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THEMIS-B Level 1 Probe State Data

ResourceID
spase://NASA/NumericalData/THEMIS/B/Ephemeris/PT01M

Description

The L1 STATE files contain the following data, sampled at one-minute intervals:

           * probe position and velocity in GEI, GSE, and GSM coordinates;
           * flags to indicate regions of interest and maneuver status;
           * RA and declination of spin axis;
           * spin period and spin phase;
           * spin model parameters for high-precision interpolation of spin phase between one-minute data points.

           Version number indicates data source as follows:

           * V00: predicted ephemeris and attitude, no spin period or spin phase;
           * V01: predicted ephemeris and attitude, spin period and spin phase derived from probe telemetry;
           * V02: predicted attitude, definitive ephemeris from magnetometer and Doppler tracking data;
           * V03: corrected attitude and spin phase derived from fully calibrated magnetometer data. (added science attitude determination using perigee data post-processing).

           Produced by Mission Ops, Science Ops and Science Team.

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Details

Version:2.3.2

NumericalData

ResourceID
spase://NASA/NumericalData/THEMIS/B/Ephemeris/PT01M
ResourceHeader
ResourceName
THEMIS-B Level 1 Probe State Data
ReleaseDate
2021-04-27 15:38:11Z
Description

The L1 STATE files contain the following data, sampled at one-minute intervals:

           * probe position and velocity in GEI, GSE, and GSM coordinates;
           * flags to indicate regions of interest and maneuver status;
           * RA and declination of spin axis;
           * spin period and spin phase;
           * spin model parameters for high-precision interpolation of spin phase between one-minute data points.

           Version number indicates data source as follows:

           * V00: predicted ephemeris and attitude, no spin period or spin phase;
           * V01: predicted ephemeris and attitude, spin period and spin phase derived from probe telemetry;
           * V02: predicted attitude, definitive ephemeris from magnetometer and Doppler tracking data;
           * V03: corrected attitude and spin phase derived from fully calibrated magnetometer data. (added science attitude determination using perigee data post-processing).

           Produced by Mission Ops, Science Ops and Science Team.
Acknowledgement
NASA Contract NAS5-02099
Contacts
RolePersonStartDateStopDateNote
1.PrincipalInvestigatorspase://SMWG/Person/Vassilis.Angelopoulos
InformationURL
Name
THEMIS Data Overview
URL
Description

Overview of THEMIS data, descriptions, and data policy.

InformationURL
Name
THEMIS Data Policy and Credits
URL
Description

Details on THEMIS data policy and giving proper credits in publications.

InformationURL
Name
THEMIS Ephemeris Format Definition
URL
Description

Ephemeris file format and quantity details including RoI descriptions.

PriorIDs
spase://VMO/NumericalData/THEMIS/B/Ephemeris/PT01M
spase://VSPO/NumericalData/THEMIS/B/Ephemeris/PT01M
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
FTPS from SPDF (not with most browsers)
URL
Description

NASA/GSFC CDAWeb ftp access to the data.

AccessURL
Name
HTTPS from SPDF
URL
Description

In CDF via HTTP from SPDF

AccessURL
Name
CDAWeb
URL
ProductKey
THB_L1_STATE
Description

Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb

AccessURL
Format
CDF
Encoding
None
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
CDAWeb HAPI Server
URL
Style
HAPI
ProductKey
THB_L1_STATE@0
ProductKey
THB_L1_STATE@1
ProductKey
THB_L1_STATE@2
Description

Web Service to this product using the HAPI interface.

Format
CSV
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
THEMIS L1 state data at UC Berkeley
URL
Description

CDF data files for download, organized by date.

Format
CDF
Encoding
None
ProcessingLevel
Uncalibrated
ProviderProcessingLevel
Level 1
ProviderVersion
v3
InstrumentIDs
MeasurementType
Ephemeris
TemporalDescription
TimeSpan
StartDate
2007-02-17 23:35:58
RelativeStopDate
-P7D
Cadence
PT01M
ObservedRegion
Heliosphere.NearEarth
ObservedRegion
Earth.Magnetosphere.Magnetotail
ObservedRegion
Earth.Magnetosphere.Main
ObservedRegion
Earth.Magnetosheath
Caveats
Typical cadence is 1 min, occasionally 3s.
Parameter #1
Name
THEMIS-B Position (GEI)
ParameterKey
thb_pos
Description

THEMIS-B position vector (km) in GEI coordinates.

Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Structure
Size
3
Element
Name
X GEI
Qualifier
Component.I
Index
1
Element
Name
Y GEI
Qualifier
Component.J
Index
2
Element
Name
Z GEI
Qualifier
Component.K
Index
3
ValidMin
-1000000.0
ValidMax
1000000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #2
Name
THEMIS-B Velocity (GEI)
ParameterKey
thb_vel
Description

THEMIS-B velocity vector (km/s) in GEI coordinates.

Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Structure
Size
3
Element
Name
Vx GEI
Qualifier
Component.I
Index
1
Element
Name
Vy GEI
Qualifier
Component.J
Index
2
Element
Name
Vz GEI
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Velocity
Parameter #3
Name
THEMIS-B Maneuver Flag
ParameterKey
thb_man
Description

THEMIS-B maneuver status code (XYYZZZ). Values indicate if/what maneuver is being performed. Spacecraft data will be unreliable during maneuvers.

  * Unpowered flight (Coast):
      - X=0, Y=00, Z=000            
  * Sequence Code X:
      - 0= No Segmentation
      - 1= Segmented Maneuver
  * Type Code YY:
      - 0= No Maneuver
      - 1= Axial-thrust Maneuver
      - 2= Side-thrust Maneuver
      - 3= Beta-thrust Maneuver
      - 4= Attitude Precession
      - 5= Spin-Rate Change
  * Sequence Number ZZZ:
      - 001-999= Maneuver Sequence Number
ValidMin
0
ValidMax
4294967295
FillValue
4294967295
Support
SupportQuantity
Other
Parameter #4
Name
THEMIS-B RoI
ParameterKey
thb_roi
Description

Region of interest. Different bits of this parameter give a general indication of the region thbt the spacecraft is in. The first 18 bits are significant. An active bit indicates the spacecraft is in a given region. Multiple bits may be set simultaneously. The value of the bit is in parentheses in the following table.

      +---------------------------------------------------+
      | Bit 1(1)      | Earth Shadow                      |
      | Bit 2(2)      | Lunar Shadow                      |
      | Bit 3(4)      | Atmospheric absorbtion zone       |
      | Bit 4(8)      | South Atlantic Anomaly            |
      | Bit 5(16)     | Northern Auroral Zone             |
      | Bit 6(32)     | Southern Auroral Zone             |
      | Bit 7(64)     | Perigee Passage                   |
      | Bit 8(128)    | Inner & Outer Radiation Belts |
      | Bit 9(256)    | Deep Plasma Sphere                |
      | Bit 10(512)   | Foreshock Solar Wind              |
      | Bit 11(1024)  | Solar Wind Beam                   |
      | Bit 12(2048)  | High Magnetic Field               |
      | Bit 13(4096)  | Average Plasma Sheet              |
      | Bit 14(8192)  | Bowshock Crossing                 |
      | Bit 15(16384) | Magnetopause Crossing             |
      | Bit 16(32768) | Ground Based Observatories        |
      | Bit 17(65536) | 2-Day Conjunctions                |
      | Bit 18(131072)| 4-Day Conjunctions                |
      +---------------------------------------------------+
ValidMin
0
ValidMax
4294967295
FillValue
4294967295
Support
SupportQuantity
Other
Parameter #5
Name
THEMIS-B Spin Right Ascension
ParameterKey
thb_spinras
Description

THEMIS-B spin axis right ascension in GEI coordinates.

Caveats
Measured from GEI x-axis towards GEI y-axis.
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEI
ValidMin
0.0
ValidMax
360.0
FillValue
NaN
Support
Qualifier
DirectionAngle.AzimuthAngle
SupportQuantity
Positional
Parameter #6
Name
THEMIS-B Spin Declination
ParameterKey
thb_spindec
Description

THEMIS-B spin axis declination in GEI coordinates.

Caveats
Measured from GEI x-y axis towards GEI z-axis.
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEI
ValidMin
-90.0
ValidMax
90.0
FillValue
NaN
Support
Qualifier
DirectionAngle.ElevationAngle
SupportQuantity
Positional
Parameter #7
Name
THEMIS-B Spin Alpha
ParameterKey
thb_spinalpha
Description

THEMIS-B spin axis azimuth, Euler alpha, in Probe Geometric (SPG) coordinates

Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
ValidMin
0.0
ValidMax
360.0
FillValue
NaN
Support
Qualifier
DirectionAngle.AzimuthAngle
SupportQuantity
Positional
Parameter #8
Name
THEMIS-B Spin Beta
ParameterKey
thb_spinbeta
Description

THEMIS-B spin axis colatitude, Euler beta, in Probe Geometric (SPG) coordinates

Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
ValidMin
0.0
ValidMax
180.0
FillValue
NaN
Support
Qualifier
DirectionAngle.PolarAngle
SupportQuantity
Positional
Parameter #9
Name
THEMIS-B Spin Period
ParameterKey
thb_spinper
Description

THEMIS-B spin period, regularized and boxcar averaged.

Units
s
ValidMin
0.0
ValidMax
30.0
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #10
Name
THEMIS-B Spin PhaseAngle
ParameterKey
thb_spinphase
Description

THEMIS-B angle rotated since the sun sensor registered the sun pulse, regularized and boxcar averaged.

Units
deg
ValidMin
0.0
ValidMax
360.0
FillValue
NaN
Support
Qualifier
PhaseAngle
SupportQuantity
Positional
Parameter #11
Name
THEMIS-B Time
ParameterKey
thb_state_time
Description

Time, UTC, in seconds since 01-Jan-1970 00:00:00.

Caveats
Not including leap seconds.
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #12
Name
Spin Correction Time
ParameterKey
thb_spin_correction_time
Description

Spin correction time, UTC, in seconds since 01-Jan-1970 00:00:00

Caveats
Unleaped seconds
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #13
Name
THEMIS-B Initial Spin Period
ParameterKey
thb_spin_spinper
Description

Initial spin period for segment.

