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Data Access
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
THEMIS-D: On Board spin fits (FIT) of Electric (EFI) and Magnetic (FGM) field. On-Board Spin-fit electric and magnetic field data
var authors='Angelopoulos, Vassilis; Bonnell, John, W.; Mozer, Forrest, S.';
document.write(authors);
(2023).
THEMIS-D: On Board spin fits (FIT) of Electric (EFI) and Magnetic (FGM) field. On-Board Spin-fit electric and magnetic field data.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/2acz-ef84. Accessed on document.write(currentDateStr);.
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Copy BibTeX Citation
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ResourceID
spase://NASA/NumericalData/THEMIS/D/Fits/PT3S
Description
THEMIS-D: On Board spin fits of Electric (EFI) and Magnetic (FGM) fields. This file contains data EFI and FGM that has been despun on-board to 3 second resolution. It stores meta information like the number of points that contributed to each spin and the standard deviation of those points. For the EFI data it also stores variables with the Z component of the EFI data zeroed and the Z component of the EFI estimated using the E.B=0 equality. The need to use an estimated Z axis for the EFI is due to error in measurements from the EFI axial booms. These data are provided in DSL (despun spacecraft L-Z vector), GSM, and GSE coordinates.
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/THEMIS/D/Fits/PT3S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
THEMIS-D: On Board spin fits (FIT) of Electric (EFI) and Magnetic (FGM) field. On-Board Spin-fit electric and magnetic field data
DOI
https://doi.org/10.48322/2acz-ef84
ReleaseDate
2025-12-04 13:31:45Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2023-07-30 12:34:56.789
Note
Added DOI and PublicationInfo minted by LFB, metadata versioned up to SPASE 2.6.0, reviewed by LFB 20230727
RevisionEvent
ReleaseDate
2025-09-18 12:34:56.789
Note
Revised ObservedRegion. JMW
RevisionEvent
ReleaseDate
2025-10-03 11:23:59Z
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 13:31:45Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
Description
THEMIS-D: On Board spin fits of Electric (EFI) and Magnetic (FGM) fields. This file contains data EFI and FGM that has been despun on-board to 3 second resolution. It stores meta information like the number of points that contributed to each spin and the standard deviation of those points. For the EFI data it also stores variables with the Z component of the EFI data zeroed and the Z component of the EFI estimated using the E.B=0 equality. The need to use an estimated Z axis for the EFI is due to error in measurements from the EFI axial booms. These data are provided in DSL (despun spacecraft L-Z vector), GSM, and GSE coordinates.
Acknowledgement
NASA contract NAS5-02099 and V. Angelopoulos for use of data from the THEMIS Mission. Specifically: J. W. Bonnell and F. S. Mozer for use of EFI data.
PublicationInfo
Authors
Angelopoulos, Vassilis; Bonnell, John, W.; Mozer, Forrest, S.
PublicationDate
2023-01-01 00:00:00
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/Vassilis.Angelopoulos
2.
CoInvestigator
spase://SMWG/Person/John.W.Bonnell
3.
CoInvestigator
spase://SMWG/Person/Forrest.S.Mozer
4.
MetadataContact
spase://SMWG/Person/Lee.Frost.Bargatze
InformationURL
Name
THEMIS website
URL
https://themis.ssl.berkeley.edu
PriorIDs
spase://VMO/NumericalData/THEMIS-D/Fits/PT3S
spase://VMO/NumericalData/THEMIS/D/Fits/PT3S
spase://VSPO/NumericalData/THEMIS/D/Fits/PT3S
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/themis/thd/l2/fit/
Description
NASA/GSFC CDAWeb ftp access to the data.
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/themis/thd/l2/fit/
Description
In CDF via HTTP from SPDF
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=THD_L2_FIT&index=sp_phys
ProductKey
THD_L2_FIT
Description
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
Format
CDF
Encoding
None
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/themis/thd/l2/fit/$Y
AccessFilenameTemplate
thd_l2_fit_$Y$m$d_$v.cdf
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/THD_L2_FIT/clientLibraryExample/
Style
WebService
ProductKey
THD_L2_FIT
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
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
THD_L2_FIT@0
ProductKey
THD_L2_FIT@1
ProductKey
THD_L2_FIT@2
ProductKey
THD_L2_FIT@3
Description
Web Service to this product using the HAPI interface.
