Magnetic Data Acquisition System Research Articles

Application of toroidal magnet excitation and hall sensor array in magnetic leakage field detection of rail surface defect

To detect rail top surface defects, NdFeB toroidal permanent magnets were firstly used to excite the rail detection area, and the magnetic excitation direction was perpendicular to the rail direction. So that, the magnetic circuit can be analyzed, and the model was verified by finite element simulation. Secondly, the artificial rectangular defect samples were machined on the top surface of the rail, and the magnetic field data acquisition system was developed and equipped on the inspection vehicle. With that, a linear array which consisted of three-dimensional hall sensors was designed to detect the magnetic leakage field signal from the defect samples. Finally, the features of the leakage field signal in each dimension were extracted. And then, the length, width, and depth of the defects were predicted using BP neural network algorithm. The results indicate that the method can improve the excitation efficiency, and the average absolute errors of prediction for defect length, width, and depth were 1.43 mm, 1.01 mm, and 0.63 mm respectively.

Radio-frequency measurements of energetic-electron-driven emissions using high-frequency magnetic probe on XuanLong-50 spherical torus

A high-frequency magnetic probe is designed and developed on the XuanLong-50 (EXL-50) spherical torus to measure high-frequency magnetic field fluctuation. The magnetic loop, radio filters, radio-frequency limiter, and data acquisition system of the probe are comprehensively examined. The fluctuation data from the EXL-50 plasma are analyzed in the time–frequency domain using fast Fourier transforms. Moreover, distinct high-frequency instabilities are detected using this diagnostic system. In particular, significant frequency chirping is observed, which is consistent with the bump-on-tail drive instability predicted using the Berk–Breizman model.

Preliminary Modelling of Solar Quiet Geomagnetic Field Average using Non-Linear Autoregressive with Exogeneous Input (NARX)

This paper discusses geomagnetic field attempt modelling using an Artificial Neural Network (ANN). The local horizontal component of geomagnetic field data was collected on April 2011 (equinox) during a solar quiet day at recent solar cycle inclination-24 using the Magnetic Data Acquisition System (MAGDAS) in Langkawi, Malaysia, in the low latitude region. The calculated average values (mean) of the H component geomagnetic field variation during Equinox 2011 characterised the dominant geomagnetic field during that particular solar cycle. The difference in amplitude of maximum and minimum values shows a regular diurnal variation of the geomagnetic field during Sq inthe low latitude region. The output training utilised these calculated mean values during the modelling attempt. Meanwhile, the input training utilised proton density, solar wind plasma speed, plasma flow pressure, and Interplanetary Magnetic Field (IMF) space data using Non-Linear Auto Regressive Input (NARX). The best modelling outputs were 3, 2, and 3 for input delay (𝑛𝑢), output delay (𝑛y), and hidden layer size (h), respectively. Residual test and model fit analysis show an unbiased and high overlap between predicted and actual geomagnetic field average values, suggesting the model can potentially anticipate the geomagnetic field average during solar quiet in November (month of Equinox) on solar cycle inclination.

Designing a Magnetic Measurement Data Acquisition and Control System With Reuse in Mind: A Rotating Coil System Example

Accelerator magnet test facilities frequently need to measure different magnets on differently equipped test stands and with different instrumentation. Designing a modular and highly reusable system that combines flexibility built-in at the architectural level as well as on the component level addresses this need. Specification of the backbone of the system, with the interfaces and dataflow for software components and core hardware modules, serves as a basis for building such a system. The design process and implementation of an extensible magnetic measurement data acquisition and control system are described, including techniques for maximizing the reuse of software. The discussion is supported by showing the application of this methodology to constructing two dissimilar systems for rotating coil measurements, both based on the same architecture and sharing core hardware modules and many software components. The first system is for production testing 10 m long cryo-assemblies containing two MQXFA quadrupole magnets for the high-luminosity upgrade of the Large Hadron Collider and the second for testing IQC conventional quadrupole magnets in support of the accelerator system at Fermilab.

