2.7.1
https://spdx.org/licenses/
SPDX
CC0-1.0
https://spdx.org/licenses/CC0-1.0.html
Creative Commons Zero v1.0 Universal
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions
spase://NASA/NumericalData/THEMIS/C/Ephemeris/PT01M
NASA
NumericalData
THEMIS-C Level 1 Probe State Data
https://doi.org/10.48322/8c98-ds28
2025-12-04T13:31:43Z
2021-04-27T15:38:11
Only known prior ReleaseDate of the metadata
2025-10-21T12:34:56.789
Revised ObservedRegion. JMW
2025-11-14T16:02:56Z
Added PublicationInfo. 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
2025-12-04T13:31:43Z
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
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.
NASA Contract NAS5-02099
Angelopoulos, Vassilis
2025-11-14T16:02:56Z
Space Physics Data Facility
spase://SMWG/Person/Vassilis.Angelopoulos
PrincipalInvestigator
THEMIS Data Overview
http://themis.ssl.berkeley.edu/overview_data.shtml
Overview of THEMIS data, descriptions, and data policy.
THEMIS Data Policy and Credits
http://themis.ssl.berkeley.edu/roadrules.shtml
Details on THEMIS data policy and giving proper credits in publications.
THEMIS Ephemeris Format Definition
https://spdf.gsfc.nasa.gov/pub/data/themis/documents/tdas/docs/thm_ogs_431m_ephemeris_format_definition.pdf
Ephemeris file format and quantity details including RoI descriptions.
spase://VMO/NumericalData/THEMIS/C/Ephemeris/PT01M
spase://VSPO/NumericalData/THEMIS/C/Ephemeris/PT01M
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Online
Open
https://spdx.org/licenses/
SPDX
CC0-1.0
https://spdx.org/licenses/CC0-1.0.html
Creative Commons Zero v1.0 Universal
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
FTPS from SPDF (not with most browsers)
ftps://spdf.gsfc.nasa.gov/pub/data/themis/thc/l1/state/
NASA/GSFC CDAWeb ftp access to the data.
HTTPS from SPDF
https://spdf.gsfc.nasa.gov/pub/data/themis/thc/l1/state/
In CDF via HTTP from SPDF
CDF
None
spase://SMWG/Repository/UCB/THEMIS
Online
Open
CDAWeb
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=THC_L1_STATE&index=sp_phys
THC_L1_STATE
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
SSCWeb
https://sscweb.gsfc.nasa.gov/cgi-bin/Locator.cgi
themisc
THEMIS L1 state data at UC Berkeley
http://themis.ssl.berkeley.edu/data/themis/thc/l1/state/
CDF data files for download, organized by date.
CDF
None
https://cdaweb.gsfc.nasa.gov/pub/data/themis/thc/l1/state/$Y
thc_l1_state_$Y$m$d_$v.cdf
spase://SMWG/Repository/NASA/GSFC/SPDF
Online
Open
CDAWeb Programmatic Data Access
https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/THC_L1_STATE/clientLibraryExample/
THC_L1_STATE
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Binary
spase://SMWG/Repository/NASA/GSFC/SPDF
Online
Open
SSCWeb Programmatic Data Access
https://sscweb.gsfc.nasa.gov/WS/sscr/2/observatories/THC_L1_STATE/clientLibraryExample/
THC_L1_STATE
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Binary
spase://SMWG/Repository/NASA/GSFC/SPDF
Online
Open
4D Orbit Viewer
https://sscweb.gsfc.nasa.gov/4dorbit/?sc=THC_L1_STATE
THC_L1_STATE
4D viewer for this data. Note: this AccessInformation element was added by HDPWS.
HTML
spase://SMWG/Repository/NASA/GSFC/SPDF
Online
Open
https://spdx.org/licenses/
SPDX
CC0-1.0
https://spdx.org/licenses/CC0-1.0.html
Creative Commons Zero v1.0 Universal
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
CDAWeb HAPI Server
https://cdaweb.gsfc.nasa.gov/hapi
THC_L1_STATE@0
THC_L1_STATE@1
THC_L1_STATE@2
Web Service to this product using the HAPI interface.
CSV
Uncalibrated
Level 1
v3
spase://SMWG/Instrument/THEMIS/C/Ephemeris
Ephemeris
2007-02-17T23:35:58
-P7D
PT01M
Heliosphere.NearEarth
Earth.Magnetosphere.Magnetotail
Earth.Magnetosphere.Main
Earth.Magnetosheath
Earth.Magnetosphere
Earth.Magnetosphere.RadiationBelt
Typical cadence is 1 min, occasionally 3s.
THEMIS-C Position (GEI)
thc_pos
THEMIS-C position vector (km) in GEI coordinates.
km
1e3>m
Cartesian
GEI
3
X GEI
Component.I
1
Y GEI
Component.J
2
Z GEI
Component.K
3
-1000000.0
1000000.0
NaN
Vector
Positional
THEMIS-C Velocity (GEI)
thc_vel
THEMIS-C velocity vector (km/s) in GEI coordinates.
km/s
1e3>m/s
Cartesian
GEI
3
Vx GEI
Component.I
1
Vy GEI
Component.J
2
Vz GEI
Component.K
3
-1000.0
1000.0
NaN
Vector
Velocity
THEMIS-C Maneuver Flag
thc_man
THEMIS-C 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
0
4294967295
4294967295
Other
THEMIS-C RoI
thc_roi
Region of interest. Different bits of this parameter give a general indication of the region thct 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 |
+---------------------------------------------------+
0
4294967295
4294967295
Other
THEMIS-C Spin Right Ascension
thc_spinras
THEMIS-C spin axis right ascension in GEI coordinates.
