Data Set Information
|
| DATA_SET_NAME |
PVO VENUS EFD BROWSE ELECTRIC FIELD 24SEC AVGS V1.0
|
| DATA_SET_ID |
PVO-V-OEFD-4--EFIELD-24SEC-V1.0
|
| NSSDC_DATA_SET_ID |
|
| DATA_SET_TERSE_DESCRIPTION |
|
| DATA_SET_DESCRIPTION |
This data set contains wave electric field amplitudes measuredat four different frequencies by the Pioneer Venus Orbiter ElectricField Detector. The data are averaged over 24 second intervals on 12second centers. Each averaging interval contains both the minimumamplitude, average amplitude and peak amplitude for that interval ateach of the four frequencies. The four frequencies are 100 Hz,730 Hz, 5.4 kHz, 30 kHz. The frequency filters are narrow-band,with a 30% bandwidth. Thus wave amplitudes are given in V/m/root(Hz).The filters are continuously active, but data are only provided at arate determined by the spacecraft telemetry rate. The wave antennais oriented perpendicular to the spacecraft spin axis, and so the waveinstrument measures only wave fields in the spacecraft spin plane.The wave antenna is a small Y-shaped structure, with effectiveseparation of 0.76 meters. The Electric field data file contains the following information:RECORD LENGTH = 56NUMBER OF COLUMNS = 13OPERATING SYSTEM = SUN/UNIX # NAME UNITS SOURCE DESCRIPTION001 UT SECONDS PVO002 E100HZMX V/M/HZ.5 PVO EFD 2 spin max003 E100HZAV V/M/HZ.5 PVO EFD 2 spin ave004 E100HZMN V/M/HZ.5 PVO EFD 2 spin min005 E730HZMX V/M/HZ.5 PVO EFD 2 spin max006 E730HZAV V/M/HZ.5 PVO EFD 2 spin ave007 E730HZMN V/M/HZ.5 PVO EFD 2 spin min008 E5.4KHZMX V/M/HZ.5 PVO EFD 2 spin max009 E5.4KHZAV V/M/HZ.5 PVO EFD 2 spin ave010 E5.4KHZMN V/M/HZ.5 PVO EFD 2 spin min011 E30KHZMX V/M/HZ.5 PVO EFD 2 spin max012 E30KHZAV V/M/HZ.5 PVO EFD 2 spin ave013 E30KHZMN V/M/HZ.5 PVO EFD 2 spin minMISSING DATA FLAG = 1.000000E+32AVERAGE INTERVAL = 00:00:24.000 There is also a file available that contains ephemerisdata. This is located in the directory /DATA/EPHEM andhas the following information:RECORD LENGTH = 64NUMBER OF COLUMNS = 15OPERATING SYSTEM = SUN/UNIX # NAME UNITS SOURCE DESCRIPTION001 UTIME SECONDS PVO002 X VSO RV PVO SEDR Position X003 Y VSO RV PVO SEDR Position Y004 Z VSO RV PVO SEDR Position Z005 ALT KM PVO SEDR Altitude006 SZA DEG PVO SEDR Solar Zenith Angle007 PLONG DEG PVO SEDR Planetary longitude008 PLAT DEG PVO SEDR Planetary latitude009 SPX VSO PVO SEDR Spin axis X010 SPY VSO PVO SEDR Spin axis Y011 SPZ VSO PVO SEDR Spin axis Z012 CLAT DEG PVO SEDR Celestial latitude013 CLONG DEG PVO SEDR Celestial longitude014 ELONG DEG PVO SEDR Earth celestial longitude015 RSUN AU PVO SEDR Distance to the SunMISSING DATA FLAG = 1.000000E+32AVERAGE INTERVAL = 00:00:12.000 Other ancillary data products are available. A filecontaining phase and offset data is located in the directory/DATA/PHASEOFF. It contains the following information:RECORD LENGTH = 56NUMBER OF COLUMNS = 13OPERATING SYSTEM = SUN/UNIX # NAME UNITS SOURCE DESCRIPTION001 UT SECONDS PVO002 E100 PH DEG PVO EFD Modulation phase003 E100 AMP V/M/HZ.5 PVO EFD Modulation amplitude004 E730 PH DEG PVO EFD Modulation phase005 E730 AMP V/M/HZ.5 PVO EFD Modulation amplitude006 E5.4KPH DEG PVO EFD Modulation phase007 E5.4KAMP V/M/HZ.5 PVO EFD Modulation amplitude008 E30K PH DEG PVO EFD Modulation phase009 E30K AMP V/M/HZ.5 PVO EFD Modulation amplitude010 TAV NT PVO MAG Average T sensor offset011 GDIFFX NT PVO MAG S/C field G correction X012 GDIFFY NT PVO MAG S/C field G correction Y013 GDIFFZ NT PVO MAG S/C field G correction ZMISSING DATA FLAG = 1.000000E+32AVERAGE INTERVAL = 00:00:24.000 A file containing engineering data is located in the directory/DATA/ENGR. It contains the following information:RECORD LENGTH = 64NUMBER OF COLUMNS = 14OPERATING SYSTEM = SUN/UNIX # NAME UNITS SOURCE DESCRIPTION001 UT SECONDS PVO002 ElecT DEG PVO MAG Electronics temperature003 PsensT DEG PVO MAG P&T sensor temperature004 GsensT DEG PVO MAG G sensor temperature005 MODE 1:2:3 PVO MAG Fast Normal or Gradiometer006 SMPLRATE 1 or 3 PVO MAG Sample format007 CAL 0 or 1 PVO MAG Calibration008 SAS 1:2:4 PVO MAG Spin average select009 FORMAT 0-15 PVO EDR TLM data format010 BITRAT BITS/S PVO EDR Bit rate011 SPIN SECONDS PVO SEDR Spin period012 TFS SECONDS PVO SEDR Pulse time013 SMINR SECONDS PVO SEDR Sun-RIP difference014 PTFLAG PVO SEDR Pulse Time flagMISSING DATA FLAG = 1.000000E+32 FORMAT: 0:ENG,1:UNK,2:UNK,3:PGM,4:ACS,5:CMRO,6:PYBK,7:DMRO,8:LACR, 9:PERA,10:PERB,11:PERC,12:PERD,13:PERE,14:APOA,15:APOB A file containing instrument status information is located in thedirectory /DATA/INSTSTAT. It contains the following information:RECORD LENGTH = 56NUMBER OF COLUMNS = 13OPERATING SYSTEM = SUN/UNIX # NAME UNITS SOURCE DESCRIPTION001 UT SECONDS PVO002 PCOS NT PVO MAG Norm(P cos amp)003 PSIN NT PVO MAG Norm(P sin amp)004 DX NT PVO MAG Norm(Tsin-Gcos)005 DY NT PVO MAG Norm(Gsin+Tcos)006 DZ NT PVO MAG Norm(Gdc-Pdc)007 RAMP PVO MAG S2xy / S1xy008 DPHS DEG PVO MAG Phase S2 - S1009 DC1 NT PVO MAG DC of S1010 DC2 NT PVO MAG DC of S2011 ZCOS NT PVO MAG Cos amp of Z sens012 ZSIN NT PVO MAG Sin amp of Z sens013 ZDC NT PVO MAG DC amp of Z sensMISSING DATA FLAG = 1.000000E+32AVERAGE INTERVAL = 00:00:24.000
|
| DATA_SET_RELEASE_DATE |
1993-06-30T00:00:00.000Z
|
| START_TIME |
1978-12-05T07:20:07.282Z
|
| STOP_TIME |
1992-10-08T04:30:23.299Z
|
| MISSION_NAME |
PIONEER VENUS
|
| MISSION_START_DATE |
1968-06-01T12:00:00.000Z
|
| MISSION_STOP_DATE |
1992-10-07T12:00:00.000Z
|
| TARGET_NAME |
VENUS
|
| TARGET_TYPE |
PLANET
|
| INSTRUMENT_HOST_ID |
PVO
|
| INSTRUMENT_NAME |
PLASMA WAVE ANALYZER
|
| INSTRUMENT_ID |
OEFD
|
| INSTRUMENT_TYPE |
PLASMA WAVE
|
| NODE_NAME |
planetary plasma interactions
|
| ARCHIVE_STATUS |
ARCHIVED
|
| CONFIDENCE_LEVEL_NOTE |
The instrument noise level (and hence sensitivity) is determinedby the ambient environment at the time of observation. Photo-electrons emitted from various spacecraft surfaces appear to bea strong source of electric field interference. As a consequencedata acquired when the spacecraft is in sunlight often are contaminatedby spin modulated interference, especially when the spacecraft isin the low density solar wind, where the Debye length is severalmeters. The noise is usually lowest when the antenna elementsare in the spacecraft shadow. The noise level is also reducedwhen the spacecraft is deep within the dayside ionosphere,where the Debye length is much smaller than the antenna size.The noise is not present when the spacecraft is within theoptical shadow of the planet. In this case, however, additionalnoise features are observed (mainly at 100 Hz) when thespacecraft is at low altitude within the nightside ionosphere. Thisinterference is readily discriminated in the high resolution data,where the noise is present as a sharp pulse occurring twice perspin.The averaging scheme used can be subject to temporal aliasing whenthe data rate is sufficiently low, such that only one or two dataare obtained per 24 second interval. Since the sampling intervaland spin period are not exactly synchronized, periodic noise signals,such as the interference, are aliased by the low sampling frequency.In this case the data display periodic structure, but with a periodmuch longer than the spin period.The instrument was calibrated in air. No attempt to incorporatechanges in antenna-plasma coupling due to changes in Debyelength have been included in the data processing.
|
| CITATION_DESCRIPTION |
Kniffin, M., PVO-V-OEFD-4--EFIELD-24SEC-V1.0, PVO VENUS EFD BROWSE ELECTRIC FIELD 24SEC AVGS V1.0, NASA Planetary Data System, 1993.
|
| ABSTRACT_TEXT |
This data set contains wave electricfield amplitudes measured at four different frequencies by the Pioneer VenusOrbiter Electric Field Detector. The data are averaged over 24 secondintervals on 12 second centers. Each averaging interval contains both theminimum amplitude, average amplitude and peak amplitude for that interval ateach of the four frequencies. The four frequencies are 100 Hz,730 Hz, 5.4 kHz, 30 kHz. The frequency filters are narrow-band,with a 30% bandwidth. Thus wave amplitudes are given in V/m/root(Hz).The filters are continuously active, but data are only provided at arate determined by the spacecraft telemetry rate. The wave antennais oriented perpendicular to the spacecraft spin axis, and so the waveinstrument measures only wave fields in the spacecraft spin plane.The wave antenna is a small Y-shaped structure, with effectiveseparation of 0.76 meters.
|
| PRODUCER_FULL_NAME |
MURIEL KNIFFIN
|
| SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
|
|
.png)
.png)
