scholarly journals A radiation hardened digital fluxgate magnetometer for space applications

2013 ◽  
Vol 2 (2) ◽  
pp. 213-224 ◽  
Author(s):  
D. M. Miles ◽  
J. R. Bennest ◽  
I. R. Mann ◽  
D. K. Millling
Keyword(s):  
Magnetic Field ◽  
Temperature Compensation ◽  
Low Frequency ◽  
Radiation Belts ◽  
Fluxgate Magnetometer ◽  
Science Data ◽  
Space Applications ◽  
Outer Radiation Belt ◽  
Background Magnetic Field ◽  
New Instrument

Abstract. Space-based measurements of Earth's magnetic field are required to understand the plasma processes responsible for energising particles in the Van Allen radiation belts and influencing space weather. This paper describes a prototype fluxgate magnetometer instrument developed for the proposed Canadian Space Agency's (CSA) Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission and which has applications in other space and suborbital applications. The magnetometer is designed to survive and operate in the harsh environment of Earth's radiation belts and measure low-frequency magnetic waves, the magnetic signatures of current systems, and the static background magnetic field. The new instrument offers improved science data compared to its predecessors through two key design changes: direct digitisation of the sensor and digital feedback from two cascaded pulse-width modulators combined with analog temperature compensation. These provide an increase in measurement bandwidth up to 450 Hz with the potential to extend to at least 1500 Hz. The instrument can resolve 8 pT on a 65 000 nT field with a magnetic noise of less than 10 pT/√Hz at 1 Hz. This performance is comparable with other recent digital fluxgates for space applications, most of which use some form of sigma-delta (ΣΔ) modulation for feedback and omit analog temperature compensation. The prototype instrument was successfully tested and calibrated at the Natural Resources Canada Geomagnetics Laboratory.

scholarly journals A radiation hardened digital fluxgate magnetometer for space applications

2013 ◽  
Vol 3 (1) ◽  
pp. 31-58
Author(s):  
D. M. Miles ◽  
J. R. Bennest ◽  
I. R. Mann ◽  
D. K. Millling
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Radiation Belts ◽  
Digital Design ◽  
Fluxgate Magnetometer ◽  
Science Data ◽  
Space Applications ◽  
Outer Radiation Belt ◽  
Background Magnetic Field ◽  
New Instrument

Abstract. Space-based measurements of the Earth's magnetic field are required to understand the plasma processes responsible for energizing particles in the Van Allen radiation belts and influencing space weather. This paper describes a prototype fluxgate magnetometer instrument developed for the proposed Canadian Space Agency (CSA) Outer Radiation Belt Injection, Transport, Acceleration and Loss Satellite (ORBITALS) mission and which has applications in other space and suborbital applications. The magnetometer is designed to survive and operate in the harsh environment of the Earth's radiation belts and measure low-frequency magnetic waves, the magnetic signatures of current systems, and the static background magnetic field. The new instrument offers improved science data compared to its predecessors through two key design changes: direct digitisation of the sensor and digital feedback combined with analog temperature compensation. These provide an increase in measurement bandwidth up to 450 Hz with the potential to extend to at least 1500 Hz. The instrument can resolve 8 pT on a 65 000 nT field with a magnetic noise of less than 10 pT per square–root Hz at 1 Hz. The prototype instrument was successfully tested and calibrated at the Natural Resources Canada Geomagnetics Laboratory showing that the mostly-digital design matches or exceeds its radiation-soft analog predecessor in sensitivity, noise, frequency range, and RMS accuracy.

scholarly journals Properties of the singing comet waves in the 67P/Churyumov-Gerasimenko plasma environment as observed by the Rosetta mission

2019 ◽  
Vol 630 ◽  
pp. A39 ◽  
Author(s):  
H. Breuillard ◽  
P. Henri ◽  
L. Bucciantini ◽  
M. Volwerk ◽  
T. Karlsson ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Compressional Waves ◽  
Weibel Instability ◽  
Plasma Environment ◽  
Background Magnetic Field ◽  
Rosetta Mission ◽  
Ion Waves ◽  
Plasma Coupling

Using in situ measurements from different instruments on board the Rosetta spacecraft, we investigate the properties of the newly discovered low-frequency oscillations, known as singing comet waves, that sometimes dominate the close plasma environment of comet 67P/Churyumov-Gerasimenko. These waves are thought to be generated by a modified ion-Weibel instability that grows due to a beam of water ions created by water molecules that outgass from the comet. We take advantage of a cometary outburst event that occurred on 2016 February 19 to probe this generation mechanism. We analyze the 3D magnetic field waveforms to infer the properties of the magnetic oscillations of the cometary ion waves. They are observed in the typical frequency range (~50 mHz) before the cometary outburst, but at ~20 mHz during the outburst. They are also observed to be elliptically right-hand polarized and to propagate rather closely (~0−50°) to the background magnetic field. We also construct a density dataset with a high enough time resolution that allows us to study the plasma contribution to the ion cometary waves. The correlation between plasma and magnetic field variations associated with the waves indicates that they are mostly in phase before and during the outburst, which means that they are compressional waves. We therefore show that the measurements from multiple instruments are consistent with the modified ion-Weibel instability as the source of the singing comet wave activity. We also argue that the observed frequency of the singing comet waves could be a way to indirectly probe the strength of neutral plasma coupling in the 67P environment.

