scholarly journals Ørsted satellite captures high-precision geomagnetic field data

Eos ◽  
2001 ◽  
Vol 82 (7) ◽  
pp. 81-88 ◽  
Author(s):  
Torsten Neubert ◽  
M. Mandea ◽  
G. Hulot ◽  
R. von Frese ◽  
F. Primdahl ◽  
...  
Keyword(s):  
High Precision ◽  
Geomagnetic Field ◽  
Field Data

scholarly journals A High-Precision Magnetic-Assisted Heading Angle Calculation Method Based on a 1D Convolutional Neural Network (CNN) in a Complicated Magnetic Environment

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 642
Author(s):  
Guanghui Hu ◽  
Hong Wan ◽  
Xinxin Li
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
High Precision ◽  
Geomagnetic Field ◽  
Field Data ◽  
Time Window ◽  
Magnetic Data ◽  
Navigation Systems ◽  
Pedestrian Navigation ◽  
Heading Angle

Due to its widespread presence and independence from artificial signals, the application of geomagnetic field information in indoor pedestrian navigation systems has attracted extensive attention from researchers. However, for indoors environments, geomagnetic field signals can be severely disturbed by the complicated magnetic, leading to reduced positioning accuracy of magnetic-assisted navigation systems. Therefore, there is an urgent need for methods which screen out undisturbed geomagnetic field data for realizing the high accuracy pedestrian inertial navigation indoors. In this paper, we propose an algorithm based on a one-dimensional convolutional neural network (1D CNN) to screen magnetic field data. By encoding the magnetic data within a certain time window to a time series, a 1D CNN with two convolutional layers is designed to extract data features. In order to avoid errors arising from artificial labels, the feature vectors will be clustered in the feature space to classify the magnetic data using unsupervised methods. Our experimental results show that this method can distinguish the geomagnetic field data from indoors disturbed magnetic data well and further significantly improve the calculation accuracy of the heading angle. Our work provides a possible technical path for the realization of high-precision indoor pedestrian navigation systems.

scholarly journals The geomagnetic field at 1982 from DE-2 and other magnetic field data.

1988 ◽  
Vol 40 (9) ◽  
pp. 1103-1127 ◽  
Author(s):  
R. A. LANGEL ◽  
J. R. RIDGWAY ◽  
M. SUGIURA ◽  
K. MAEZAWA
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Field Data ◽  
Magnetic Field Data

scholarly journals Geomagnetic anomaly associated with Fukushima earthquake on February 13th, 2021

2021 ◽  
Vol 331 ◽  
pp. 07012
Author(s):  
Cipta Ramadhani ◽  
Bulkis Kanata ◽  
Abdullah Zainuddin ◽  
Rosmaliati ◽  
Teti Zubaidah
Keyword(s):  
Data Processing ◽  
Geomagnetic Field ◽  
Field Data ◽  
Low Frequency ◽  
Earthquake Precursors ◽  
Polarization Ratio ◽  
Magnetic Polarization ◽  
Central Frequency ◽  
Electromagnetic Data ◽  
Geomagnetic Anomaly

In this study, we performed research on electromagnetic anomalies related to earthquakes as early signs (precursors) that occurred in Fukushima, Japan on February 13th, 2021. The research focused on the utilization of geomagnetic field data which was derived from the Kakioka (KAK), Kanoya (KNY), and Memambetsu (MMB) observatories, particularly in the ultra-low frequency (ULF) to detect earthquake precursors. The method of electromagnetic data processing was conducted by applying a polarization ratio. In addition, we improved the methodology by splitting the ULF data (which ranged from 0.01-0.1 Hz) into 9 central frequencies and picking up the highest value from each central frequency to get the polarization ratio. The anomaly of magnetic polarization was identified 2-3 weeks before the mainshock in a narrowband frequency in the range of 0.04-0.05 Hz.

scholarly journals Magnetic local time dependence of geomagnetic disturbances contributing to the AU and AL indices

2011 ◽  
Vol 29 (4) ◽  
pp. 673-678 ◽  
Author(s):  
S. Tomita ◽  
M. Nosé ◽  
T. Iyemori ◽  
H. Toh ◽  
M. Takeda ◽  
...  
Keyword(s):  
Local Time ◽  
Geomagnetic Field ◽  
Field Data ◽  
Geomagnetic Latitude ◽  
Magnetic Activity ◽  
Auroral Zone ◽  
Magnetic Local Time ◽  
Geomagnetic Disturbances ◽  
Current Systems ◽  
Local Time Dependence

Abstract. The Auroral Electrojet (AE) indices, which are composed of four indices (AU, AL, AE, and AO), are calculated from the geomagnetic field data obtained at 12 geomagnetic observatories that are located in geomagnetic latitude (GMLAT) of 61.7°–70°. The indices have been widely used to study magnetic activity in the auroral zone. In the present study, we examine magnetic local time (MLT) dependence of geomagnetic field variations contributing to the AU and AL indices. We use 1-min geomagnetic field data obtained in 2003. It is found that both AU and AL indices have two ranges of MLT (AU: 15:00–22:00 MLT, ~06:00 MLT; and AL: ~02:00 MLT, 09:00–12:00 MLT) contributing to the index during quiet periods and one MLT range (AU: 15:00–20:00 MLT, and AL: 00:00–06:00 MLT) during disturbed periods. These results are interpreted in terms of various ionospheric current systems, such as, Sqp, Sq, and DP2.