ULF geomagnetic anomaly associated with the Sumatra-Pagai Islands earthquake swarm during 2020

Observations of earthquake precursors via geomagnetic anomalies from ultra-low frequency (ULF) could provide an expectation for short-term earthquake prediction. However, there are still several obstacles in determining this precursor, one of which is the presence of a precursor bias if the earthquake occurs at a close time and location. To cope with this problem, we analysed six earthquakes with a magnitude >5 on Pagai Island, Mentawai, Sumatra, during 2020. These earthquakes have epicentres close to each other and occur within a short time (one month). This study used geomagnetic data recorded by the Magnetic Data Acquisition System (MAGDAS) magnetometer network at Sicincin station (SCN), West Sumatra, and Kepahiyang station (KPY), Bengkulu, with a span of one month before the earthquake. The anomaly of ULF emission was analysed using the power spectral density method at a frequency of 0.012 Hz for the H and Z components of the geomagnetic data. The onset time of the ULF emission anomaly was determined by the standard deviation value (pz + σ, pz – σ) of the SZ/SH power ratio polarization. The disturbance storm time index (Dst) was used to ensure that the anomaly occurred was not caused by geomagnetic storm. Also, the single station transfer function was used to calculate the azimuth, and the empirical formula between the anomaly amplitude and the magnitude was used to calculate the earthquake magnitude as the validation of the anomaly source. Several ULF anomalies as earthquake precursors were observed, especially at the KPY station. The estimated azimuth shows a good accuracy compared to the earthquake's azimuth, with an average value of 97.8%. Furthermore, the earthquake magnitude calculated from the ULF anomaly shows a good agreement with the actual earthquake magnitude, with an average accuracy of 98.13%.

Magnetic Data Acquisition System (MAGDAS) Malaysia: Installation and Performance Analysis of Local Data Logger with Kyushu University Data Logger at USM Transkrian, Pulau Pinang

Magnetic Data Acquisition System (MAGDAS) is a magnetometer that originated from the International Centre for Space and Weather Science and Education at Kyushu University, Japan, to study space weather. The latest real-time Magnetic Data Acquisition System/Circum-pan Pacific Magnetometer Network (MAGDAS/CPMN) was installed at the West Coast Universiti Sains Malaysia Engineering Campus, Pulau Pinang, Malaysia. This is the seventh Magnetometer installed under MAGDAS network by Kyushu University in Malaysia (geographic latitude and longitude: 5.117N, 100.00E and geomagnetic latitude and longitude: 4.32S, 173.07E). The magnetic field component represents earth's geomagnetic field by MAGDAS. There is three main magnetic field component which describes the magnetic field which is Horizontal Intensity (H-component), Declination (D-component) and Vertical Component (Z-component). The strength of the earth's magnetic field can be monitored through the magnetometer installed at the targeted location and the value of the magnetic field can be compared with the World Magnetic Map (WMM) or any local magnetometer station in the region the installed magnetometer. This paper studies/narrates the deployment and performance analysis of the newly installed MAGDAS using Local and Kyushu Data Logger at the University Sains Malaysia. The deployment of the magnetometer is referenced with the magnetometer data logger from the Kyushu Universities. The magnetometer. The Kyushu University data logger deployment is becoming a benchmark for localizing the data logger developed locally.

Characterization of seasonal and annual variation of horizontal component of magnetic field in africa and asia regions

This study considered the horizontal component of the magnetic field, H, which is a characteristic of Equatorial Electrojet (EEJ). Using Magnetic Data Acquisition System (MAGDAS) data preserved for the year 2009, variations in H strength were determined in 10 stations in Africa and Asia sector. The seasonal and annual fluctuations in the H-component of the Earth’s magnetic field were studied using hourly data of the horizontal magnetic field component. For the hourly fluctuation, the baseline values of H were estimated using the average values around local midnight hours between 2300 and 0200 local-time (LT) and subtracted from other hourly values; for seasonal and yearly analysis, the monthly and annual averages were computed. In all seasons, seasonal variations were higher in equatorial stations than in anti-equatorial stations, while maximum values of SqH were recorded in the equinoctial season, with an annual highest peak value of 70.96 nT in Langkawi (LKW; 6.30°S, 99.78°E) and the lowest peak value of 27.45 nT in Cooktown (CKT; 15.48°N, 145.25°E) both at 1300 LT.

THE STUDY OF LONGITUDINAL AND LATITUDINAL VARIATION OF EQUATORIAL ELECTROJET SIGNATURE AT STATIONS WITHIN THE 96°MM AND 210°MM AFRICAN AND ASIAN SECTORS RESPECTIVELY UNDER QUIET CONDITIONS.

