scholarly journals How many solar wind data are sufficient for accurate fluxgate magnetometer offset determinations?

2019 ◽  
Vol 8 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Ferdinand Plaschke
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Wind Data ◽  
Fluxgate Magnetometer ◽  
Time Intervals ◽  
Sensor Position ◽  
Magnetic Field Measurements ◽  
Wind Measurements ◽  
The Magnetic Field

Abstract. Accurate magnetic field measurements by fluxgate magnetometers onboard spacecraft require ground and regular in-flight calibration activities. Therewith, the parameters of a coupling matrix and an offset vector are adjusted; they are needed to transform raw magnetometer outputs into calibrated magnetic field measurements. The components of the offset vector are typically determined by analyzing Alfvénic fluctuations in the solar wind if solar wind measurements are available. These are characterized by changes in the field components, while the magnetic field modulus stays constant. In this paper, the following question is answered: how many solar wind data are sufficient for accurate fluxgate magnetometer offset determinations? It is found that approximately 40 h of solar wind data are sufficient to achieve offset accuracies of 0.2 nT, and about 20 h suffice for accuracies of 0.3 nT or better if the magnetometer offsets do not drift within these time intervals and if the spacecraft fields do not vary at the sensor position. Offset determinations with uncertainties lower than 0.1 nT, however, would require at least hundreds of hours of solar wind data.

scholarly journals How much solar wind data are sufficient for accurate fluxgate magnetometer offset determinations?

2019 ◽  
Author(s):  
Ferdinand Plaschke
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Wind Data ◽  
Fluxgate Magnetometer ◽  
Time Intervals ◽  
Sensor Position ◽  
Magnetic Field Measurements ◽  
Wind Measurements ◽  
The Magnetic Field

Abstract. Accurate magnetic field measurements by fluxgate magnetometers on-board spacecraft require ground and regular in-flight calibrations activities. Therewith, the parameters of a coupling matrix and an offset vector are adjusted; they are needed to transform raw magnetometer outputs into calibrated magnetic field measurements. The components of the offset vector are typically determined by analyzing Alfvénic fluctuations in the solar wind, if solar wind measurements are available. These are characterized by changes in the field components, while the magnetic field modulus stays constant. In this paper, the following question is answered: How much solar wind data are sufficient for accurate fluxgate magnetometer offset determinations? It is found that approximately 50 hours of solar wind data are sufficient to achieve offset accuracies of 0.2 nT, and about 20 hours suffice for accuracies of 0.3 nT or better, if the magnetometer offsets do not drift within these time intervals and if the spacecraft fields do not vary at the sensor position. Offset determinations with uncertainties lower than 0.1 nT, however, would require at least hundreds of hours of solar wind data.

scholarly journals Error estimate for fluxgate magnetometer in-flight calibration on a spinning spacecraft

2021 ◽  
Vol 10 (1) ◽  
pp. 13-24
Author(s):  
Yasuhito Narita ◽  
Ferdinand Plaschke ◽  
Werner Magnes ◽  
David Fischer ◽  
Daniel Schmid
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Experimental Studies ◽  
Field Measurements ◽  
Fluxgate Magnetometer ◽  
Uncertainty Sources ◽  
Field Environment ◽  
Magnetic Field Measurements ◽  
Error Formulas ◽  
The Magnetic Field

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.

scholarly journals Scattering of field-aligned beam ions upstream of Earth's bow shock

2007 ◽  
Vol 25 (3) ◽  
pp. 785-799 ◽  
Author(s):  
A. Kis ◽  
M. Scholer ◽  
B. Klecker ◽  
H. Kucharek ◽  
E. A. Lucek ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Bow Shock ◽  
Ion Distribution ◽  
Parallel Side ◽  
Earth’S Bow Shock ◽  
High Mach ◽  
The Magnetic Field

Abstract. Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB) ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

scholarly journals The fluxgate magnetometer of the Low Orbit Pearl Satellites (LOPS): overview of in-flight performance and initial results

2021 ◽  
Vol 10 (2) ◽  
pp. 227-243
Author(s):  
Ye Zhu ◽  
Aimin Du ◽  
Hao Luo ◽  
Donghai Qiao ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Current System ◽  
Field Measurements ◽  
Stray Field ◽  
Fluxgate Magnetometer ◽  
General Description ◽  
Flight Performance ◽  
Spatial Coverage ◽  
Magnetic Field Measurements ◽  
Initial Results

