The position of a magnetic target can be obtained through magnetic anomaly which is measured by a magnetic sensor. Comparing with vector magnetic sensor, the measurement value of the scalar magnetic sensor is almost not influenced by its orientation in measurement coordinate axes. Therefore, scalar magnetic sensors can be easily assembled into an array. Based on analysis of the total scalar mag...

Three-dimensional (3D) knee angle measurement is one of the key measures in human gait analysis. Inertial sensor capable measuring joint motion under unconstrained conditions a practical tool for clinical evaluation and rehabilitation. An inertial unit (IMU) consisting accelerometer gyroscope allows orientation 3D with an additional (i.e., magnetometer). However, ferromagnetic interference nega...

In an evanescent wave magnetometer the Zeeman polarization is probed at micrometer to submicrometer distances from the cell surface. The electron paramagnetic resonance lines of an evanescent wave magnetometer in the presence of a magnetic field gradient exhibit edge enhancement seen previously in nuclear magnetic resonance lines. We present a theoretical model that describes quantitatively the...

A sensor system for an underwater vehicle is described. The vehicle is equipped with inclinometers, gyroscopes, a magnetometer, a pressure gauge, and a sonar system. The sensor models used for the inclinometers and gyroscopes are straightforward; however, the magnetometer can be corrupted by variations in the earth’s field caused by: external objects and internal magnetic fields. We show how to...

Multichannel superconducting quantum interference device (SQUID) systems based on double relaxation oscillation SQUIDs (DROS) were developed for measuring magnetocardiography (MCG) and magnetoencephalography (MEG) signals. Since DROS provides large fluxto-voltage transfer coefficients, about 10 times larger than the DC SQUIDs, direct readout of the SQUID output was possible using compact roomte...

The calibration parameters of a vector magnetometer are estimated only by the use of a scalar reference magnetometer. The method presented in this paper differs from those previously reported in its linearized parametrization. This allows the determination of three offsets or signals in the absence of a magnetic field, three scale factors for normalization of the axes and three non-orthogonalit...