Version:2.4.0
NumericalData
ResourceID
spase://CNES/NumericalData/CDPP-Archive/THEMIS-D/DefinitiveEphemeris/THEMIS_AUX_THD_L1_EPHEM
ResourceHeader
ResourceName
THEMIS-D Definitive Ephemeris and Spin Attitude Corrections (CDF)
DOI
https://doi.org/10.24400/802406/s9ta-wryh
ReleaseDate
2022-01-21 08:24:17Z
Description
This dataset contains THEMIS-D position, velocity, attitude and sun pulse data.
The data are definitive with added science attitude determination using perigee data post-processing.
Contacts
AccessInformation
RepositoryID
Availability
Online
AccessURL
Name
REGARDS
URL
Description
Access via CNES Data Archive for CDPP
Format
CDF
ProcessingLevel
Uncalibrated
InstrumentIDs
MeasurementType
Ephemeris
TemporalDescription
TimeSpan
StartDate
2007-02-28 00:00:00Z
StopDate
2013-02-20 00:00:00Z
ObservedRegion
Heliosphere.NearEarth
ObservedRegion
Earth.Magnetosphere.Magnetotail
ObservedRegion
Earth.Magnetosphere.Main
ObservedRegion
Earth.Magnetosheath
Parameter #1
Name
THEMIS-D position vector in GEI coordinates
Description
THEMIS-D position vector (km) in GEI coordinates
Units
km
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #2
Name
THEMIS-D velocity vector in GEI coordinates
Description
THEMIS-D velocity vector (km/s) in GEI coordinates
Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GEI
Support
Qualifier
Vector
SupportQuantity
Velocity
Parameter #3
Name
THEMIS-D Maneuver Flag
Description
THEMIS-D 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
Support
Parameter #4
Name
THEMIS-D RoI
Description
Region of interest. Different bits of this parameter give a general indication of the region that 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 |
+---------------------------------------------------+
Support
Parameter #5
Name
THEMIS-D spin axis right ascension
Description
THEMIS-D spin axis right ascension in GEI coordinates.
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEI
Support
Qualifier
DirectionAngle.AzimuthAngle
SupportQuantity
Positional
Parameter #6
Name
THEMIS-D spin axis declination in GEI coordinates
Description
THEMIS-D spin axis declination in GEI coordinates
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
GEI
Support
Qualifier
DirectionAngle.ElevationAngle
SupportQuantity
Positional
Parameter #7
Name
THEMIS-D spin axis azimuth, Euler alpha, in Probe Geometric (SPG) coordinates
Description
THEMIS-D spin axis azimuth, Euler alpha, in Probe Geometric (SPG) coordinates
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
Support
Qualifier
DirectionAngle.AzimuthAngle
SupportQuantity
Positional
Parameter #8
Name
THEMIS-D spin axis colatitude, Euler beta, in Probe Geometric (SPG) coordinates
Description
THEMIS-D spin axis colatitude, Euler beta, in Probe Geometric (SPG) coordinates
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
SC
Support
Qualifier
DirectionAngle.PolarAngle
SupportQuantity
Positional
Parameter #9
Name
THEMIS-D spin period, regularized and boxcar averaged
Description
THEMIS-D spin period, regularized and boxcar averaged
Units
s
Support
Parameter #10
Name
THEMIS-D angle rotated since the sun sensor registered the sun pulse, regularized and boxcar averaged.
Description
THEMIS-D angle rotated since the sun sensor registered the sun pulse, regularized and boxcar averaged.
Units
deg
Support
Qualifier
PhaseAngle
SupportQuantity
Positional
Parameter #11
Name
THEMIS-D Initial Spin Period for segment
Description
THEMIS-D Initial Spin Period for segment
Units
s
Support
Parameter #12
Name
THEMIS-D Drift term for spin rate
Description
Drift term for spin rate
Caveats
Applies to angular velocity (deg/sec), not spin period.
Units
deg/s^2
Support
Parameter #13
Name
THEMIS-D Spin Correction
Description
THEMIS-D Spin phase correction from definitive position and field model calculated at 1 minute intervals
Units
deg
Support
Qualifier
DirectionAngle
SupportQuantity
Other
Parameter #14
Name
THEMIS-D Spin axis right ascension
Description
Spin axis right ascension correction from definitive position and field model
Units
deg
Support
Parameter #15
Name
THEMIS-D Spin axis declination
Description
Spin axis declination correction from definitive position and field model
Units
deg
Support
Parameter #16
Name
THEMIS-D Maximum absolute phase error
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
Support
Qualifier
Uncertainty
SupportQuantity
Temporal
Parameter #17
Name
THEMIS-D Number of spins contained in this segment
Description
THEMIS-D Number of spins contained in this segment
Support
Parameter #18
Name
THEMIS-D Pulse Gap
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
Support
Parameter #19
Name
THEMIS-D Position (GSE)
Description
Spacecraft position vector (km) in GSE coordinates
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #20
Name
THEMIS-D Position (GSM)
Description
Spacecraft position vector (km) in GSM coordinates
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Support
Qualifier
Vector
SupportQuantity
Positional
Parameter #21
Name
THEMIS-D Velocity (GSE)
Description
Spacecraft velocity (km/s) in GSE coordinates
Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Support
Qualifier
Vector
SupportQuantity
Velocity
Parameter #22
Name
THEMIS-D Velocity (GSM)
Description
Spacecraft velocity (km/s) in GSM coordinates
Units
km/s
UnitsConversion
1e3>m/s
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Support
Qualifier
Vector
SupportQuantity
Velocity