Direct determination of the local ionospheric Hall conductance distribution from Two-dimensional electric and magnetic field data: Application of the method using models of typical ionospheric electrodynamic situations

1995 ◽  
Vol 100 (A11) ◽  
pp. 21473-21488 ◽  
Author(s):  
Olaf Amm
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Direct Determination ◽  
Two Dimensional ◽  
Hall Conductance ◽  
Magnetic Field Data ◽  
Data Application ◽  
Electric And Magnetic Field ◽  
Conductance Distribution

scholarly journals Electromagnetic field observations by the DEMETER satellite in connection with the 2009 L'Aquila earthquake

2018 ◽  
Vol 36 (5) ◽  
pp. 1483-1493 ◽  
Author(s):  
Igor Bertello ◽  
Mirko Piersanti ◽  
Maurizio Candidi ◽  
Piero Diego ◽  
Pietro Ubertini
Keyword(s):  
Magnetic Field ◽  
Seismic Activity ◽  
Field Data ◽  
Satellite Orbit ◽  
Relative Energy ◽  
Analysis Tool ◽  
Magnetic Field Data ◽  
Demeter Satellite ◽  
2009 L’Aquila Earthquake ◽  
Electric And Magnetic Field

Abstract. To define a background in the electromagnetic emissions above seismic regions, it is necessary to define the statistical distribution of the wave energy in the absence of seismic activity and any other anomalous input (e.g. solar forcing). This paper presents a completely new method to determine both the environmental and instrumental backgrounds applied to the entire DEMETER satellite electric and magnetic field data over L'Aquila. Our technique is based on a new data analysis tool called ALIF (adaptive local iterative filtering, Cicone et al., 2016; Cicone and Zhou, 2017; Piersanti et al., 2017b). To evaluate the instrumental background, we performed a multiscale statistical analysis in which the instantaneous relative energy (ϵrel), kurtosis, and Shannon entropy were calculated. To estimate the environmental background, a map, divided into 1∘×1∘ latitude–longitude cells, of the averaged relative energy (ϵrel‾), has been constructed, taking into account the geomagnetic activity conditions, the presence of seismic activity, and the local time sector of the satellite orbit. Any distinct signal different (over a certain threshold) from both the instrumental and environmental backgrounds will be considered as a case event to be investigated. Interestingly, on 4 April 2009, when DEMETER flew exactly over L'Aquila at UT = 20:29, an anomalous signal was observed at 333 Hz on both the electric and magnetic field data, whose characteristics seem to be related to pre-seismic activity.

scholarly journals The Mie representation for Mercury’s magnetic field

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
S. Toepfer ◽  
Y. Narita ◽  
K. -H. Glassmeier ◽  
D. Heyner ◽  
P. Kolhey ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Least Square ◽  
Simulation Code ◽  
Magnetic Field Data ◽  
Least Square Fit ◽  
High Precision Determination ◽  
The Magnetic Field ◽  
Magnetospheric Field

AbstractThe parameterization of the magnetospheric field contribution, generated by currents flowing in the magnetosphere is of major importance for the analysis of Mercury’s internal magnetic field. Using a combination of the Gauss and the Mie representation (toroidal–poloidal decomposition) for the parameterization of the magnetic field enables the analysis of magnetic field data measured in current carrying regions in the vicinity of Mercury. In view of the BepiColombo mission, the magnetic field resulting from the plasma interaction of Mercury with the solar wind is simulated with a hybrid simulation code and the internal Gauss coefficients for the dipole, quadrupole and octupole field are reconstructed from the data, evaluated along the prospective trajectories of the Mercury Planetary Orbiter (MPO) using Capon’s method. Especially, it turns out that a high-precision determination of Mercury’s octupole field is expectable from the future analysis of the magnetic field data measured by the magnetometer on board MPO. Furthermore, magnetic field data of the MESSENGER mission are analyzed and the reconstructed internal Gauss coefficients are in reasonable agreement with the results from more conventional methods such as the least-square fit.

scholarly journals Magnetic properties of CHAMP and their effects on in-orbit calibration

2013 ◽  
Vol 2 (1) ◽  
pp. 9-17 ◽  
Author(s):  
H. Lühr ◽  
F. Yin ◽  
R. Bock
Keyword(s):  
Magnetic Field ◽  
Magnetic Moment ◽  
Field Data ◽  
Field Vector ◽  
Current Strength ◽  
Fluxgate Magnetometer ◽  
Vector Data ◽  
Magnetic Field Data ◽  
Average Current