Format
CSV
ProcessingLevel
Calibrated
ProviderProcessingLevel
Level 2
ProviderVersion
Version 01
InstrumentIDs
spase://SMWG/Instrument/THEMIS/D/EFI
spase://SMWG/Instrument/THEMIS/D/FGM
MeasurementType
ElectricField
MeasurementType
MagneticField
TemporalDescription
TimeSpan
StartDate
2008-01-14 17:00:00
RelativeStopDate
-P7D
Cadence
PT3S
ObservedRegion
Heliosphere.NearEarth
ObservedRegion
Earth.Magnetosphere.Magnetotail
ObservedRegion
Earth.Magnetosphere.Main
ObservedRegion
Earth.Magnetosheath
ObservedRegion
Earth.Magnetosphere
ObservedRegion
Earth.Magnetosphere.RadiationBelt
Caveats
The electric field spin plane booms for THEMIS D were not deployed until June 07, 2007 at 1700 UT, any EFI measurements before this date should not be used.
Parameter #1
Name
THEMIS D Fluxgate Magnetometer Spin Fit Deviation
ParameterKey
thd_fgs_sigma
Description
Fluxgate magnetometer on-board instrument measurements are at higher resolution. This parameter stores the standard deviation of the fluxgate magentometer spin fit for each spin resolution element of this data quantity in nT.
Caveats
Calculations of spin-fit for these data are performed on-board.
Cadence
PT3S
Units
nT
UnitsConversion
10e-9>T
ValidMin
0.0
ValidMax
25000.0
FillValue
NaN
Field
Qualifier
StandardDeviation
FieldQuantity
Magnetic
Parameter #2
Name
THEMIS D Fluxgate Magnetometer Spin Fit Data DSL
ParameterKey
thd_fgs_dsl
Description
FGS (spin-fit) magnetic field vector in despun spacecraft coordinates (DSL). To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). These coordinates (DSL) use the Z axis of the spin plane (L Vector), not the probe geometric Z axis.
Caveats
Calculations of spin-fit for these data are performed on-board.
Cadence
PT3S
Units
nT
UnitsConversion
10e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SR2
Structure
Size
3
Description
This structure represents the Magnetic Field Vector B in DSL
Element
Name
Bx DSL FGS-D
Qualifier
Component.I
Index
1
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
By DSL FGS-D
Qualifier
Component.J
Index
2
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Bz DSL FGS-D
Qualifier
Component.K
Index
3
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Magnetic
Parameter #3
Name
THEMIS D Fluxgate Magnetometer Spin Fit Data GSE
ParameterKey
thd_fgs_gse
Description
FGS (spin-fit) magnetic field vector in GSE coordinates. These data are despun. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Then they are converted to GSE on the ground.
Caveats
Calculations of spin-fit for these data are performed on-board.
Cadence
PT3S
Units
nT
UnitsConversion
10e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Description
This structure represents the Magnetic Field Vector B in GSE
Element
Name
Bx GSE FGS-D
Qualifier
Component.I
Index
1
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
By GSE FGS-D
Qualifier
Component.J
Index
2
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Bz GSE FGS-D
Qualifier
Component.K
Index
3
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Magnetic
Parameter #4
Name
THEMIS D Fluxgate Magnetometer Spin Fit Data GSM
ParameterKey
thd_fgs_gsm
Description
FGS (spin-fit) magnetic field vector in GSM coordinates. These data are despun. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Then they are converted to GSM coordinates on the ground.
Caveats
Calculations of spin-fit for these data are performed on-board.