Measured from GEI x-axis towards GEI y-axis.
deg
Spherical
GEI
0.0
360.0
NaN
DirectionAngle.AzimuthAngle
Positional
THEMIS-C Spin Declination
thc_spindec
THEMIS-C spin axis declination in GEI coordinates.
Measured from GEI x-y axis towards GEI z-axis.
deg
Spherical
GEI
-90.0
90.0
NaN
DirectionAngle.ElevationAngle
Positional
THEMIS-C Spin Alpha
thc_spinalpha
THEMIS-C spin axis azimuth, Euler alpha, in Probe Geometric (SPG) coordinates
deg
Spherical
SC
0.0
360.0
NaN
DirectionAngle.AzimuthAngle
Positional
THEMIS-C Spin Beta
thc_spinbeta
THEMIS-C spin axis colatitude, Euler beta, in Probe Geometric (SPG) coordinates
deg
Spherical
SC
0.0
180.0
NaN
DirectionAngle.PolarAngle
Positional
THEMIS-C Spin Period
thc_spinper
THEMIS-C spin period, regularized and boxcar averaged.
s
0.0
30.0
NaN
Temporal
THEMIS-C Spin PhaseAngle
thc_spinphase
THEMIS-C angle rotated since the sun sensor registered the sun pulse, regularized and boxcar averaged.
deg
0.0
360.0
NaN
PhaseAngle
Positional
THEMIS-C Time
thc_state_time
Time, UTC, in seconds since 01-Jan-1970 00:00:00.
Not including leap seconds.
s
0.0
5.0E9
NaN
Temporal
Spin Correction Time
thc_spin_correction_time
Spin correction time, UTC, in seconds since 01-Jan-1970 00:00:00
Unleaped seconds
s
0.0
5.0E9
NaN
Temporal
THEMIS-C Initial Spin Period
thc_spin_spinper
Initial spin period for segment.
s
0.0
30.0
NaN
Temporal
THEMIS-C Spin Time
thc_spin_time
Spin time, UTC, in seconds since 01-Jan-1970 00:00:00.
Not including leap seconds.
s
0.0
5.0E9
NaN
Temporal
THEMIS-C Spin End Time
thc_spin_tend
Segment end time, UTC, in seconds since 01-Jan-1970 00:00:00
Not including leap seconds
s
0.0
5.0E9
NaN
Temporal
THEMIS-C Drift Term ('c')
thc_spin_c
Drift term for spin rate
Applies to angular velocity (deg/sec), not spin period.
deg/s^2
-30.0
30.0
NaN
Other
THEMIS-C Spin Correction
thc_spin_correction
Spin phase correction from definitive position and field model calculated at 1 minute intervals
deg
-180.0
180.0
NaN
DirectionAngle
Other
Spin Axis Right Ascension Correction
thc_spinras_correction
Spin axis right ascension correction from definitive position and field model
deg
-180
180
NaN
Other
Spin Axis Declination Correction
thc_spindec_correction
Spin axis declination correction from definitive position and field model
deg
-180
180
NaN
Other
THEMIS-C Phase Error
thc_spin_phaserr
Maximum absolute phase error between model and non-outlier sun crossing time.
Errors due to recognized BAU timing errors do not contribute to this quantity.
s
0.0
30.0
NaN
Uncertainty
Temporal
THEMIS-C Spin Number
thc_spin_nspins
Number of spins contained in this segment.
0
65535
65535
Other
THEMIS-C Sample Number
thc_spin_npts
Number of samples (points) contained in this segment.
0
65535
65535
Other
THEMIS-C Pulse Gap
thc_spin_maxgap
Duration, in seconds, of longest gap between sun pulses in this segment. Long gaps (60 sec or more) will generally indicate shadow periods.
s
0.0
86400.0
NaN
Temporal
THEMIS-C Position (GSE)
thc_pos_gse
Spacecraft position vector (km) in GSE coordinates.
PT01M
km
1e3>m
Cartesian
GSE
3
X GSE
Component.I
1
Y GSE
Component.J
2
Z GSE
Component.K
3
-1000000.0
1000000.0
NaN
Vector
Positional
THEMIS-C Position (GSM)
thc_pos_gsm
Spacecraft position vector (km) in GSM coordinates.
PT01M
km
1e3>m
Cartesian
GSM
3
X GSM
Component.I
1
Y GSM
Component.J
2
Z GSM
Component.K
3
-1000000.0
1000000.0
NaN
Vector
Positional
THEMIS-C Velocity (GSE)
thc_vel_gse
Spacecraft velocity (km/s) in GSE coordinates.
PT01M
km/s
1e3>m/s
Cartesian
GSE
3
Vx GSE
Component.I
1
Vy GSE
Component.J
2
Vz GSE
Component.K
3
-1000.0
1000.0
NaN
Vector
Velocity
THEMIS-C Velocity (GSM)
thc_vel_gsm
Spacecraft velocity (km/s) in GSM coordinates.
PT01M
km/s
1e3>m/s
Cartesian
GSM
3
Vx GSM
Component.I
1
Vy GSM
Component.J
2
Vz GSM
Component.K
3
-1000.0
1000.0
NaN
Vector
Velocity