Units
s
ValidMin
0.0
ValidMax
30.0
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #14
Name
THEMIS-B Spin Time
ParameterKey
thb_spin_time
Description

Spin time, UTC, in seconds since 01-Jan-1970 00:00:00.

Caveats
Not including leap seconds.
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #15
Name
THEMIS-B Spin End Time
ParameterKey
thb_spin_tend
Description

Segment end time, UTC, in seconds since 01-Jan-1970 00:00:00

Caveats
Not including leap seconds
Units
s
ValidMin
0.0
ValidMax
5.0E9
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #16
Name
THEMIS-B Drift Term ('c')
ParameterKey
thb_spin_c
Description

Drift term for spin rate

Caveats
Applies to angular velocity (deg/sec), not spin period.
Units
deg/s^2
ValidMin
-30.0
ValidMax
30.0
FillValue
NaN
Support
SupportQuantity
Other
Parameter #17
Name
THEMIS-B Spin Correction
ParameterKey
thb_spin_correction
Description

Spin phase correction from definitive position and field model calculated at 1 minute intervals

Units
deg
ValidMin
-180.0
ValidMax
180.0
FillValue
NaN
Support
Qualifier
DirectionAngle
SupportQuantity
Other
Parameter #18
Name
Spin Axis Right Ascension Correction
ParameterKey
thb_spinras_correction
Description

Spin axis right ascension correction from definitive position and field model

Units
deg
ValidMin
-180
ValidMax
180
FillValue
NaN
Support
SupportQuantity
Other
Parameter #19
Name
Spin Axis Declination Correction
ParameterKey
thb_spindec_correction
Description

Spin axis declination correction from definitive position and field model

Units
deg
ValidMin
-180
ValidMax
180
FillValue
NaN
Support
SupportQuantity
Other
Parameter #20
Name
THEMIS-B Phase Error
ParameterKey
thb_spin_phaserr
Description

Maximum absolute phase error between model and non-outlier sun crossing time.

Caveats
Errors due to recognized BAU timing errors do not contribute to this quantity.
Units
s
ValidMin
0.0
ValidMax
30.0
FillValue
NaN
Support
Qualifier
Uncertainty
SupportQuantity
Temporal
Parameter #21
Name
THEMIS-B Spin Number
ParameterKey
thb_spin_nspins
Description

Number of spins contained in this segment.

ValidMin
0
ValidMax
65535
FillValue
65535
Support
SupportQuantity
Other
Parameter #22
Name
THEMIS-B Sample Number
ParameterKey
thb_spin_npts
Description

Number of samples (points) contained in this segment.

ValidMin
0
ValidMax
65535
FillValue
65535
Support
SupportQuantity
Other
Parameter #23
Name
THEMIS-B Pulse Gap
ParameterKey
thb_spin_maxgap
Description

Duration, in seconds, of longest gap between sun pulses in this segment. Long gaps (60 sec or more) will generally indicate shadow periods.

Units
s
ValidMin
0.0
ValidMax
86400.0
FillValue
NaN
Support
SupportQuantity
Temporal
Parameter #24
Name
THEMIS-B Position (GSE)
ParameterKey
thb_pos_gse
Description

Spacecraft position vector (km) in GSE coordinates.

Cadence
PT01M
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Element
Name
X GSE
Qualifier
Component.I
Index
1
Element
Name
Y GSE
Qualifier
Component.J
Index
2
Element
Name
Z GSE
Qualifier
Component.K
Index
3
ValidMin
-1000000.0
ValidMax
1000000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #25
Name
THEMIS-B Position (GSM)
ParameterKey
thb_pos_gsm
Description

Spacecraft position vector (km) in GSM coordinates.

Cadence
PT01M
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Element
Name
X GSM
Qualifier
Component.I
Index
1
Element
Name
Y GSM
Qualifier
Component.J
Index
2
Element
Name
Z GSM
Qualifier
Component.K
Index
3
ValidMin
-1000000.0
ValidMax
1000000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #26
Name
THEMIS-B Velocity (GSE)
ParameterKey
thb_vel_gse
Description

Spacecraft velocity (km/s) in GSE coordinates.

Cadence
PT01M
Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Element
Name
Vx GSE
Qualifier
Component.I
Index
1
Element
Name
Vy GSE
Qualifier
Component.J
Index
2
Element
Name
Vz GSE
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Velocity
Parameter #27
Name
THEMIS-B Velocity (GSM)
ParameterKey
thb_vel_gsm
Description

Spacecraft velocity (km/s) in GSM coordinates.

Cadence
PT01M
Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Element
Name
Vx GSM
Qualifier
Component.I
Index
1
Element
Name
Vy GSM
Qualifier
Component.J
Index
2
Element
Name
Vz GSM
Qualifier
Component.K
Index
3
ValidMin
-1000.0
ValidMax
1000.0
FillValue
NaN
Support
Qualifier
Vector
SupportQuantity
Velocity