Solar quiet current (S_q) and Equatorial Electrojet (EEJ) are two current systems which are produced by electric current in the ionosphere. The enhancement of the horizontal magnetic field is the EEJ. This research is needed for monitoring equatorial geomagnetic current which causes atmospheric instabilities and affects high frequency and satellite communication. This study presents the longitudinal and latitudinal variation of equatorial electrojet signature at stations within the 96°mm and 210°mm African and Asian sectors respectively during quiet condition. Data from eleven observatories were used for this study. The objectives was to determine the longitudinal and latitudinal geomagnetic field variations during solar quiet conditions, Investigate monthly variation and diurnal transient seasonal variation; Measure the strength of the EEJ at stations within the same longitudinal sectors and find out the factors responsible for the longitudinal and latitudinal variation of EEJ. Horizontal (H) component of geomagnetic field for the year 2008 from Magnetic Data Acquisition System (MAGDAS) network were used for the study. The International Quiet Days (IQDs) were used to identify quiet days. Daily baseline values for each of the geomagnetic element H were obtained. The monthly average of the diurnal variation was found. The seasonal variation of dH was found. Results showed that: The longitudinal and latitudinal variation in the dH differs in magnitude from one station to another within the same longitude due to the difference in the influence of the EEJ on them.

Characterization of magnetic field horizontal component in selected stations along the 210o MM

Characterizing the magnetic field horizontal component (H) variability helps to better accommodate the irregular fluctuations inthe electron/ion density of the ionosphere for mitigating short-wave radio communication and Global Navigation Satellite Systems (GNSS) disruptions. This study employed three year data (2007-2009) from Magnetic Data Acquisition System (MAGDAS) facilities at six (6) observatories along the 210o magnetic meridian (MM) for investigating hourly, seasonal and annual variations in the horizontal component of the Earth’s magnetic field. The baseline value of H was computed from its average value near local midnight hours between 2400 and 0100 local time (LT) and subtracted from other hours value for the hourly variation; while the monthly and annual averages were computed for seasonal and yearly analysis respectively. Results indicates that maximum values of Sq are recorded in equinoctial season with an annual peak value of 70.96 nT for year 2009 recorded at Langkawi (LKW) as against the lowest peak value of 27.45 nT recorded in Cooktown (CKT) at 1300LT.
 Keywords: Magnetic field, horizontal component, solar quiet, seasonal variation, solar equinox

Installation and preliminary data analysis of Penang magnetic data Acquisition system (MAGDAS) in Malaysia

MAGDAS PEN was established on 19th September 2019 as one of the MAGDAS observatory arrays located at Universiti Sains Malaysia (USM) (5.15°, 100.50°). The main objective of the MAGDAS project is to monitor global electromagnetic and the ambient plasma density in the geospace environment. This installation has contributed to a better understanding of the Sun-Earth coupling system. This paper presents the installation process of one of the MAGDAS magnetometers named YU-8 T magnetic sensor and provides a preliminary analysis of geomagnetic HDZ components amplitude-time that was observed at PEN station. A one-month HDZ-geomagnetic field data was processed from 1st November to 30th November 2019. The daily variations with a consistent pattern in delta H geomagnetic field components are observed throughout the day with eastward electric field effects that are observed during solar peak hours. The delta H-component gradually increases around 0700LT and reaches the maximum reading at 1300LT with a range of value ~ 40-70nT. The value slowly decreases that started from 1400LT until the night time. The reading during the night time shows a constant variation with magnitude varies in between −10nT to + 10nT. The average H-component value of the night time is used as the baseline for the observation system. Overall, the observed trends portray a good sign of solar quiet field and Sq with no solar-terrestrial disturbances.

