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Voyager 1 Hourly Magnetic Field Data from 1990-2004

ResourceID
spase://NASA/NumericalData/Voyager1/MAG/1990/PT1H

Description

This data set contains hour averages of the interplanetary magnetic field (IMF) measurements obtained by the triaxial fluxgate magnetometer (MAG) experiment on Voyager 1. Identical instruments on Voyager 1 and 2 were designed to measure the IMF between Earth and Saturn (10 AU) during the primary Voyager mission. The design and performance yielded absolute accuracies to better than 0.1 nT. In general, each component of the IMF hourly average has an uncertainty of up to (+/- 0.05 nT) in the region beyond 10 AU. More accurate measurements can be obtained by special processing of the data, but it was not feasible to do this for the entire data set included here. The magnetic field magnitude in nT is provided along with angles of the field vector in the spacecraft-centered Heliographic (HG) coordinate system, also known as RTN. The X-HG axis is directed from the Sun to the spacecraft, Y-HG is the cross product of the solar rotation axis and X-HG, and Z-HG completes the orthogonal axis system. The accompanying format description file defines the transformation of the HG angles to vector components. Cartesian coordinates are given for the spacecraft in the sun-centered Inertial Heliographic (IHG) system, where the Z-IHG axis is parallel to the solar rotation axis, X-IHG points towards the ascending node direction of the solar equator's intersection with the Ecliptic, and Y-IHG is parallel to the solar equator and completes the orthogonal system. The MAG instruments are described by K. W. Behannon et al., Space Science Reviews, 21, 235, 1977. The data and coordinates are described by L. F. Burlaga, Space Science Reviews, 39, 255, 1984. These data are from 1990-2004 and do not include spacecraft position data whereas the 1977-1989 data do. The seperation into two data products resulted from the fact that mean fields were falling towards the instrumentation digitization resolution. The Voyager/MAG team temporarily stopped production while they addressed the issue. Subsequent production in 1990 resulted in a similar data set, but without the spacecraft position. This data set is also related to the 1-hour merged Voyager mag and plasma data set. These associations are listed below using the SPASE AssociationID notation.

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Details

Version:2.2.9

NumericalData

ResourceID
spase://NASA/NumericalData/Voyager1/MAG/1990/PT1H
ResourceHeader
ResourceName
Voyager 1 Hourly Magnetic Field Data from 1990-2004
ReleaseDate
2021-03-11 18:39:11Z
Description

This data set contains hour averages of the interplanetary magnetic field (IMF) measurements obtained by the triaxial fluxgate magnetometer (MAG) experiment on Voyager 1. Identical instruments on Voyager 1 and 2 were designed to measure the IMF between Earth and Saturn (10 AU) during the primary Voyager mission. The design and performance yielded absolute accuracies to better than 0.1 nT. In general, each component of the IMF hourly average has an uncertainty of up to (+/- 0.05 nT) in the region beyond 10 AU. More accurate measurements can be obtained by special processing of the data, but it was not feasible to do this for the entire data set included here. The magnetic field magnitude in nT is provided along with angles of the field vector in the spacecraft-centered Heliographic (HG) coordinate system, also known as RTN. The X-HG axis is directed from the Sun to the spacecraft, Y-HG is the cross product of the solar rotation axis and X-HG, and Z-HG completes the orthogonal axis system. The accompanying format description file defines the transformation of the HG angles to vector components. Cartesian coordinates are given for the spacecraft in the sun-centered Inertial Heliographic (IHG) system, where the Z-IHG axis is parallel to the solar rotation axis, X-IHG points towards the ascending node direction of the solar equator's intersection with the Ecliptic, and Y-IHG is parallel to the solar equator and completes the orthogonal system. The MAG instruments are described by K. W. Behannon et al., Space Science Reviews, 21, 235, 1977. The data and coordinates are described by L. F. Burlaga, Space Science Reviews, 39, 255, 1984. These data are from 1990-2004 and do not include spacecraft position data whereas the 1977-1989 data do. The seperation into two data products resulted from the fact that mean fields were falling towards the instrumentation digitization resolution. The Voyager/MAG team temporarily stopped production while they addressed the issue. Subsequent production in 1990 resulted in a similar data set, but without the spacecraft position. This data set is also related to the 1-hour merged Voyager mag and plasma data set. These associations are listed below using the SPASE AssociationID notation.

Acknowledgement
Use of these data in publications should be accompanied at minimum by acknowledgements of the National Space Science Data Center and the Principal Investigator Norman Ness.
Contacts
RolePersonStartDateStopDateNote
1.PrincipalInvestigatorspase://SMWG/Person/Norman.F.Ness
InformationURL
Association
AssociationID
AssociationType
PartOf
Association
AssociationID
AssociationType
PartOf
PriorIDs
spase://VHO/NumericalData/Voyager1/MAG/1990.PT1H
spase://VSPO/NumericalData/Voyager1/MAG/1990/PT1H
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Format
Text.ASCII
InstrumentIDs
MeasurementType
MagneticField
TemporalDescription
TimeSpan
StartDate
1990-01-01 00:00:00
StopDate
2004-12-31 23:59:59
Cadence
PT1H
ObservedRegion
Heliosphere.NearEarth
ObservedRegion
Heliosphere.Outer
Parameter #1
Name
Spacecraft ID
ParameterKey
Column_1
Description

1 = Voyager-1, 2 = Voyager-2

Support
SupportQuantity
Other
Parameter #2
Name
Year
ParameterKey
Column_2
Description

Decimal Year

Support
SupportQuantity
Temporal
Parameter #3
Name
F1 Mag
ParameterKey
Column_3
Description

Magnetic Field Magnitude computed from high-resolution observations

CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
HG
Field
Qualifier
Magnitude
FieldQuantity
Magnetic
Parameter #4
Name
Elevation Angle
ParameterKey
Column_4
Description

Elevation Angle (degrees) in heliographic coordinates

Units
degrees
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
HG
Field
Qualifier
DirectionAngle
FieldQuantity
Magnetic
Parameter #5
Name
Azimuthal Angle
ParameterKey
Column_5
Description

Azimuthal Angle (degrees) in heliographic coordinates

Units
degrees
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
HG
Field
Qualifier
DirectionAngle
FieldQuantity
Magnetic
Parameter #6
Name
F2 Magnitude
ParameterKey
Column_6
Description

The magnetic field strength, F2, computed from the hour averages of the components. The components of B can be computed from F2 and the two angles.

CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
HG
Field
Qualifier
Magnitude
FieldQuantity
Magnetic