specific Frequency Passband (in MKS Unit: V/m) measured in a single Sensor or Antenna.
Wave Electric Field Intensity: A measured Parameter equaling the Electric Field Strength in a specific Frequency Passband (in MKS Unit: V/m) measured in a single Sensor or Antenna.
The Data Files in this Data Set were created using the 'CDMAKE' Software.
+-----------------------------------------------------+
| Software CDMAKE Characteristics | Value |
| Node ID | PPI-IOWA |
| Software Release Date | 1988-08-01 |
| Cognizant Engineer | LARRY J. GRANROTH |
+-----------------------------------------------------+
CDMAKE is primarily a Data Format Translation Routine which is used to convert Voyager Plasma Wave Spectrometer (PWS) MSF Tape Files to CD Files. The MSF, or Master Science Files, are produced at the University of Iowa as the Primary, ordered, full-information PWS Spectrum Analyzer Data Set. The CD Files contain uncalibrated, full-resolution PWS Data with minimal Ancillary Data in a simplified Format which may be used in CDROM Production.
Note: The Software is not available for Public Use.
- Use of Voyager PWS Calibration Tables
- =====================================
The Voyager PWS Calibration Tables are given in two plain ASCII Text Files named VG1PWSCL.TAB and VG2PWSCL.TAB (for Voyager 1 and Voyager 2, respectively). These provide Information to convert the uncalibrated 'Data Number' output of the PWS sixteen-channel Spectrum Analyzer to calibrated Antenna Voltages for each Frequency Channel. These Calibration Files are always provided with the Data Set when the Data are extracted from PDS by a User. Following is a brief Description of these Files and a Tutorial in their Application.
The first Column lists an uncalibrated Data Number followed by the corresponding Value in calibrated Volts for each of the sixteen Frequency Channels of the PWS Spectrum Analyzer. Each Line contains Calibrations for successive Data Number Values ranging from 0 through 255. (Data Number 0 actually represents the Lack of Data since the Baseline Noise Values for each Channel are all above that.)