scholarly journals One second vector and scalar magnetic measurements at low latitude observatory, CPL

2017 ◽  
Author(s):  
Phani Chandrasekhar Nelapatla ◽  
Sai Vijay Kumar Potharaju ◽  
Kusumita Arora ◽  
Chandra Shakhar Rao Kasuba ◽  
Leonid Rakhlin ◽  
...  
Keyword(s):  
Real Time ◽  
Magnetic Measurements ◽  
Low Frequency ◽  
Magnetic Data ◽  
Magnetic Observatory ◽  
Fluxgate Magnetometer ◽  
Main Concern ◽  
Low Latitude ◽  
Time Space ◽  
New Instrument

Abstract. There is increasing demand from the global geomagnetic community for the recording of 1 second vector and scalar magnetic datain lieu of the traditional of the 1 minute data, as the 1 second magnetic data would be more compatible with measurements made from low-earth orbiting satellites and the increased detectability threshold, would contribute to: (i) understanding the global scale ultra-low frequency (ULF) waves, sudden impulses and other processes in the ionosphere & magnetosphere: (ii) development of real-time space weather forecasts. The combination of ground and satellite data opens a new pathway in understanding many underlying physical processes in the lower-middle atmospheric dynamics, which has not been accurately understood so far. The International Real-time Magnetic ObservatoryNetwork (INTERMAGNET)observatories (IMO-s) have taken a lead in this direction and many IMO-s now produce both 1 minute and 1 second data. Being affordable, rugged, compact as well as having low power consumption, fluxgate magnetometers are the staple vector sensors of IMO-s.The increased order of noise in these sensors with increasing frequencies, is the main concern and work has been going on for the last decade towards development of suitable instruments (Courtillot and Chulliat, 2008; Korepanov et al. 2006, 2009; Pedersen and Merenyi, 2016 and references therein, Dobrodnyak, 2014; Logvinov, 2014) and techniques for the evaluation and elimination of noise from the data is also being pursued (Turbitt et al. 2013). At the new Magnetic Observatory of CSIR-NGRI in Choutuppal (CPL) campus, 1 second magnetic measurements commenced in the year 2016 using the newly developed Observatory grade 1 second fluxgate magnetometer, GEOMAG-02MO, from GEOMAGNET Ukraine and the Overhauser Proton Precession Magnetometer along with the data acquisition system, MAGREC-4B. The processes of commissioning of this setup in low-latitude conditions, with the aim to finally produce 1 second definitive data (the standards of which are still under discussion with INTERMAGNET) and the characteristics of the data from this new instrument are presented in this work.

scholarly journals Indoor Mapping of Magnetic Fields Using UAV Equipped with Fluxgate Magnetometer

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4191
Author(s):  
Pavol Lipovský ◽  
Katarína Draganová ◽  
Jozef Novotňák ◽  
Zoltán Szőke ◽  
Martin Fiľko
Keyword(s):  
Magnetic Field ◽  
Spatial Distribution ◽  
Magnetic Fields ◽  
Spline Interpolation ◽  
Low Frequency ◽  
Fluxgate Magnetometer ◽  
Area Of Interest ◽  
Wide Range ◽  
Risk Areas ◽  
Python Programming

Unmanned aerial vehicles (UAVs) are used nowadays in a wide range of applications, including monitoring, mapping, or surveying tasks, involving magnetic field mapping, mainly for geological and geophysical purposes. However, thanks to the integration of ultrasound-aided navigation used for indoor UAV flight planning and development in sensorics, the acquired magnetic field images can be further used, for example, to enhance indoor UAV navigation based on the physical quantities of the image or for the identification of risk areas in manufacturing or industrial halls, where workers can be exposed to high values of electromagnetic fields. The knowledge of the spatial distribution of magnetic fields can also provide valuable information from the perspective of the technical cleanliness. This paper presents results achieved with the original fluxgate magnetometer developed and specially modified for integration on the UAV. Since the magnetometer had a wider frequency range of measurement, up to 250 Hz, the DC (Direct Current) magnetic field and low frequency industrial components could be evaluated. From the obtained data, 3D magnetic field images using spline interpolation algorithms written in the Python programming language were created. The visualization of the measured magnetic field in the 3D plots offer an innovative view of the spatial distribution of the magnetic field in the area of interest.

