Simulation Analysis of Magnetic Gradient Full-Tensor Measurement System

The magnetic gradient full-tensor measurement system is diverse, and the magnetometer array structure is complex. Aimed at the problem, seven magnetic gradient full-tensor measurement system models are studied in detail. The full-tensor measurement theories of the tensor measurement arrays are analyzed. Under the same baseline distance, the magnetic dipole model is used to simulate the measurement system. Based on different measurement systems, the paper quantitatively compares and analyzes the error of the structure. A more optimized magnetic gradient full-tensor measurement system is suggested. The simulation results show that the measurement accuracy of the planar measurement system is slightly higher than that of the stereo measurement system. Among them, the cross-shaped and square measurement systems have relatively smaller structural errors and higher measurement accuracy.

A new wearable multichannel magnetocardiogram system with a SERF atomic magnetometer array

In this study, a wearable multichannel human magnetocardiogram (MCG) system based on a spin exchange relaxation-free regime (SERF) magnetometer array is developed. The MCG system consists of a magnetically shielded device, a wearable SERF magnetometer array, and a computer for data acquisition and processing. Multichannel MCG signals from a healthy human are successfully recorded simultaneously. Independent component analysis (ICA) and empirical mode decomposition (EMD) are used to denoise MCG data. MCG imaging is realized to visualize the magnetic and current distribution around the heart. The validity of the MCG signals detected by the system is verified by electrocardiogram (ECG) signals obtained at the same position, and similar features and intervals of cardiac signal waveform appear on both MCG and ECG. Experiments show that our wearable MCG system is reliable for detecting MCG signals and can provide cardiac electromagnetic activity imaging.

Preliminary investigation of the possibility of GIC development in Greece

<p>Geomagnetically Induced Currents (GIC) constitute an integral part of the space weather research and a subject of ever-growing attention for countries located in the low and middle latitudes. A series of recent studies highlights the importance of considering GIC risks for the Mediterranean region. The HellENIc GeoMagnetic Array (ENIGMA) is a network of 4 ground-based magnetometer stations in the areas of Thessaly, Central Greece, Peloponnese and Crete in Greece that provides geomagnetic measurements for the study of pulsations, resulting from the solar wind - magnetosphere coupling. ENIGMA magnetometer array enables effective remote sensing of geospace dynamics and the study of space weather effects on the ground (i.e. GIC). ENIGMA contributes data to SuperMAG, a worldwide collaboration of organizations and national agencies that currently operate approximately 300 ground-based magnetometers. In this presentation, we exploit ENIGMA data in order to study the spatio-temporal variations of the geomagnetic field that emanate during active geospace conditions. Moreover, we investigate the possibility that these variations produce hazardous currents and provide an estimation of their intensity, focusing on the most intense magnetic storms of the present solar cycle.</p>