Development of the Cloud-Based Magnetic Data Acquisition System for Real Time Geomagnetic Monitoring

Magnetic Data Acquisition System (MAGDAS) is a system of a real-time magnetometer data logger deployed by Kyushu Sangyo University of Fukuoka, Japan as part of Japan’s leading contribution to International Heliophysical year of the United Nations. This paper proposed a cloud-based MAGDAS for the YU-8T magnetometer. MAGDAS is the system that measures and monitors the earth’s magnetic field or geomagnetic field. Converting the old system to the new system will provide the capability to monitor the magnetic field changes continuously due to the solar activities which are harmful to the electrical appliances. To verify the workability of the system, the data from the MAGDAS Langkawi and solar event was gathered to be compared with the developed system. The location where the measurement takes place is at Pusat Sukan UiTM Shah Alam, Selangor, Malaysia (geographic latitude and longitude: 3.00N, 101.00E, and geomagnetic latitude and longitude: 6.37S, 173.65E. This project consists of the YU-8T magnetometer system, hardware, software, and cloud-based web-server. YU-8T magnetometer measures the voltage of Earth’s magnetic field in the form of H, D and Z parameters to be stored in the data logger. The stored data was transferred to the cloud-based web-server through the Internet of Thing (IoT) for real-time monitoring.

English

Variations of equatorial electrojet (EEJ) in six Magnetic Data Acquisition System (MAGDAS) stations (four stations within the magnetic equator region and two stations outside the region) on the 210oMagnetic Meridian (MM) chain were examined. Data of hourly values of horizontal component of magnetic field, H in the year 2007 for Cooktown (CKT), Amami-oh-Shima (AMA), Davao (DAV), Langkawi (LKW), Yap- Island (YAP) and Cebu (CEB) were used in the study. The electrojet current was studied using both the estimation method and Fambitakoye simulation model to determine the correlation between their results. The strength of equatorial electrojet in the stations were estimated with respect to Cooktown (CKT; 15.48°N, 145.25°E), a station located outside the electrojet region. The maximum electrojet strength was observed in the month of March in Davao (DAV), Cebu (CEB) and Langkawi (LKW) with values of 107.5, 88.5 and 64.08 nT, respectively. The model simulation of EEJ current presents maximum values of 237.9, 207 and 160 nT in DAV, CEB and LKW, respectively in the same month. This result establishes a similarity in the performance of the methods but with higher values in the model performance. A linear correlation analysis between them showed average correlation coefficient values of 0.81 in Yap-Island (YAP), 0.84 in LKW, 0.6 in DAV and 0.54 in CEB. The data also show variability in EEJ, with results showing higher EEJ current magnitude for stations closer to the dip equator. The Root Mean Square Error (RMSE) was carried out to determine the suitability of the model for in the four seasons for each station. Result shows that the model performed better for March equinox in Cebu (3.58) and Yap-Island (5.97), December solstice (8.96) and September equinox in Davao and Langkawi (6.55), respectively. Key words: Equatorial electrojet, dip equator, magnetic data acquisition system (MAGDAS), Fambitakoye model, E-region, solar quiet.

Pattern of Ionization Gradient, Solar Quiet Magnetic Element, and F2‐Layer Bottomside Thickness Parameter at African Equatorial Location

AbstractThe study of ionization gradient (dN/dh) profile in the description of ionospheric dynamics is not common. This is the first attempt at finding the dependence of ionization gradient, solar quiet component (Sq (BH)), and bottomside thickness parameter (B0) in the African equatorial sector. Digisonde and Magnetic Data Acquisition System data collocated at an equatorial location were employed. Result was presented for sunrise (00 LT), midday (12 LT), sunset (18 LT), and midnight (00 LT) hours. The ionization gradient peak height remains unchanged at midday across all months. A percentage correlation of 93% existed in the inverse and direct linear relationship of dN/dh‐B0 at sunrise, and of Sq (BH)‐B0 at midday, respectively. Significant relationship between dN/dh and Sq (BH) was at sunset; for other hours, the relationship is poor. The multiple linear relationship of dN/dh‐Sq (BH)‐B0 parameters revealed that the dependence of dN/dh on Sq (BH) and B0 is highest at midday, and a model equation was presented. The dependence of dN/dh on the solar activity index (F10.7) holds at all the selected hours, and distinct only at midday and midnight for the Sq (BH)‐F10.7 and B0‐F10.7 patterns. Both the peak ionization gradient and the height it occurs maximizes/minimizes at 18 LT/06 LT. The importance of the F region dynamo at heights above 150 km was reported.

