An official website of the United States government
Here's how you know v
Official websites use .gov
A .gov websites belongs to an official government organization in the United States
Secure .gov website use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Data Access
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
DE 1 Plasma Wave Instrument (PWI) Step Frequency Correlator Electric and Magnetic Field Spectral Density
var authors='Gurnett, Donald, A.';
document.write(authors);
(2023).
DE 1 Plasma Wave Instrument (PWI) Step Frequency Correlator Electric and Magnetic Field Spectral Density.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/cb14-a164. Accessed on document.write(currentDateStr);.
Note: Proper references, including
Copy BibTeX Citation
or other formats, should include the "Accessed on date" to identify the version of the resource being cited in a given publication.
ResourceID
spase://NASA/NumericalData/DE1/PWI/SFC/PT0.25S
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 calibrated, full resolution, data from the DE-1 Plasma Wave Instrument (PWI). This instrument was designed and built by the plasma wave group at The University of Iowa, Department of Physics and Astronomy, in collaboration with investigators at Stanford University's STAR Laboratory. It measured plasma wave phenomena and quasi-static electric fields using paired combinations of five PWI sensors: a 200m tip-to-tip long wire electric antenna deployed in the spacecraft spin plane, a 9m tip-to-tip tubular electric antenna deployed along the spacecraft spin axis, a short 0.6m electric antenna, mounted on the boom and oriented parallel to the long wire antenna, a magnetic loop antenna mounted on the boom and oriented to measure the component of the magnetic field parallel to the long wire antenna, and a magnetic search coil antenna, also mounted on a boom and oriented to measure the magnetic field parallel to the spacecraft spin axis. The PWI main electronics unit consisted of a Step Frequency Correlator (SFC), a Low Frequency Correlator (LFC), a Wideband Analog Receiver (WBR) and a Linear Wave Receiver (LWR). Only the SFC data are included in these files. The LFC data were provided in a companion fileset. A dataset containing available high rate WBR LWR data may be provided in the future. The SFC consisted of two Step Frequency Receivers (SFR-A and SFR-B) which provided amplitude measurements of the electric and magnetic fields from 100 Hz to 400 kHz and in-phase and quadrature-phase correlations of signals from any selected antenna pair. Phase data are not provided in these datasets.
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.
View XML |
Edit
Details
Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/DE1/PWI/SFC/PT0.25S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
DE 1 Plasma Wave Instrument (PWI) Step Frequency Correlator Electric and Magnetic Field Spectral Density
AlternateName
Dynamics Explorer 1 PWI SFC Spectra
AlternateName
DE-A PWI SFC Spectra
DOI
https://doi.org/10.48322/cb14-a164
ReleaseDate
2026-06-26 13:16:40Z
RevisionHistory
RevisionEvent
ReleaseDate
2020-07-07 21:14:31Z
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
2023-10-09 12:34:56.789Z
Note
Added complete CDAWeb and HAPI AccessInformation, LFB 20231009
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 13:16:40Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), PublicationDate, TemporalDescription:TimeSpan:StartDate, TemporalDescription:TimeSpan:StopDate. ZCB
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 calibrated, full resolution, data from the DE-1 Plasma Wave Instrument (PWI). This instrument was designed and built by the plasma wave group at The University of Iowa, Department of Physics and Astronomy, in collaboration with investigators at Stanford University's STAR Laboratory. It measured plasma wave phenomena and quasi-static electric fields using paired combinations of five PWI sensors: a 200m tip-to-tip long wire electric antenna deployed in the spacecraft spin plane, a 9m tip-to-tip tubular electric antenna deployed along the spacecraft spin axis, a short 0.6m electric antenna, mounted on the boom and oriented parallel to the long wire antenna, a magnetic loop antenna mounted on the boom and oriented to measure the component of the magnetic field parallel to the long wire antenna, and a magnetic search coil antenna, also mounted on a boom and oriented to measure the magnetic field parallel to the spacecraft spin axis. The PWI main electronics unit consisted of a Step Frequency Correlator (SFC), a Low Frequency Correlator (LFC), a Wideband Analog Receiver (WBR) and a Linear Wave Receiver (LWR). Only the SFC data are included in these files. The LFC data were provided in a companion fileset. A dataset containing available high rate WBR LWR data may be provided in the future. The SFC consisted of two Step Frequency Receivers (SFR-A and SFR-B) which provided amplitude measurements of the electric and magnetic fields from 100 Hz to 400 kHz and in-phase and quadrature-phase correlations of signals from any selected antenna pair. Phase data are not provided in these datasets.
