Description:
<jats:p>Abstract. Fluxgate magnetometers are widely used
for in situ magnetic field measurements in the context of
geophysical and solar system studies.
Like in most experimental studies, magnetic field measurements
using the fluxgate magnetometers are constrained
by the associated uncertainties.
To evaluate the performance of magnetometers,
the measurement uncertainties of
calibrated magnetic field data are quantitatively
studied for a spinning spacecraft.
The uncertainties are derived analytically by
perturbing the calibration parameters
and are simplified into the first-order expression
including the offset errors and the coupling of
calibration parameter errors with the ambient magnetic field.
The error study shows how the uncertainty sources
combine through the calibration process.
The final error depends
on (1) the magnitude of the magnetic field
with respect to the offset error and
(2) the angle of the magnetic field to the spacecraft spin axis.
The offset uncertainties are the major factor
in a low-field environment, while the angle uncertainties
(rotation angle in the spin plane, sensor non-orthogonality,
and sensor misalignment to the spacecraft reference directions)
become more important in a high-field environment
in a proportional way to the magnetic field.
The error formulas serve as a useful tool
in designing high-precision magnetometers
in future spacecraft missions
as well as in data analysis methods in geophysical
and solar system science.
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