Features of horizontal magnetic field intensity over northern island of Malaysia

This study utilized magnetic field records of the horizontal component obtained from magnetic data acquisition system at northern island of Malaysia to delineate the diurnal variations of SqH and their monthly mean MSqH for a period of 4 years. The results show that for the entire period of study, the daytime SqH amplitudes increase from $$\sim 20$$ to $$\sim 160$$ nT and their MSqH amplitudes increased from $$\sim 40$$ to about 135 nT in 2008 to 2013, respectively. These variabilities of SqH and MSqH reached peak amplitudes between 10:00 and 12:00 LT hrs. The standard deviation fairly responds to the daily variability of SqH with a phase shift in January 2008 and 2013 which may likely have connection to the sudden stratospheric warming event that occurred in these months. We observed the extension of eastward field that continued beyond the sunset (18:00 LT) hours is more prevalent with higher magnitudes during the deep minimum solar activity and the probable causes are discussed. The observed counter equatorial electrojet associated with late reversal of night-time westward electric field (WEF) shows inverse relationship with increasing solar activity and those that are not associated to late reversal of night-time WEF seems to indicate linear relationship exception of deep minimum solar activity year (2008). We also observed a gradual shift of ECEJ to the morning sector with increasing solar activity. Throughout the years, days with stronger morning counter equatorial electrojet magnitudes generally weaken the expected strong eastward current and shifted its peak to earlier local time. The annual and seasonal variations of SqH show semiannual variation with equinoctial maxima and solstitial minima. About 40% of the SqH shows positive night-time to pre-sunrise variations which suggest the existence of weak electric currents not necessarily of ionospheric origin with appreciable influence at this longitude sector. The extension of eastward field beyond the sunset hours suggests likely modification of the evening side ionosphere over this region.

Assessment of the Geomagnetically Induced Current (GIC) at Low Latitude Region based on MAGDAS Data

The geomagnetically induced current (GICs) impact is no longer concentrated at high latitude region strictly. The objective of this study was to extend the GICs observation conducted at equatorial region using geomagnetic data extracted from magnetometer installed at Langkawi National Observatory (LNO), Malaysia for the long-term analysis involving the solar cycle 24. The observation is now continued with the GICs comparison between LKW stations with five low latitude station which is BCL, PTN, MND, DAW, and TWV obtained from the magnetic data acquisition system (MAGDAS). The assessment of the GICs behavior revealed the possibility of LKW station experiences GICs is high, based on the time derivative of the horizontal component (dH/dt) value. Extend from that, the GICs estimation was successful done by applying the plane wave method as a model to calculate the North-South and the East-West component, Ex and Ey respectively. The equation of the GICs was provided by excluding the topology constant parameters, which is a and b constant and the value of the underground conductivity for low latitude station. Subsequently, the comparison was limited in years of 2008 – 2014 due to insufficient geomagnetic data. Indeed, the GICs calculation is able to derive the GICs estimation and showed a good agreement with the corresponding value of the time derivative of the horizontal component. However, the accurate current value (A) is able to gain by conducting a direct measurement of the high voltage power transmission system.

The Response of Geomagnetic H and Z Components During X-Class Solar Flare

This paper presents the study of solar flare effects (SFE) on H and Z components of the geomagnetic field. The raw data of H and Z components are extracted from Magnetic Data Acquisition System (MAGDAS) at Langkawi station (LKW:6.3°, 99.78°) and INTERMAGNET website for Lanzhou (LZH: 36.1°,103.84°) and Yakutsk (YAK: 61.96°,129.66°) stations. There are eight (8) events of X-class solar flares from 2011 to 2014 were selected to shows the changes and enhancement of H and Z components with different latitudes. The regression analysis is used to prove the correlation between the enhancement of geomagnetic field and the x-ray flux. The statistical results show the ratios of Δ HSFE/Δ H0 and Δ ZSFE/Δ Z0 is greater than zero for all stations and proven the SFE has affected the H and Z components and not just an augmentation of pre-flare ionospheric currents.