Abstract. CHAMP has so far been the most successful magnetic field mission. For achieving that, special effort had to be invested in building a magnetically clean spacecraft. The magnetic moment of the spacecraft is about 1 Am2. In this article we introduce a new method that allows the determination of the magnetic moment during the mission from the average current strength of the magneto-torquers. In order to achieve precise field vector data, the readings of the fluxgate magnetometer are routinely calibrated against the absolute Overhauser measurements. A reanalysis of all the magnetic field data is performed which takes also into account small disturbances from the power system. Uncertainties of the final magnetic field data are estimated to be of the order of 0.1 nT.

scholarly journals Electromagnetic field observations by the DEMETER satellite in connection with the 2009 L’Aquila earthquake

2018 ◽  
Author(s):  
Igor Bertello ◽  
Mirko Piersanti ◽  
Maurizio Candidi ◽  
Piero Diego ◽  
Pietro Ubertini
Keyword(s):  
Magnetic Field ◽  
Seismic Activity ◽  
Field Data ◽  
Satellite Orbit ◽  
Relative Energy ◽  
Analysis Tool ◽  
Magnetic Field Data ◽  
Demeter Satellite ◽  
2009 L’Aquila Earthquake ◽  
Electric And Magnetic Field

Abstract. To define a background in the electromagnetic emissions above seismic regions, it is necessary to define the statistical distribution of the wave energy in absence of seismic activity and any other anomalous input (e.g. solar forcing). This paper presents a completely new method to determine both the environmental and instrumental background applied to the entire DEMETER satellite electric and magnetic field data over L’Aquila. Our technique is based on a new data analysis tool called ALIF (Adaptive Local Iterative Filtering, [Cicone et al., 2016 and 2017; Piersanti et al., 2017]). To evaluate the instrumental noise, we performed a multiscale statistical analysis, in which the instantaneous relative energy (ϵrel), kurtosis and Shannon entropy was calculated. To estimate the environmental noise, a background map, divided into 1° × 1° latitude/longitude cells, of the averaged relative energy (ϵrel) has been constructed, taking into account the geomagnetic activity conditions, the presence of seismic activity and the local time sector of the satellite orbit. Any distinct signal different (over a certain threshold) from both the instrumental and environmental backgrounds will be considered as a case event to be investigated. Interestingly, on April 4, 2009, when DEMETER flew exactly over L’Aquila at UT = 20:29, an anomalous signal was observed at 333 Hz on both the electric and magnetic field data, whose characteristics seem to be related to pre-seismic activity.

An Augmented Iteratively Re-weighted and Refined Least Squares Method for lp Minimization Problem in Inverse Modeling of Potential Field Magnetic Data

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Maysam Abedi
Keyword(s):  
Magnetic Field ◽  
Magnetic Susceptibility ◽  
Least Squares ◽  
Minimization Problem ◽  
Potential Field ◽  
Field Data ◽  
Least Squares Method ◽  
Porphyry Copper ◽  
Magnetic Data ◽  
Magnetic Field Data

The presented work examines application of an Augmented Iteratively Re-weighted and Refined Least Squares method (AIRRLS) to construct a 3D magnetic susceptibility property from potential field magnetic anomalies. This algorithm replaces an lp minimization problem by a sequence of weighted linear systems in which the retrieved magnetic susceptibility model is successively converged to an optimum solution, while the regularization parameter is the stopping iteration numbers. To avoid the natural tendency of causative magnetic sources to concentrate at shallow depth, a prior depth weighting function is incorporated in the original formulation of the objective function. The speed of lp minimization problem is increased by inserting a pre-conditioner conjugate gradient method (PCCG) to solve the central system of equation in cases of large scale magnetic field data. It is assumed that there is no remanent magnetization since this study focuses on inversion of a geological structure with low magnetic susceptibility property. The method is applied on a multi-source noise-corrupted synthetic magnetic field data to demonstrate its suitability for 3D inversion, and then is applied to a real data pertaining to a geologically plausible porphyry copper unit.  The real case study located in  Semnan province of  Iran  consists  of  an arc-shaped  porphyry  andesite  covered  by  sedimentary  units  which  may  have  potential  of  mineral  occurrences, especially  porphyry copper. It is demonstrated that such structure extends down at depth, and consequently exploratory drilling is highly recommended for acquiring more pieces of information about its potential for ore-bearing mineralization.

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