Cadence
PT3S
Units
nT
UnitsConversion
10e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Description
This structure represents the Magnetic Field Vector B in GSM
Element
Name
Bx GSM FGS-D
Qualifier
Component.I
Index
1
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
By GSM FGS-D
Qualifier
Component.J
Index
2
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Bz GSM FGS-D
Qualifier
Component.K
Index
3
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Magnetic
Parameter #5
Name
THEMIS D Fluxgate Magnetometer Spin-Fit Data Times
ParameterKey
thd_fgs_time
Description
Dates/Times for each measurement in seconds since 01-Jan-1970 00:00:00 UTC
Caveats
Unleaped seconds
Cadence
PT3S
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #6
Name
THEMIS D Electric Field Instrument Spin Fit Deviation
ParameterKey
thd_efs_sigma
Description
Electric Field Instrument on-board measurements are at higher resolution. This parameter stores the standard deviation of the electric field instrument spin fit for each spin resolution element of this data quantity in mV/m.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurements should not be considered valid before the deploy date. Z-axis measurements should be treated very carefully. Because the Z-axis booms are much shorter than the spin plane booms, the measurements in the Z-axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
ValidMin
0.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
StandardDeviation
FieldQuantity
Electric
Parameter #7
Name
THEMIS D Electric Field Instrument Spin Fit Data DSL
ParameterKey
thd_efs_dsl
Description
EFS (spin-fit) electric field vector in despun spacecraft coordinates (DSL) To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). These coordinates use the Z axis of the spin plane(L Vector), not the probe geometric Z axis.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. Z-axis measurements should be treated very carefully. Because the Z-axis booms are much shorter than the spin plane booms, the measurements in the Z-axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SR2
Structure
Size
3
Description
This structure represents the Electric Field Vector E in DSL
Element
Name
Ex DSL EFS-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey DSL EFS-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez DSL EFS-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #8
Name
THEMIS D Electric Field Instrument Z=0 Spin-Fit Data DSL
ParameterKey
thd_efs_0_dsl
Description
EFS (spin-fit) electric field vector with Z=0 in despun spacecraft coordinates. (DSL) To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, it has been set to zero in this data quantity. These coordinates use the Z axis of the spin plane(L Vector), not the probe geometric Z axis.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is zeroed for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SR2
Structure
Size
3
Description
This structure represents the Electric Field Vector E in DSL with Z=0
Element
Name
Ex DSL EFS_0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey DSL EFS_0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez DSL EFS_0-D
Qualifier
Component.K
Index
3
ValidMin
-0.0
ValidMax
0.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #9
Name
THEMIS D Electric Field Instrument E dot B = 0 Spin-Fit Data DSL
ParameterKey
thd_efs_dot0_dsl
Description
EFS (spin-fit) electric field vector with E dot B = 0 in despun spacecraft coordinates. (DSL) To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, the value of Ez that makes the dot product of E and B closest to zero is used in this data product, rather than the measured Z value. These coordinates use the Z axis of the spin plane (L Vector), not the probe geometric Z axis.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is estimated for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SR2
Structure
Size
3
Description
This structure represents the Electric Field Vector E in DSL with E dot B = 0
Element
Name
Ex DSL EFS_dot0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey DSL EFS_dot0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez DSL EFS_dot0-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #10
Name
THEMIS D Electric Field Instrument Spin Fit Data GSE
ParameterKey
thd_efs_gse
Description
EFS (spin-fit) electric field vector in GSE coordinates. Data are first despun on-board, then converted to GSE coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec).