Acknowledgement
Users of the DE-1 PWI SFC 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
https://space.physics.uiowa.edu/plasma-wave/de/home.html
Description
Language
en
PriorIDs
spase://VWO/NumericalData/DynamicsExplorer1/PWI/SFC.PT0.25S
spase://VSPO/NumericalData/DynamicsExplorer1/PWI/SFC/PT0.25S
spase://VSPO/NumericalData/DE1/PWI/SFC/PT0.25S
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
FTPS from SPDF (not with most browsers)
URL
ftps://spdf.gsfc.nasa.gov/pub/data/de/de1/waves_pwi/sfc-spectra_cdaweb/
ProductKey
DE1_PWI_SFC-SPECTRA
Description
In CDF via ftps from SPDF
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/de/de1/waves_pwi/sfc-spectra_cdaweb/
ProductKey
DE1_PWI_SFC-SPECTRA
Description
In CDF via https from SPDF
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=DE1_PWI_SFC-SPECTRA&index=sp_phys
ProductKey
DE1_PWI_SFC-SPECTRA
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/waves_pwi/sfc-spectra_cdaweb/$Y
AccessFilenameTemplate
de1_pwi_sfc-spectra_$Y$m$d_$v.cdf
Acknowledgement
Users of the DE-1 PWI SFC 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_SFC-SPECTRA/clientLibraryExample/
Style
WebService
ProductKey
DE1_PWI_SFC-SPECTRA
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 SFC 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_SFC-SPECTRA
Description
Web Service to this product using the HAPI interface
Format
CSV
Acknowledgement
Users of the DE-1 PWI SFC 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/PWI
MeasurementType
Waves.Passive
MeasurementType
Spectrum
TemporalDescription
TimeSpan
StartDate
1981-09-16 05:21:48Z
StopDate
1984-06-28 20:35:55Z
Cadence
PT0.25S
ObservedRegion
Earth.NearSurface.Ionosphere
ObservedRegion
Earth.Magnetosphere.Plasmasphere
ObservedRegion
Earth.Magnetosphere.Polar
Parameter #1
Name
Event time for the start of the sweep
ParameterKey
Epoch
Description
Spacecraft Event Time in UTC for the start of an SFR sweep. To get time offsets within a sweep add the corresponding values in the SubSweepTime array.
Support
SupportQuantity
Temporal
Parameter #2
Name
SFC Ex Receiver (1=A,2=B,3=both)
ParameterKey
Ex_Receivers
Description
Step Frequency Correlator has two independent Step Frequency Receivers, labeled 'A' and 'B'. This variable records which of the SFRs were connected to the Ex antenna during the collection of each record. This field will read: '1' if SFR-A was connected to Ex, '2' if SFR-B was connected to Ex, and '3' if both were used at different times during the 32 second sweep period.
Support
SupportQuantity
Other
Parameter #3
Name
SFC Es Receiver (1=A,2=B,3=both)
ParameterKey
Es_Receivers
Description
Step Frequency Correlator has two independent Step Frequency Receivers, labeled 'A' and 'B'. This variable records which of the SFRs were connected to the Es antenna during the collection of each record. This field will read: '1' if SFR-A was connected to Es, '2' if SFR-B was connected to Es, and '3' if both were used at different times during the 32 second sweep period.
Support
SupportQuantity
Other
Parameter #4
Name
SFC Ez Receiver (1=A,2=B,3=both)
ParameterKey
Ez_Receivers
Description
Step Frequency Correlator has two independent Step Frequency Receivers, labeled 'A' and 'B'. This variable records which of the SFRs were connected to the Ez antenna during the collection of each record. This field will read: '1' if SFR-A was connected to Ez, '2' if SFR-B was connected to Ez, and '3' if both were used at different times during the 32 second sweep period.
Support
SupportQuantity
Other
Parameter #5
Name
SFC B Receiver (1=A,2=B,3=both)
ParameterKey
B_Receivers
Description
Step Frequency Correlator has two independent Step Frequency Receivers, labeled 'A' and 'B'. This variable records which of the SFRs were connected to the B antenna during the collection of each record. This field will read: '1' if SFR-A was connected to B, '2' if SFR-B was connected to B, and '3' if both were used at different times during the 32 second sweep period.
Support
SupportQuantity
Other
Parameter #6
Name
Integer combining all data quality flags (0 = no issues detected)
ParameterKey
Quality_Flag
Description
A bitwise OR'ing of all known issue values for this record. The following issue values are defined. (0x2: Attenuation Mode) If this value is present the measurements are less sensitive than normal due to the input being attenuated by 30 dB. Though the data are still calibrated they do not have the same contrast as data collected in the un-attenuated state. (0x1: Gain Toggle Mode) If this value is present it means that the SFC was toggling attenuation states every 1/2 second. Measurements collected in the first half of the second are not attenuated. Measurements collected in the last half were attenuated by 30 dB. To achieve a single calibrated state for a single filter band in a record the attenuated measurements have been dropped. The final quality flag is a bitwise OR'ing of all issue values.
