### MFE Key Parameters

The MFE Key Parameters are generated at the CDHF from the 9.2 s
average despun vector data in the spacecraft level zero telemetry
stream. They are calculated at .92 minute resolution.

### Key Parameter Descriptions

**Epoch-time** is the standard CDHF time
**Position-GSE** is the spacecraft position in GSE
coordinates (x toward the Sun, y in the ecliptic plane in the direction
of Earth's orbital motion, z perpendicular to the ecliptic plane)
in Earth radii
**Position-GSM** is the spacecraft position in GSM
coordinates (x toward the Sun, z parallel to Earth's dipole axis, y
completing the right-handed system) in Earth radii
**Radial Distance** is the spacecraft radial distance from
the center of the Earth in Re
**Magnetic Field Strength** is the measured field
magnitude at the spacecraft, obtained from the sums of the squares
of the 9.2 s despun level zero data
**Vector Magnetic Field** is the measured field
vector (components) in spacecraft coordinates (x in the spin plane
along the projection of the solar direction, z along the spacecraft
spin axis, y completing the right-handed system), obtained by averaging
the despun 9.2 s level zero data
**Transverse Standard Deviation** is the transverse
standard deviation of the field calculated from the 9.2 s despun level
zero components with respect to the .92 min key parameter component
data
**Compressional Standard Deviation** is computed in
the same manner as the Transverse standard deviation, but using the
9.2 s and .92 min field magnitude averages
**Vector Field-GSE** is the field vector tansformed
to GSE coodinates
**Vector Field-GSM** is the field vector transformed
to GSM coordinates
**Model Field Strength** is the magnetic field magnitude
at the spacecraft position computed from the Tsyganenko 1989 empirical
magnetosphere field model *(N.A. Tsyganenko, A magnetosphere model with a
warped tail current sheet, Planet. Space Sci. 37, 5, 1989)* for the
prevailing dipole tilt at the time of the observation
**Model Vector Field-GSE** is the vector field in the
Tsyganenko model in GSE coordinates
**Model Vector Field-GSM** is the vector field in the
Tsyganenko model in GSM coordinates
**Model Difference Field-GSE**
**Model Difference Field-GSM**
**All Model Parameters for IGRF-90**
**model-aligned fields**
**data quality factor** is the number of 9.2 s
values contributing to each .92 min period used for key Parameter
calculation

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