This page summarizes information about the selected resource and its origin based on SPASE metadata.

SPASE version 2.0.0

Numerical Data Product: Pioneer_Venus (PVO) hourly merged magnetic field and plasma data

Resource ID

spase://VHO/NumericalData/Pioneer_Venus/MAGandPLS/PT1H

Name

Pioneer_Venus (PVO) hourly merged magnetic field and plasma data

Description

This is an hourly resolution, merged magnetic field and plasma data set created at NSSDC for COHOWeb. Magnetic field vectors and plasma flow direction angles are given in RTN coordinates. Spacecraft position data are given in Heliographic inertial (HGI coordinates).

Additional information

nssdcftp readme

Acknowledgement

Please acknowledge the magnetic field and plasma Principal Investigators, Drs. C.T. Russell and P. Gazis, and NSSDC or GSFC-SPDF

Contact

	Role	Person
1.	Principal investigator	Dr. Christopher T. Russell
2.	Principal investigator	Dr. Paul R. Gazis
3.	General contact	Dr. Natalia E. Papitashvili

Release date

2009-05-20 19:08:29

Repository

Name

SPDF

Availability

Online

Access rights

Open

URL

nssdcftp: for annual files via ftp
COHOWeb plots and lists: Pioneer_Venus-specific page for plots and lists
COHOweb top page: Plots, lists, scatter plots, regressions, distributions, means, etc.

Format

Text

File size

1.2 MB per 1 year

Acknowledgement

Please acknowledge the magnetic field and plasma Principal Investigators, Drs. C.T. Russell and P. Gazis, and NSSDC or GSFC-SPDF

Instruments

Magnetometer (OMAG)

Retarding Potential Analyzer (ORPA)

Measurement type

Magnetic field

Thermal plasma

Temporal description

Start date: 1978-12-05 00:00:00
Stop date: 1992-10-09 00:00:00
Note: Plasma data end on Oct. 9, 1992. Magnetic field data end on Aug. 7, 1988.
Cadence: 1 hour

Observed regions

Heliosphere.Inner

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Parameters

Parameter #1

Name: Year
Parameter key: Column1
Description: Four digit Year
Cadence: 1 hour
Fill value: 999.9999
Parameter type: Temporal

Parameter #2

Name: Day
Parameter key: Column2
Description: Decimal Day of Year
Cadence: 1 hour
Fill value: 999.9999
Parameter type: Temporal

Parameter #3

Name: Hour
Parameter key: Column3
Description: Hour
Cadence: 1 hour
Fill value: 999.9999
Parameter type: Temporal

Parameter #4

Name

PVO Location relative to Venus

Description

Pioneer Venus location relative to the center of Venus, in Venus Solar Orbital coordinates (x from Venus to sun, z northward from Venus orbit plane)

Caveats

The data set contains Venus-centered PVO location in Venus Solar Orbital coordinates. (X from Venus to sun, Z positive northward from Venus orbit plane). This coordinate system is presently not available in the data model. "SSE" (spacecraft solar ecliptic) is used as an approximation. Most if not all heliospheric studies for which hourly data are used, assuming the data were taken as the location of the center of Venus should be fine.

Cadence

1 hour

Units

Coordinate system

Cartesian SSE

Structure

Size

Description

X,Y,Z components

Elements

Index	Name	Component	Parameter key
1	X component	I	Column04
2	Y component	J	Column05
3	Z component	K	Column06

Fill value

9999.9

Parameter type

Positional

Parameter #5

Name: Venus radial distance
Parameter key: Column07
Description: Heliocentric radial distance of Planet Venus in AU
Cadence: 1 hour
Units: AU
Parameter type: Positional

Parameter #6

Name: Venus latitude
Parameter key: Column08
Description: Heliographic Inertial elevation angle of Planet Venus in deg
Cadence: 1 hour
Units: deg
Coordinate system: Spherical HGI
Parameter type: Positional

Parameter #7

Name: Venus longitude
Parameter key: Column09
Description: Heliographic Inertial azimuthal angle of Planet Venus in deg
Cadence: 1 hour
Units: deg
Coordinate system: Spherical HGI
Parameter type: Positional

Parameter #8

Name

Magnetic Field Vector

Description

Hourly averages of XYZ components of fine time scale magnetic field vectors. Coordinate System is Venus Solar Orbital (VSO)

Cadence

1 hour

Units

Structure

Size

Description

X, Y, Z components in Venus Solar Orital (VSO) coordinates

Elements

Index	Name	Component	Parameter key
1	X component	I	Column10
2	Y component	J	Column11
3	Z component	K	Column12