Abstract. The Low Orbit Pearl Satellite series consists of six constellations, with each constellation consisting of three identical microsatellites that line up just like a string of pearls. The first constellation of three satellites were launched on 29 September 2017, with an inclination of ∼ 35.5∘ and ∼ 600 km altitude. Each satellite is equipped with three identical fluxgate magnetometers that measure the in situ magnetic field and its low-frequency fluctuations in the Earth's low-altitude orbit. The triple sensor configuration enables separation of stray field effects generated by the spacecraft from the ambient magnetic field (e.g., Zhang et al., 2006). This paper gives a general description of the magnetometer including the instrument design, calibration before launch, in-flight calibration, in-flight performance, and initial results. Unprecedented spatial coverage resolution of the magnetic field measurements allow for the investigation of the dynamic processes and electric currents of the ionosphere and magnetosphere, especially for the ring current and equatorial electrojet during both quiet geomagnetic conditions and storms. Magnetic field measurements from LOPS could be important for studying the method to separate their contributions of the Magnetosphere-Ionosphere (M-I) current system.

scholarly journals Development of Space Magnetometers in Austria

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1104
Author(s):  
Werner Magnes ◽  
Roland Lammegger ◽  
Martin Agú ◽  
Christoph Amtmann ◽  
Özer Aydogar ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Field Measurements ◽  
Fundamental Information ◽  
Magnetic Field Measurements ◽  
The Magnetic Field

With spaceborne magnetic field measurements it is possible to investigate the interior of planets,moons and asteroids which have either an intrinsic or a crustal magnetic field. Furthermore, preciseknowledge of the magnetic field is essential to derive fundamental information about theenvironment surrounding different bodies in the solar system as well as to explore the interplanetaryspace. [...]

Solar Wind Measurements from the Planetary Magnetometer Onboard the BepiColombo Spacecraft

2020 ◽  
Author(s):  
Daniel Heyner ◽  
Ingo Richter ◽  
Ferdinand Plaschke ◽  
David Fischer ◽  
Johannes Mieth ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Electric Propulsion ◽  
Small Scale ◽  
Solar Electric Propulsion ◽  
Scientific Analysis ◽  
Wind Measurements ◽  
Propulsion Phase ◽  
The Magnetic Field ◽  
Magnetic Disturbances

<p>BepiColombo is en-route to Mercury. The boom carrying the planetary magnetometers (MPO-MAG instrument) was deployed in space on 25th of October in 2018. After the deployment, the magnetic disturbances arising from the spacecraft have been greatly decreased. Since the deployment, the fluxgate sensors have been monitoring the magnetic field continuously except for the solar electric propulsion phase. Extensive calibration and data processing activities have since enabled us to greatly decrease spacecraft-generated <br>disturbances in the magnetic field observations; these activities constitute a key step towards making the data <br>suitable for scientific analysis. We present a few cases of identified magnetic disturbances, discuss the challenges <br>they pose, and compare methods to clean the data. We also compare MPO-MAG measurements to observations by the <br>Advanced Composition Explorer (ACE) solar wind monitor, thereby highlighting the small-scale nature and rapid <br>evolution of interplanetary magnetic field (IMF) variations. We conclude with an overview of the scientific <br>goals of the instrument team for the in-orbit mission phase.</p>

Simultaneous plasma and magnetic-field measurements of probable tangential discontinuities in the solar wind

Solar Physics ◽  
1969 ◽  
Vol 6 (3) ◽  
pp. 456-464 ◽  
Author(s):  
George L. Siscoe ◽  
James M. Turner ◽  
Alan J. Lazarus
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Magnetic Field Measurements ◽  
Tangential Discontinuities

scholarly journals Measurements of the magnetic field in WD 1658+441

2013 ◽  
Vol 9 (S302) ◽  
pp. 402-403
Author(s):  
J. Ramírez Vélez ◽  
D. Hiriart ◽  
G. Valyavin ◽  
J. Valdez ◽  
F. Quiroz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
White Dwarf ◽  
Longitudinal Magnetic Field ◽  
Field Measurements ◽  
Measured Variable ◽  
Preliminary Results ◽  
San Pedro ◽  
Magnetic Field Measurements ◽  
Object Of Study ◽  
The Magnetic Field

AbstractWe present the preliminary results of the measurements of longitudinal magnetic field of the massive white dwarf 1658+441. This star have an hydrogen pure atmosphere (e.g. Dupuis & Chayer, 2003). We have observed the target in a total of 18 hrs during 3 consecutive nights in June 2010 and one more in May 2011. The data was acquired with a prototypical spectropolarimeter at the San Pedro Martir Telescope in Mexico. We have tested the magnetic field measurements with our instrument using the famous Babcock's star obtaining consistent results with previous studies. For our object of study, the WD 1658+441, we have measured variable intensities of the longitudinal magnetic field of Blong = 720 kG that oscillates with an amplitude of 130 kG.

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