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. Z-axis measurements should be treated very carefully. Because the Z-axis booms are much shorter than the spin plane booms, the measurements in the Z-axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSE
Element
Name
Ex GSE EFS-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSE EFS-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSE EFS-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #11
Name
THEMIS D Electric Field Instrument Z=0 Spin-Fit Data GSE
ParameterKey
thd_efs_0_gse
Description
EFS (spin-fit) electric field vector with Z=0 in GSE coordinates. Data are first despun on-board, then converted to GSE coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, it has been set to zero in this data quantity.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is zeroed for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate. The Z-axis is zeroed prior to conversion to GSE coordinates, so the zeroed axis will probably not be colinear with the Z axis of the GSE coordinate system.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSE with Z(dsl)=0
Element
Name
Ex GSE EFS_0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSE EFS_0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSE EFS_0-D
Qualifier
Component.I
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #12
Name
THEMIS D Electric Field Instrument E dot B = 0 Spin-Fit Data GSE
ParameterKey
thd_efs_dot0_gse
Description
EFS (spin-fit) electric field vector with E dot B = 0 in GSE coordinates. Data are first despun on-board, then converted to GSE coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, the value of Ez that makes the dot product of E and B closest to zero is used in this data product, rather than the measured Z value.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is estimated for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate. The Z-axis is estimated prior to conversion to GSE coordinates, so the estimated axis will probably not be colinear with the Z axis of the GSE coordinate system.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSE with E dot B = 0
Element
Name
Ex GSE EFS_dot0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSE EFS_dot0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSE EFS_dot0-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #13
Name
THEMIS D Electric Field Instrument Spin Fit Data GSM
ParameterKey
thd_efs_gsm
Description
EFS (spin-fit) electric field vector in GSM coordinates. Data are first despun on-board, then converted to GSM coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec).
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. Z-axis measurements should be treated very carefully. Because the Z-axis booms are much shorter than the spin plane booms, the measurements in the Z-axis are much more inaccurate.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSM
Element
Name
Ex GSM EFS-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSM EFS-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSM EFS-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #14
Name
THEMIS D Electric Field Instrument Z=0 Spin-Fit Data GSM
ParameterKey
thd_efs_0_gsm
Description
EFS (spin-fit) electric field vector with Z=0 in GSM coordinates. Data are first despun on-board, then converted to GSM coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, it has been set to zero in this data quantity.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is zeroed for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate. The Z-axis is zeroed prior to conversion to GSM coordinates, so the zeroed axis will probably not be colinear with the Z axis of the GSM coordinate system.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSM with Z(dsl)=0
Element
Name
Ex GSM EFS_0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSM EFS_0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSM EFS_0-D
Qualifier
Component.I
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #15
Name
THEMIS D Electric Field Instrument E dot B = 0 Spin-Fit Data GSM
ParameterKey
thd_efs_dot0_gsm
Description
EFS (spin-fit) electric field vector with E dot B = 0 in GSM coordinates. Data are first despun on-board, then converted to GSM coordinates on the ground. To despin, these data are direction corrected using the spin-model and binned down from the cadence of the instrument to the cadence of each spin (3-sec). Since the Z component of the electric field has large error, the value of Ez that makes the dot product of E and B closest to zero is used in this data product, rather than the measured Z value.
Caveats
Calculations of spin-fit for these data are performed on-board. Electric Field Booms for THEMIS D were deployed on June 7, 2007 at 1700 UT. Measurments should not be considered valid before the deploy date. The Z axis is estimated for this quantity because the Z-axis booms are much shorter than the spin plane booms and thus the measurements in the Z axis are much more inaccurate. The Z-axis is estimated prior to conversion to GSM coordinates, so the estimated axis will probably not be colinear with the Z axis of the GSM coordinate system.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Description
This structure represents the Electric Field Vector E in GSM with E dot B = 0
Element
Name
Ex GSM EFS_dot0-D
Qualifier
Component.I
Index
1
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ey GSM EFS_dot0-D
Qualifier
Component.J
Index
2
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Element
Name
Ez GSM EFS_dot0-D
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Field
Qualifier
Vector
FieldQuantity
Electric
Parameter #16
Name
THEMIS D Electric Field Instrument Spin-Fit Data Times
ParameterKey
thd_efs_time
Description
Dates/Times for each measurement in seconds since 01-Jan-1970 00:00:00 UTC
Caveats
Unleaped seconds
Cadence
PT3S
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #17
Name
THEMIS D Fluxgate Magnetometer Spin Fit Model DSL
ParameterKey
thd_fit_bfit
Description
This parameter contains the calibrated fluxgate magnetometer spin model data in despun spacecraft coordinates (DSL). The spin model uses a sine-wave spin model to calculate the spin and despin. These coefficients(A,B,C), the standard deviation(Sigma), and the average value(Avg.) are provided. The equations used for the model are F = Sum(i=1 to N)[E(t_i) - (A + B*sin(omega*t_i)+C*cos(omega*t_i))]^2 , delta F/delta A = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))] , delta F/delta B = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))]-sin(omega*t_i) , delta F/delta C = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))]*cos(omega*t_i) , Gamma = sqrt(F/(N-1)) The system of equations is solved and outliers are removed until no more outliers can be removed.