Fill value

999.9999

Quantity

Magnetic field

Qualifier

Vector

Parameter #9

Name

Magnetic Field Vector

Description

Hourly averages of RTN components of fine time scale magnetic field vectors

Cadence

1 hour

Units

Coordinate system

Cartesian RTN

Structure

Size

Description

R,T,N components

Elements

Index	Name	Component	Parameter key
1	R component	I	Column13
2	T component	J	Column14
3	N component	K	Column15

Fill value

999.9999

Quantity

Magnetic field

Qualifier

Vector

Parameter #10

Name: Magnetic Field Magnitude
Parameter key: Column16
Description: Hourly average of fine time scale magnetic field magnitudes
Cadence: 1 hour
Units: nT
Fill value: 999.99
Quantity: Magnetic field
Qualifier: Magnitude

Parameter #11

Name: Flow speed
Parameter key: Column17
Description: Hourly averaged solar wind plasma flow speed
Cadence: 1 hour
Units: km/s
Fill value: 9999.9
Particle type: Proton
Quantity: Flow speed
Qualifier: Average

Parameter #12

Name: Flow elevation angle
Parameter key: Column18
Description: Hourly averaged solar wind plasma flow elevation angle
Cadence: 1 hour
Units: deg
Coordinate system: Spherical RTN
Fill value: 9999.9
Particle type: Proton
Quantity: Flow velocity
Qualifier: Elevation angle

Parameter #13

Name: Flow azimuth angle
Parameter key: Column19
Description: Hourly averaged solar wind plasma flow azimuthal angle
Cadence: 1 hour
Units
Coordinate system: Spherical RTN
Fill value: 9999.9
Particle type: Proton
Quantity: Flow velocity
Qualifier: Azimuth angle

Parameter #14

Name: Density
Parameter key: Column20
Description: Hourly averaged solar wind plasma density
Cadence: 1 hour
Units: n/cc
Fill value: 999.9999
Particle type: Proton
Quantity: Number density
Qualifier: Average

Parameter #15

Name: Temperature
Parameter key: Column21
Description: Hourly averaged solar wind plasma temperature
Cadence: 1 hour
Units: degK
Fill value: 9999999.
Particle type: Proton
Quantity: Temperature
Qualifier: Average

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SPASE version 2.0.0

Instrument: Magnetometer (OMAG)

Instrument ID

spase://SMWG/Instrument/PioneerVenusOrbiter/OMAG

Name

Magnetometer (OMAG)

Alternate name

OMAG

Description

This experiment used a triaxial fluxgate magnetometer with two ring-core sensors at the end of a magnetometer boom and one ring-core sensor, at 45 degrees to the spin axis, halfway down the boom. The drive and electronics design had been used on the Apollo 15 and 16 subsatellites. The objectives of this investigation were to: (1) determine any planetary and remnant magnetic fields; (2) deduce the location and strength of the ionospheric current system; (3) determine the energy and mass balance in the upper atmosphere of Venus; (4) examine the nature of the solar wind interaction with Venus; and, (5) study the near-wake region of Venus and the structure of the Venusian bow shock. Additional objectives for interplanetary (solar wind) studies were to determine the perturbation of the near-planet region by Venus and to compare the properties of the average field at 0.7 and 1.0 AU. The instrument was intended to, in the worst case of low-bit and low-sample rates, measure one vector per 32 s. While in Venus orbit, when the spacecraft was coasting through the interplanetary region in the apoapsis mode, the sample rate was one vector per 8 s. While the spacecraft was passing through Venus' ionosphere in the periapsis mode, the sample rate was four vectors per second. The last full orbit of three-axis data was 3602, which ended on 16 Oct. 1988 at 14:30 UT. After this time, only one-axis data were available.

Additional information

NSSDC's Master Catalog: Information about the Magnetometer (OMAG) experiment on the Pioneer Venus Orbiter mission.