scholarly journals Enhancing Performance of Magnetic Field Based Indoor Localization Using Magnetic Patterns from Multiple Smartphones

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2704 ◽  
Author(s):  
Imran Ashraf ◽  
Soojung Hur ◽  
Yongwan Park
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Field Data ◽  
Performance Comparison ◽  
Magnetic Sensors ◽  
Location Based Services ◽  
Field Pattern ◽  
Magnetic Field Data ◽  
Localization Performance ◽  
The Magnetic Field

Wide expansion of smartphones triggered a rapid demand for precise localization that can meet the requirements of location-based services. Although the global positioning system is widely used for outdoor positioning, it cannot provide the same accuracy for the indoor. As a result, many alternative indoor positioning technologies like Wi-Fi, Bluetooth Low Energy (BLE), and geomagnetic field localization have been investigated during the last few years. Today smartphones possess a rich variety of embedded sensors like accelerometer, gyroscope, and magnetometer that can facilitate estimating the current location of the user. Traditional geomagnetic field-based fingerprint localization, although it shows promising results, it is limited by the fact that various smartphones have embedded magnetic sensors from different manufacturers and the magnetic field strength that is measured from these smartphones vary significantly. Consequently, the localization performance from various smartphones is different even when the same localization approach is used. So devising an approach that can provide similar performance with various smartphones is a big challenge. Contrary to previous works that build the fingerprint database from the geomagnetic field data of a single smartphone, this study proposes using the geomagnetic field data collected from multiple smartphones to make the geomagnetic field pattern (MP) database. Many experiments are carried out to analyze the performance of the proposed approach with various smartphones. Additionally, a lightweight threshold technique is proposed that can detect user motion using the acceleration data. Results demonstrate that the localization performance for four different smartphones is almost identical when tested with the database made using the magnetic field data from multiple smartphones than that of which considers the magnetic field data from only one smartphone. Moreover, the performance comparison with previous research indicates that the overall performance of smartphones is improved.

NanoMagSat, a 16U nanosatellite constellation high-precision magnetic project to initiate permanent low-cost monitoring of the Earth’s magnetic field and ionospheric environment

2021 ◽  
Author(s):  
Gauthier Hulot ◽  
Jean-Michel Léger ◽  
Lasse B. N. Clausen ◽  
Florian Deconinck ◽  
Pierdavide Coïsson ◽  
...  
Keyword(s):  
High Precision ◽  
Geomagnetic Field ◽  
Low Cost ◽  
Low Noise ◽  
Low Earth Orbit ◽  
Dual Frequency ◽  
Observatory Data ◽  
Vector Magnetometer ◽  
Gnss Receivers ◽  
Global Coverage

<p>The geomagnetic field has been continuously monitored from low-Earth orbit (LEO) since 1999, complementing ground-based observatory data by providing calibrated scalar and vector measurements with global coverage. The successful three-satellite ESA Swarm constellation is expected to remain in operation up to at least 2025. Further monitoring the field from space with high-precision absolute magnetometry beyond that date is of critical importance for improving our understanding of dynamics of the multiple components of this field, as well as that of the ionospheric environment. Here, we will report on the latest status of the NanoMagSat project, which aims to deploy and operate a new constellation concept of three identical 16U nanosatellites, using two inclined (approximately 60°) and one polar LEO, as well as an innovative payload including an advanced Miniaturized Absolute scalar and self-calibrated vector Magnetometer (MAM) combined with a set of precise star trackers (STR), a compact High-frequency Field Magnetometer (HFM, sharing subsystems with the MAM), a multi-needle Langmuir Probe (m-NLP) and dual frequency GNSS receivers. The data to be produced will at least include 1 Hz absolutely calibrated and oriented magnetic vector field (using the MAM and STR), 2 kHz very low noise magnetic scalar (using the MAM) and vector (using the HFM) field, 2 kHz local electron density (using the m-NLP) as well as precise timing, location and TEC products. In addition to briefly presenting the nanosatellite and constellation concepts, as well as the evolving programmatic status of the mission (which already underwent a consolidation study funded by the ESA Scout programme), this presentation will illustrate through a number of E2E simulations the ability of NanoMagSat to complement and improve on many of the science goals of the Swarm mission at a much lower cost, and to bring innovative science capabilities for ionospheric investigations. NanoMagSat could form the basis of a permanent collaborative constellation of nanosatellites for low-cost long-term monitoring of the geomagnetic field and ionospheric environment from space.</p>

Development of mobile platform for indoor positioning reference map using geomagnetic field data

2018 ◽  
Vol 68 ◽  
pp. 557-569 ◽  
Author(s):  
He Huang ◽  
Dong Ha Lee ◽  
Kun Chang ◽  
Wei Li ◽  
Tri Dev Acharya
Keyword(s):  
Geomagnetic Field ◽  
Field Data ◽  
Indoor Positioning ◽  
Mobile Platform ◽  
Reference Map
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