Support
SupportQuantity
Other
Parameter #7
Name
Spin Plane E-Field (SFC Ex) Spectra, 200 meter antenna, 104 Hz to 409 kHz
ParameterKey
Ex_Spectra
Description
These data are collected via the Long Wire Antenna (Ex) which has a frequency response range of DC to 2 MHz. It is constructed of two 100 meter wires deployed in the spacecraft spin plane held in place by a 5 g tip mass. The conductor is made of BeCu wire with 7 strands of 5-mil diam each. The effective electrical length is 173.1 meters DC and 101.4 meters AC.
Units
V^2 m^-2 Hz^-1
Structure
Size
512
Wave
WaveType
PlasmaWaves
WaveQuantity
ACElectricField
FrequencyRange
SpectralRange
RadioFrequency
Low
104
High
409000
Units
Hz
Parameter #8
Name
Spin Axis E-Field (SFC Ez) Spectra, 8 meter antenna, 104 Hz to 409 kHz
ParameterKey
Ez_Spectra
Description
These data are collected via the Tubular Electric Antenna (Ez) which has a frequency response range of DC to 2 MHz. It is constructed of two 4 meter tubes deployed along the spacecraft spin axis. The conductor is silver plated BeCu 2.8 cm diameter elements and has an effective electrical length of 8.0 meters DC and 5.0 meters AC.
Units
V^2 m^-2 Hz^-1
Structure
Size
512
Wave
WaveType
PlasmaWaves
WaveQuantity
ACElectricField
FrequencyRange
SpectralRange
RadioFrequency
Low
104
High
409000
Units
Hz
Parameter #9
Name
Spin Plane E-Field (SFC Es) Spectra, 0.6 meter antenna, 104 Hz to 100 kHz
ParameterKey
Es_Spectra
Description
These data are collected via the Short Electric Antenna (Es) which has a response range of 20 Hz to 100 kHz. It's constructed of two 10 cm diameter wire spheres separated by 0.6 meters with fiberglass booms. It is mounted on the PWI 6 meter boom oriented parallel to the long wire antenna (Ex). It's effective electrical length is 0.6 meters for AC signals.
Units
V^2 m^-2 Hz^-1
Structure
Size
512
Wave
WaveType
PlasmaWaves
WaveQuantity
ACElectricField
FrequencyRange
SpectralRange
RadioFrequency
Low
104
High
100000
Units
Hz
Parameter #10
Name
Spin Plane B-Field Spectra (SFC B), 1.0 m^2 loop, 104 Hz to 409 kHz
ParameterKey
B_Spectra
Description
These data are collected via the Magnetic Loop Antenna (B) which has a frequency response range of 100 Hz to 35 kHz for dB/dt and 35 kHz to 400 kHz response for B. It is constructed of a single loop of aluminum tubing of 0.8 by 1.25 meters in size covering 1.0 m^2 area and is mounted on the PWI 6 meter boom oriented to measure the spin-modulated component of B parallel to the long wire antenna, Ex.
Units
nT^2 Hz^-1
Structure
Size
512
Wave
WaveType
PlasmaWaves
WaveQuantity
ACMagneticField
FrequencyRange
SpectralRange
RadioFrequency
Low
104
High
409000
Units
Hz
Parameter #11
Name
Time offsets from the Epoch time for each spectra measurement in a sweep
ParameterKey
SubSweepTime
Description
If sub-sweep timing is not important to your application, this value can be ignored. Otherwise for each measurement add this time to the Epoch value for the record. There is one offset in this array for each measurement in the sweep
Units
s
Support
SupportQuantity
Temporal
Parameter #12
Name
Channel Frequency Centers (fixed), 512 (104.8 to 409610 Hz)
ParameterKey
Frequencies
Description
The SFC contained two Filter Receivers, SFR-A and SFR-B; this variable provides frequency channel centers for the two receivers. The same table is used for both SFR-A and SFR-B data.
Units
Hz
Support
SupportQuantity
Other
Parameter #13
Name
Wideband (waveform) data availability status
ParameterKey
WBR_xmit
Description
PWI Waveform data were transmitted directly from DE1 without going through the standard telemetry stream. This status field will read 0 if the wideband transmitter was off during this time period and thus waveform data were not transmitted. A 1 in this field indicates the transmitter was on and that waveform data may be available.
Support
SupportQuantity
Other