Contact

	Role	Person
1.	General contact	Dr. Christopher T. Russell

Release date

2009-05-20 21:10:14

Instrument type

Magnetometer

Investigation name

Magnetometer (OMAG) on Pioneer Venus Orbiter

Observatory

Pioneer Venus Orbiter

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SPASE version 2.0.0

Instrument: Retarding Potential Analyzer (ORPA)

Instrument ID

spase://SMWG/Instrument/PioneerVenusOrbiter/ORPA

Name

Retarding Potential Analyzer (ORPA)

Alternate name

ORPA

Description

This investigation used a Langmuir-probe retarding-potential analyzer designed to measure electron concentration and temperature, major ion concentrations and temperatures, ion drift velocities, and the energy distribution function of ambient photoelectrons. It was an adaptation of the instrument flown on the German Aeros satellite in 1972. Either one of two sensor heads could be used, each consisting of a multigrid cup and electrometer, which could operate in electron, ion, or photoelectron modes, initiated by spacecraft roll pulses. The measurements taken when the sensor axis was closest to the plasma flow velocity vector were transmitted. The aims of the investigation were to improve knowledge of the important ionic reactions in the Venusian ionosphere, to study the plasma transport processes to determine if Venus has a polar wind, to study the processes at the solar wind-ionosphere boundary, and to study similar aims concerning the ambient electron population.

Additional information

NSSDC's Master Catalog: Information about the Retarding Potential Analyzer (ORPA) experiment on the Pioneer Venus Orbiter mission.

Contact

	Role	Person
1.	General contact	Dr. William C. Knudsen

Release date

2009-05-20 21:10:14

Instrument type

Langmuir Probe

Investigation name

Retarding Potential Analyzer (ORPA) on Pioneer Venus Orbiter

Observatory

Pioneer Venus Orbiter

↑

SPASE version 2.0.0

Observatory: Pioneer Venus Orbiter

Observatory ID

spase://SMWG/Observatory/PioneerVenusOrbiter

Name

Pioneer Venus Orbiter

Alternate name

1978-051A

Pioneer Venus 1

PVO

Pioneer 12

Pioneer Venus 1978 Orbiter

Description

The Pioneer Venus Orbiter was the first of a two-spacecraft orbiter-probe combination designed to conduct a comprehensive investigation of the atmosphere of Venus. The spacecraft was a solar-powered cylinder about 250 cm in diameter with its spin axis spin-stabilized perpendicular to the ecliptic plane. A high-gain antenna was mechanically despun to remain focused on the earth. The instruments were mounted on a shelf within the spacecraft except for a magnetometer mounted at the end of a boom to ensure against magnetic interference from the spacecraft. Pioneer Venus Orbiter measured the detailed structure of the upper atmosphere and ionosphere of Venus, investigated the interaction of the solar wind with the ionosphere and the magnetic field in the vicinity of Venus, determined the characteristics of the atmosphere and surface of Venus on a planetary scale, determined the planet's gravitational field harmonics from perturbations of the spacecraft orbit, and detected gamma-ray bursts. UV observations of comets have also been made. From Venus orbit insertion on December 4, 1978 to July 1980 periapsis was held between 142 and 253 km to facilitate radar and ionospheric measurements. Thereafter, the periapsis was allowed to rise (to 2290 km at maximum) and then fall, to conserve fuel. In 1991 the Radar Mapper was reactivated to investigate previously inaccessible southern portions of the planet. In May 1992 Pioneer Venus began the final phase of its mission, in which the periapsis was held between 150 and 250 km until the fuel ran out and atmospheric entry destroyed the spacecraft the following August. The orbiter cost $125 million to build and operate for the first 10 years. For further details see Colin, L. and Hunten, D. M., Space Science Reviews 20, 451, 1977.

Additional information

NSSDC's Master Catalog: Information about the Pioneer Venus Orbiter mission

Contact

	Role	Person
1.	Project scientist	Dr. Lawrence Colin

Release date

2009-05-20 20:00:12

Observatory group

PIONEER

Location

Region: Heliosphere.Inner; Venus

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Data Description

Table of Contents

Numerical Data Product: Pioneer_Venus (PVO) hourly merged magnetic field and plasma data

Parameters

Parameter #1

Parameter #2

Parameter #3

Parameter #4

Parameter #5

Parameter #6

Parameter #7

Parameter #8

Parameter #9

Parameter #10

Parameter #11

Parameter #12

Parameter #13

Parameter #14

Parameter #15

Instrument: Magnetometer (OMAG)

Instrument: Retarding Potential Analyzer (ORPA)

Observatory: Pioneer Venus Orbiter

Person: Dr. Christopher T. Russell

Person: Dr. Paul R. Gazis

Person: Dr. Natalia E. Papitashvili

Person: Ms. Tamara J. Kovalick

Person: Mr. Robert M. Candey

Person: Dr. Robert E. McGuire

Person: Dr. William C. Knudsen

Person: Dr. Lawrence Colin

Repository: SPDF

	Role	Person
1.	General contact	Ms. Tamara J. Kovalick
2.	Technical contact	Mr. Robert M. Candey
3.	Project scientist	Dr. Robert E. McGuire