Caveats
Calculations of spin-fit is performed on-board. The B,C, and Average components of this parameter are very close to the X,Y and Z components(respectively) of the fgs quantity. In this parameter scaling factors are applied, but the data do not have finer calibrations applied. These data are also in despun sensor coordinates, rather than despun spacecraft coordinates. Practically, this means the Z axis is the opposite of the normal DSL coordinate system.
Cadence
PT3S
Units
nT
UnitsConversion
10e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SC
Structure
Size
5
Description
This structure stores the parameters of the FGM spin fit(A,B,C), the standard deviation of the spin fit(Sigma), and the mean of the spin fit(Avg.) as Time by 5 array
Element
Name
A FIT_BFIT FGM-D
Index
1
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
B FIT_BFIT FGM-D
Index
2
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
C FIT_BFIT FGM-D
Index
3
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Sigma FIT_BFIT FGM-D
Index
4
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Avg. FIT_BFIT FGM-D
Index
5
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Field
FieldQuantity
Magnetic
Parameter #18
Name
THEMIS D Fluxgate Magnetometer Spin-Fit Model Times
ParameterKey
thd_fit_bfit_time
Description
Dates/Times for each measurement in seconds since 01-Jan-1970 00:00:00 UTC
Caveats
Unleaped seconds
Cadence
PT3S
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #19
Name
THEMIS D Electric Field Instrument Spin Fit Model DSL
ParameterKey
thd_fit_efit
Description
This parameter contains the calibrated electric field instrument spin model data in despun spacecraft coordinates (DSL). The spin model uses a sine-wave spin model to calculate the spin and despin. These coefficients(A,B,C), the standard deviation(Sigma), and the average value(Avg.) are provided. The equations used for the model are F = Sum(i=1 to N)[E(t_i) - (A + B*sin(omega*t_i)+C*cos(omega*t_i))]^2 , delta F/delta A = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))] , delta F/delta B = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))]-sin(omega*t_i) , delta F/delta C = Sum(i=1 to N)-2*[E(t_i) - (A + B*sin(omega*t_i) + C*cos(omega*t_i))]*cos(omega*t_i) , Gamma = sqrt(F/(N-1)) The system of equations is solved and outliers are removed until no more outliers can be removed.
Caveats
Calculations of spin-fit is performed on-board. The B,C, and Average components of this parameter are very close to the X,Y and Z components(respectively) of the efs quantity. In this parameter scaling factors are applied, but the data do not have finer calibrations applied.
Cadence
PT3S
Units
mV/m
UnitsConversion
10e-3>V/m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SC
Structure
Size
5
Description
This structure stores the parameters of the EFI spin fit(A,B,C), the standard deviation of the spin fit(Sigma), and the mean of the spin fit(Avg.) as Time by 5 array
Element
Name
A FIT_EFIT EFI-D
Index
1
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
B FIT_EFIT EFI-D
Index
2
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
C FIT_EFIT EFI-D
Index
3
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Sigma FIT_EFIT EFI-D
Index
4
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Element
Name
Avg. FIT_EFIT EFI-D
Index
5
ValidMin
-25000.0
ValidMax
25000.0
FillValue
NaN
Field
FieldQuantity
Electric
Parameter #20
Name
THEMIS D Electric Field Instrument Spin-Fit Model Times
ParameterKey
thd_fit_bfit_time
Description
Dates/Times for each measurement in seconds since 01-Jan-1970 00:00:00 UTC
Caveats
Unleaped seconds
Cadence
PT3S
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal