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Data Access
FTP access to files at SPDF
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CDAWeb
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
DE 1 8-sec Position Data
var authors='Gurnett, Donald, A.';
document.write(authors);
(2023).
DE 1 8-sec Position Data.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/wma0-gq05. Accessed on document.write(currentDateStr);.
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ResourceID
spase://NASA/NumericalData/DE1/Ephemeris/PT8S
Description
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a lower more circular orbit. The primary objective of the DE program was to investigate magnetosphere-ionosphere-atmosphere coupling processes. The DE mission provided a wealth of new information on a wide variety of magnetospheric plasma wave phenomena including auroral kilometric radiation, auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated with equatorial upper hybrid waves, whistler mode emissions, wave-particle interactions stimulated by ground VLF transmitters, equatorial ion cyclotron emissions, ion Bernstein mode emissions, and electric field turbulence along the auroral field lines. These files contain 8 second resolution emphemeris and spacecraft attitude parameters that coincide with DE-1 telemetry frames containing PWI lowrate data. These parameters are not to be taken as an authoritative set, but are convenient when working with PWI science data products. Most of these data are provided in the Geocentric Equatorial Inertial (GEI) TOD reference frame. The Z axis of the GEI frame is parallel to Earth's spin axis; the X axis points towards the First Point of Aries with the Y axis aligned so as to generate a right-handed coordinate system.
Metadata Rights
CC0-1.0:
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions. The actual data/software may be subject to a different license.
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Details
Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/DE1/Ephemeris/PT8S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
DE 1 8-sec Position Data
AlternateName
Dynamics Explorer 1 8 Second Orbit and Attitude Data
AlternateName
DE-A 8 Second Orbit and Attitude Data
DOI
https://doi.org/10.48322/wma0-gq05
ReleaseDate
2026-07-21 12:04:48Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2023-07-30 12:34:56.789Z
Note
Added DOI and PublicationInfo minted by LFB, metadata versioned up to SPASE 2.6.0, reviewed by LFB 20230727
RevisionEvent
ReleaseDate
2025-05-02 12:34:56.789Z
Note
Added ObservedRegion. JMW.
RevisionEvent
ReleaseDate
2025-10-02 15:11:48Z
Note
Updated PublishedBy name to match ROR Registry. Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB
RevisionEvent
ReleaseDate
2025-12-04 13:29:06Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:16:38Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), PublicationDate, TemporalDescription:TimeSpan:StartDate, TemporalDescription:TimeSpan:StopDate. ZCB
RevisionEvent
ReleaseDate
2026-07-21 12:04:48Z
Note
Added HelioData InformationURL. JWL
Description
Two Dynamics Explorer (DE) spacecraft were launched August 3, 1981, and placed into coplanar polar orbits with DE-1 in a highly elliptical orbit and DE-2 in a lower more circular orbit. The primary objective of the DE program was to investigate magnetosphere-ionosphere-atmosphere coupling processes. The DE mission provided a wealth of new information on a wide variety of magnetospheric plasma wave phenomena including auroral kilometric radiation, auroral hiss, Z mode radiation, narrow-band electromagnetic emissions associated with equatorial upper hybrid waves, whistler mode emissions, wave-particle interactions stimulated by ground VLF transmitters, equatorial ion cyclotron emissions, ion Bernstein mode emissions, and electric field turbulence along the auroral field lines. These files contain 8 second resolution emphemeris and spacecraft attitude parameters that coincide with DE-1 telemetry frames containing PWI lowrate data. These parameters are not to be taken as an authoritative set, but are convenient when working with PWI science data products. Most of these data are provided in the Geocentric Equatorial Inertial (GEI) TOD reference frame. The Z axis of the GEI frame is parallel to Earth's spin axis; the X axis points towards the First Point of Aries with the Y axis aligned so as to generate a right-handed coordinate system.
Acknowledgement
Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication.
PublicationInfo
Authors
Gurnett, Donald, A.
PublicationDate
2023-01-01 00:00:00Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/Donald.A.Gurnett
2.
MetadataContact
spase://SMWG/Person/Jolene.S.Pickett
3.
MetadataContact
spase://SMWG/Person/Larry.J.Granroth
4.
MetadataContact
spase://SMWG/Person/Chris.W.Piker
5.
MetadataContact
spase://SMWG/Person/Lee.Frost.Bargatze
InformationURL
Name
The University of Iowa DE-1 PWI Page
URL
http://www-pw.physics.uiowa.edu/de/home.html
Description
Language
en
InformationURL
Name
HelioData
URL
https://helio.data.nasa.gov/dataset/DE1_Ephemeris_PT8S
Description
The HelioData dataset page provides an overview of the dataset with access links, associated variables, and more.
PriorIDs
spase://VWO/NumericalData/DynamicsExplorer1/Ephemeris/PT8S
spase://VSPO/NumericalData/DynamicsExplorer1/Ephemeris/PT8S
spase://VSPO/NumericalData/DE1/Ephemeris/PT8S
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
FTP access to files at SPDF
URL
ftps://cdaweb.gsfc.nasa.gov/pub/data/de/de1/orbit/or-at_cdaweb/
Description
Direct link to CDF format data via FTP from the SPDF.
AccessURL
Name
HTTP access to files at SPDF
URL
https://cdaweb.gsfc.nasa.gov/pub/data/de/de1/orbit/or-at_cdaweb/
Description
Direct link to CDF format data via HTTP from the SPDF.
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=DE1_PWI_OR-AT&index=sp_phys
ProductKey
DE1_PWI_OR-AT
Description
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb.
Format
CDF
Encoding
None
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/de/de1/orbit/or-at_cdaweb/$Y
AccessFilenameTemplate
de1_pwi_or-at_$Y$m$d_$v.cdf
Acknowledgement
Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication.
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
Availability
Online
AccessRights
Open
AccessURL
Name
CDAWeb Programmatic Data Access
URL
https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/DE1_PWI_OR-AT/clientLibraryExample/
Style
WebService
ProductKey
DE1_PWI_OR-AT
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
Acknowledgement
Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication.
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
CDAWeb HAPI Server
URL
https://cdaweb.gsfc.nasa.gov/hapi
Style
HAPI
ProductKey
DE1_PWI_OR-AT
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
Users of the DE-1 PWI data are encouraged to acknowledge NASA CDAWeb and The University of Iowa as the source of the data in any publication.
ProcessingLevel
Calibrated
InstrumentIDs
spase://SMWG/Instrument/DynamicsExplorer1/Ephemeris
MeasurementType
Ephemeris
TemporalDescription
TimeSpan
StartDate
1981-09-16 05:21:48Z
StopDate
1984-06-28 20:35:55Z
Cadence
PT8S
ObservedRegion
Earth.NearSurface.Ionosphere
ObservedRegion
Earth.Magnetosphere.Plasmasphere
ObservedRegion
Earth.Magnetosphere.Polar
Parameter #1
Name
Epoch
ParameterKey
Epoch
Description
NSSDC standard reference time associated with the start of a PWI SFR sweep
Units
ms
Support
SupportQuantity
Temporal
Parameter #2
Name
GEI Velocity
ParameterKey
GEI_velocity
Description
GEI (Geocentric Equatorial Inertial) Satellite Velocity Vector (km/sec). The order of the vector components is v(x), v(y), v(z).
Units
km/sec
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
SupportQuantity
Velocity
Parameter #3
Name
Altitude
ParameterKey
Altitude
Description
Altitude above a spheroid Earth, not above the geoid.
Units
km
Support
SupportQuantity
Positional
Parameter #4
Name
Geographic Latitude
ParameterKey
GLAT
Description
Geographic latitude of subsatellite point in degrees
Units
degrees
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEO
ValidMin
-90.0
ValidMax
90.0
Support
SupportQuantity
Positional
Parameter #5
Name
Geographic Longitude
ParameterKey
GLON
Description
Geographic longitude of the satellite in degrees
Units
degrees
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEO
ValidMin
-180.0
ValidMax
180.0
Support
SupportQuantity
Positional
Parameter #6
Name
MLT
ParameterKey
MLT
Description
Magnetic Local Time. MLT was defined via the conventional Solar Magnetic frame.
Units
hours
ValidMin
0.0
ValidMax
24.0
Support
SupportQuantity
Positional
Parameter #7
Name
L Shell
ParameterKey
L_Shell
Description
McIlwain's shell parameter (L)
Units
Re
Support
SupportQuantity
Positional
Parameter #8
Name
Invariant Latitude
ParameterKey
ILAT
Description
Current spacecraft field line footprint's geomagnetic latitude.
Units
degrees
ValidMin
-90.0
ValidMax
90.0
Support
SupportQuantity
Positional
Parameter #9
Name
B Magnitude
ParameterKey
B_Magnitude
Description
Magnetic field strength. Any discrepancy between these data and those provided by the magnetometer instrument's own files should be resolved in favor of the latter. See 'Magnetic Field Observations on DE-A and -B', W. H. Farthing, et al., Space Science Instrumentation 5 (1981) for more information.
Units
nT
Field
FieldQuantity
Magnetic
Parameter #10
Name
B Vector (GEI)
ParameterKey
GEI_B_vec
Description
GEI (Geocentric Equatorial Inertial) Magnetic Vector in nanoTesla. The order of the vector components is B(x), B(y), B(z). Any discrepancy between these data and those provided by the magnetometer instrument's own files should be resolved in favor of the latter. See 'Magnetic Field Observations on DE-A and -B', W. H. Farthing, et al., Space Science Instrumentation 5 (1981) for more information.
Units
nT
Field
FieldQuantity
Magnetic
Parameter #11
Name
Orbit Number
ParameterKey
Orbit_Number
Description
The orbit number from PWI archive files.
Support
SupportQuantity
Other
Parameter #12
Name
GEI Rotation
ParameterKey
GEI_rotation
Description
3-by-3 rotation matrix for the transformation from spacecraft coordinates to the GEI frame. The order of the elements is [1,1] = X(x), [1,2] = X(y), [1,3] = X(z), [2,1] = Y(x), [2,2] = Y(y), [2,3] = Y(z), [3,1] = Z(x), [3,2] = Z(y), and [3,3] = Z(z)
Support
SupportQuantity
Positional
Parameter #13
Name
GEI Position
ParameterKey
GEI_Position
Description
Spacecraft position in GEI coordinates, the order of the coordinates is X, Y, Z.
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
SupportQuantity
Positional
Parameter #14
Name
GEI Relative Velocity
ParameterKey
GEI_rel_vel
Description
GEI (Geocentric Equatorial Inertial) Satellite Velocity Vector (km/sec) relative to a rotating atmosphere.
Units
km/sec
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
SupportQuantity
Velocity
Parameter #15
Name
GEI Sun Position
ParameterKey
GEI_sun_pos
Description
GEI (Geocentric Equatorial Inertial) unit vector toward the sun. The order of the components is X, Y, Z.
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
SupportQuantity
Positional
Parameter #16
Name
Spin Phase Angle
ParameterKey
Spin_Angle
Description
Angle between the Velocity Vector and the Spacecraft X-axis
Units
Degrees
ValidMin
-180.0
ValidMax
180.0
Support
SupportQuantity
Positional
Parameter #17
Name
SunFlag
ParameterKey
Sunlight
Description
Sunlight/Darkness flag, 0 = Darkness, 1 = Sunlight
Support
SupportQuantity
Other
Parameter #18
Name
Re
ParameterKey
Re
Description
Geocentric radial distance in Earth Radii. Here 1 Re = 6378.2 km
Units
Re
Support
SupportQuantity
Positional
Parameter #19
Name
Magnetic Latitude
ParameterKey
MLAT
Description
Magnetic latitude in degrees
Units
Degrees
ValidMin
-90.0
ValidMax
90.0
Support
SupportQuantity
Positional