The first solar-powered Magdas-9 installation and possible geomagnetically induced currents study at Johor, Malaysia

The Magnetic Data Acquisition System (MAGDAS-9) was successfully installed at Universiti Teknologi MARA Johor, Pasir Gudang Campus, Malaysia (JOH station), under the joint collaboration between International Center for Space Weather Science and Education (ICSWSE), National Space Agency (ANGKASA) and UiTM Johor. This is the first solar-powered magnetometer under the Magnetic Data Acquisition System of Circum-pan Pacific Magnetometer Network (MAGDAS/CPMN). In this paper, construction process, installation process and analysis of first geomagnetic observations at MAGDAS JOH station are presented. In addition, analysis on time derivative of horizontal component of geomagnetic field (dH/dt) to indicate the possibility of Geomagnetically Induced Currents (GIC) occurrences is also presented in this paper. The obtained geomagnetic components: H, D, Z and Total F are approximately similar to World Magnetic Model 2015 (WMM2015) while the diurnal variation from this geomagnetic observation showing a good variation pattern. The analysis of dH/dt has indicated 2 significant events of GIC.

The First Solar Flare Effect Observation at UiTM-SID Station during Solar Cycle 23-24

International Heliophysical Year (IHY; 2007-2009) has a remarkable impact on space and earth electromagnetism research and society. For Malaysian perspectives, it acts as a spiral point to the expanding of space weather-related research. The research activities involve installation of real-time Magnetic Data Acquisition System of Circum-pan Pacific Magnetometer Network, i.e. MAGDAS/CPMN for space weather study and application, which was deployed for the IHY; 2007-2009. In addition to MAGDAS system, to understand the characteristics of the lower ionospheric layer (60-150km) during space weather events, a Very Low Frequency (VLF) monitoring system has been developed. The MAGDAS and VLF monitoring system called UiTM-SID are located at Universiti Pendidikan Sultan Idris, UPSI (3.71’, 101.53’), Malaysia. The first observation effects of solar flare during November 2016 to March 2017, for the period of a minimum solar cycle 23-24 have been examined on sub-ionospheric VLF signals from VTX4 (19.2 kHz) and NWC (19.8 kHz) transmitter monitored at UPSI. In general, the level of amplitude reading for VTX4 signals is higher than NWC signals for quite diurnal variations. The effects of the solar flare class C7.5 on 29th November 2016 shows an enhancement of amplitude due to increase in the lower region electron density by the radiation of solar flare. The average daily amplitude reading was compared to the average value of solar flare event, the result shows the percentage difference is 12% increased in VTX4 and NWC signals.

Design of inductive sensors and data acquisition system for diagnostics of magnetohydrodynamic instabilities on the T-15MD tokamak

Magnetic diagnostics plays an important role in tokamak operation. Magnetic data are used for the real-time control of plasma current, shape and position and for post-discharge analysis of magnetohydrodynamic (MHD) plasma instabilities and equilibrium reconstruction. The magnetic diagnostic of the T-15MD will consist of more than 350 inductive sensors of various types. Location and number of sensors is determined by the measured physical value.The data acquisition system must simultaneously provide both the real-time data transfer of some sensors to the control loop and all sensors data storage for subsequent analysis. The requirements for the data acquisition depend on the data destination. For the data transferred to the control loop is sufficient to have a sampling rate up to 10 kHz, but this data must be transferred and processed in real-time mode. At the same time, for the study of fast processes (disruptions, tearing modes, Alfvén eigenmodes), sensor signals should be acquired with a sampling rate from 100 kHz to 2 MHz and transferred to the database in about 3 min after discharge.The article describes the construction and location of inductive sensors, as well as the peculiarity of the magnetic diagnostics data acquisition system.

Magnetic Data Acquisition System (MAGDAS) Malaysia: installation and preliminary data analysis at ESERI, UNISZA

Magnetic Data Acquisition System (MAGDAS) is a magnetometer initiated by the International Center for Space Weather Science and Education in Kyushu University, Japan, to study space weather. The latest of real-time Magnetic Data Acquisition System/Circum-pan Pacific Magnetometer Network was successfully installed at the East Coast Environmental Research Institute in Universiti Sultan Zainal Abidin, Terengganu, Malaysia, by Kyushu University. This is the fifth magnetometer under the MAGDAS network (geographic latitude and longitude: 5.23°, 103.04° and geomagnetic latitude and longitude: − 4.21°, 175.91°). In this study, the results of data plot obtained at Terengganu (TRE) station were shown to have reliable patterns of geomagnetic elements. The amplitude variations for each component were also proximate with other stations and a standard model. This study compared MAGDAS-II data for the H component with solar wind data (input energy, IMF, dynamic pressure and speed).