scholarly journals Magnetic Field Mapping and Correction for Moving OP-MEG

2021 ◽  
Author(s):  
Stephanie J Mellor ◽  
Tim M Tierney ◽  
George C O'Neill ◽  
Nicholas Alexander ◽  
Robert A Seymour ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Brain Activity ◽  
Low Frequency ◽  
Optically Pumped ◽  
Magnetic Field Mapping ◽  
Modelling Method ◽  
Movement Artefact ◽  
Power Spectral ◽  
Background Magnetic Field ◽  
The Magnetic Field

Background: Optically pumped magnetometers (OPMs) have made moving, wearable magnetoencephalography (MEG) possible. The OPMs typically used for MEG require a low background magnetic field to operate, which is achieved using both passive and active magnetic shielding. However, the background magnetic field is never truly zero Tesla, and so the field at each of the OPMs changes as the participant moves. This leads to position and orientation dependent changes in the measurements, which manifest as low frequency artefacts in MEG data. Objective: We modelled the spatial variation in the magnetic field and used the model to predict the movement artefact found in a dataset. Methods: We demonstrate a method for modelling this field with a triaxial magnetometer, then showed that we can use the same technique to predict the movement artefact in a real OPM-based MEG (OP-MEG) dataset. Results: Using an 86-channel OP-MEG system, we found that this modelling method maximally reduced the power spectral density of the data by 26.2 ± 0.6 dB at 0 Hz, when applied over 5 s non-overlapping windows. Conclusion: The magnetic field inside our state-of-the art magnetically shielded room can be well described by low-order spherical harmonic functions. We achieved a large reduction in movement noise when we applied this model to OP-MEG data. Significance: Real-time implementation of this method could reduce passive shielding requirements for OP-MEG recording and allow the measurement of low-frequency brain activity during natural participant movement.

scholarly journals On ion gyro-harmonic structuring in the stimulated electromagnetic emission spectrum during second electron gyro-harmonic heating

2012 ◽  
Vol 30 (11) ◽  
pp. 1587-1594 ◽  
Author(s):  
A. Samimi ◽  
W. A. Scales ◽  
P. A. Bernhardt ◽  
S. J. Briczinski ◽  
C. A. Selcher ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Frequency ◽  
Electromagnetic Emission ◽  
Spectral Lines ◽  
Critical Parameters ◽  
Pump Field ◽  
Pump Frequency ◽  
Ionospheric Heating ◽  
Background Magnetic Field ◽  
Stimulated Electromagnetic Emission

Abstract. Recent observations show that, during ionospheric heating experiments at frequencies near the second electron gyro-harmonic, discrete spectral lines separated by harmonics of the ion-gyro frequency appear in the stimulated electromagnetic emission (SEE) spectrum within 1 kHz of the pump frequency. In addition to the ion gyro-harmonic structures, on occasion, a broadband downshifted emission is observed simultaneously with these spectral lines. Parametric decay of the pump field into upper hybrid/electron Bernstein (UH/EB) and low-frequency ion Bernstein (IB) and oblique ion acoustic (IA) modes is considered responsible for generation of these spectral features. Guided by predictions of an analytical model, a two-dimensional particle-in-cell (PIC) computational model is employed to study the nonlinear processes during such heating experiments. The critical parameters that affect the spectrum, such as whether discrete gyro-harmonic on broadband structures is observed, include angle of the pump field relative to the background magnetic field, pump field strength, and proximity of the pump frequency to the gyro-harmonic. Significant electron heating along the magnetic field is observed in the parameter regimes considered.

scholarly journals Dynamics of the terrestrial radiation belts: a review of recent results during the VarSITI (Variability of the Sun and Its Terrestrial Impact) era, 2014–2018

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shrikanth Kanekal ◽  
Yoshizumi Miyoshi
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Ring Current ◽  
Plasma Waves ◽  
Radiation Belts ◽  
The Sun ◽  
Plasma Convection ◽  
Outer Radiation Belt ◽  
Inner Magnetosphere

AbstractThe Earth’s magnetosphere is region that is carved out by the solar wind as it flows past and interacts with the terrestrial magnetic field. The inner magnetosphere is the region that contains the plasmasphere, ring current, and the radiation belts all co-located within about 6.6 Re, nominally taken to be bounding this region. This region is highly dynamic and is home to a variety of plasma waves and particle populations ranging in energy from a few eV to relativistic and ultra-relativistic electrons and ions. The interplanetary magnetic field (IMF) embedded in the solar wind via the process of magnetic reconnection at the sub-solar point sets up plasma convection and creates the magnetotail. Magnetic reconnection also occurs in the tail and is responsible for explosive phenomena known as substorms. Substorms inject low-energy particles into the inner magnetosphere and help generate and sustain plasma waves. Transients in the solar wind such as coronal mass ejections (CMEs), co-rotating interaction regions (CIRs), and interplanetary shocks compress the magnetosphere resulting in geomagnetic storms, energization, and loss of energetic electrons in the outer radiation belt nad enhance the ring current, thereby driving the geomagnetic dynamics. The Specification and Prediction of the Coupled Inner-Magnetospheric Environment (SPeCIMEN) is one of the four elements of VarSITI (Variability of the Sun and Its Terrestrial Impact) program which seeks to quantitatively predict and specify the inner magnetospheric environment based on Sun/solar wind driving inputs. During the past 4 years, the SPeCIMEN project has brought together scientists and researchers from across the world and facilitated their efforts to achieve the project goal. This review provides an overview of some of the significant scientific advances in understanding the dynamical processes and their interconnectedness during the VarSITI era. Major space missions, with instrument suites providing in situ measurements, ground-based programs, progress in theory, and modeling are briefly discussed. Open outstanding questions and future directions of inner magnetospheric research are explored.

scholarly journals The BepiColombo–Mio Magnetometer en Route to Mercury

2020 ◽  
Vol 216 (8) ◽  
Author(s):  
W. Baumjohann ◽  
A. Matsuoka ◽  
Y. Narita ◽  
W. Magnes ◽  
D. Heyner ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Power Supply ◽  
Low Frequency ◽  
Internal Field ◽  
High Time Resolution ◽  
Fluxgate Magnetometer ◽  
Near Surface ◽  
The Magnetic Field ◽  
Low Frequency Waves ◽  
Inner Heliosphere

AbstractThe fluxgate magnetometer MGF on board the Mio spacecraft of the BepiColombo mission is introduced with its science targets, instrument design, calibration report, and scientific expectations. The MGF instrument consists of two tri-axial fluxgate magnetometers. Both sensors are mounted on a 4.8-m long mast to measure the magnetic field around Mercury at distances from near surface (initial peri-center altitude is 590 km) to 6 planetary radii (11640 km). The two sensors of MGF are operated in a fully redundant way, each with its own electronics, data processing and power supply units. The MGF instrument samples the magnetic field at a rate of up to 128 Hz to reveal rapidly-evolving magnetospheric dynamics, among them magnetic reconnection causing substorm-like disturbances, field-aligned currents, and ultra-low-frequency waves. The high time resolution of MGF is also helpful to study solar wind processes (through measurements of the interplanetary magnetic field) in the inner heliosphere. The MGF instrument firmly corroborates measurements of its companion, the MPO magnetometer, by performing multi-point observations to determine the planetary internal field at higher multi-pole orders and to separate temporal fluctuations from spatial variations.

scholarly journals High Bandwidth Measurements of Auroral Langmuir Waves with Multiple Antennas

2021 ◽  
Author(s):  
Chrystal Moser ◽  
James LaBelle ◽  
Iver H. Cairns
Keyword(s):  
Magnetic Field ◽  
Multiple Antennas ◽  
Low Frequency ◽  
Langmuir Wave ◽  
Wave Interaction ◽  
Lower Hybrid ◽  
Background Magnetic Field ◽  
Auroral Hiss ◽  
Plasma Line ◽  
High Bandwidth

Abstract. The High-Bandwidth Auroral Rocket (HIBAR) was launched from Poker Flat, Alaska on January 28, 2003 at 07:50 UT towards an apogee of 382 km in the night-side aurora. The flight was unique in having three high-frequency (HF) receivers using multiple antennas parallel and perpendicular to the ambient magnetic field, as well as very low frequency (VLF) receivers using antennas perpendicular to the magnetic field. These receivers observed five short-lived Langmuir wave bursts lasting from 0.1–0.2 s, consisting of a thin plasma line with frequencies in the range of 2470–2610 kHz that had an associated diffuse feature occurring 5–10 kHz above the plasma line. Both of these waves occurred slightly above the local plasma frequency with amplitudes between 1–100 μV/m. The ratio of the parallel to perpendicular components of the plasma line and diffuse feature were used to determine the angle of propagation of these waves with respect to the background magnetic field. These angles were found to be comparable to the theoretical Z-infinity angle that these waves would resonate at. The VLF receiver detected auroral hiss throughout the flight at 5–10 kHz, a frequency matching the difference between the plasma line and the diffuse feature. A dispersion solver, partially informed with measured electron distributions, and associated frequency- and wavevector-matching conditions were employed to determine if the diffuse features could be generated by a nonlinear wave-wave interaction of the plasma line with the lower frequency auroral hiss waves/lower-hybrid waves. The results show that this interpretation is plausible.

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