Abstract: A magnetic-field-measuring probe includes at least two magnetoresistive sensors which are sensitive to respective magnetic fields along a determined measurement axis. The at least two magnetoresistive sensors are rigidly connected to one another in a position such that the measurement axes thereof are at an angle other than zero. Output terminals specific to each magnetoresistive sensor are used to supply a signal that is representative of the field measured by each sensor along the measurement axis thereof. The difference between the derivative of a first magnetic field relative to a second direction and the derivative of a second magnetic field relative to a first direction is calculated to determine a component of current to be measured.

Abstract: A sensing apparatus includes a fluxgate module which outputs an analog signal corresponding to terrestrial magnetism using a fluxgate having a magnetic substance core and a driving coil, and an analog-to-digital (A/D) converter which converts an analog signal output from the fluxgate module into a digital signal. The fluxgate module includes first and second current amplifiers for exciting the magnetic substance core by applying pulses to first and second ends of the driving coil, and a pulse restricting part for driving the first and second current amplifiers to apply the pulses and for stopping driving the first and second current amplifiers when converting the analog signal into the digital signal is completed.

Abstract: An array of three-axis magnetometers used for dynamic magnetic anomaly compensation are located at the corners of a parallelopiped, with pairs of magnetometer outputs used to derive a magnetic anomaly gradient vector used to compensate a compass and/or the output of a gyroscope in an inertial management unit. The system may be used in a neutrally buoyant remotely operated vehicle to permit ascertaining of course and position in the absence of surface control signals.

Abstract: An array of induction magnetometers for use in airborne transient electromagnetic (ATEM) geophysical exploration is disclosed, having similar weight and external dimensions of prior art induction magnetometers but with improved signal strength, signal-to-noise ratio, higher frequency, self-resonance and bandwidth, and providing accurate and well monitored calibration.

Abstract: A measured physical quantity calculating part 41 calculates a measurement result-corrected value obtained by correcting a measurement result of a sensor unit 25 by the use of corrected values for the sensor unit 25. Subsequently, a measurement environment estimating part 42 estimates a terrestrial magnetism measurement environment on the basis of at least one measurement result-corrected value. The estimation result is displayed on a display unit 13 by an estimation result display part 43. In this way, the terrestrial magnetism measurement environment is first estimated and then the terrestrial magnetism is measured by the use of the sensor unit 25. That is, it is possible to measure the terrestrial magnetism by the use of a magnetic sensor mounted on a mobile information device after estimating the terrestrial magnetism measurement environment.

Abstract: A signal processing unit includes an integrating unit. The integrating unit is composed of a plurality of digital elements and is operative to integrate a detection signal over every quarter of one cycle of the detection signal to generate an integration value. The integration values to be generated are represented as S1, S2, S3, and S4. A calculating unit includes a plurality of digital elements and performs addition and subtraction on the generated integration values in accordance with the following equations used to calculate an in-phase component and a quadrature-phase component of (Ip=S4p?3+S4p?2?S4p?1?S4p) and (Qp=S4.4?S4p??S4p?1+S4p). Where Ip represents the in-phase component and Qp represents the quadrature-phase component. An amplitude obtaining unit obtains an amplitude of the detection signal based on the in-phase component and the quadrature-phase component.

Abstract: An integrated three-dimensional magnetic or any field sensing device and a method to fabricate an integrated three-dimensional magnetic sensing device is presented. An integrated three-dimensional magnetic sensing device comprises an apparatus that defines at least a first surface area and at least one sloped surface which is sloped with respect to the first surface area. Two magnetic sensing units could be arranged on the first surface area to provide first and second orthogonal sensing directions, and a third magnetic sensing unit could be arranged on the at least one sloped surface to provide sensing in at least a third sensing direction which is orthogonal to the first and second orthogonal sensing directions. Bias could be applied to the third magnetic sensing unit to cancel a component of the magnetic field sensed by the third magnetic sensing unit so that the third magnetic sensor unit only provides sensing in the third direction.

Abstract: A three-axis fluxgate-type circuit having three fluxgate sensors for outputting three analog voltage values respectively. A controller normalizes three digital voltage values corresponding to said three analog voltage values, select a set of linear voltage values from the three normalized digital voltage values and calculate an azimuth based on the set of linear voltage values.

Abstract: A magnetic azimuth measurement apparatus without arithmetic means nor any mechanical motion such as rotation, not affecting its mass production ability because of a simple configuration, and making it possible to measure a azimuth in higher precision, is provided. A trigger signal generates if a condition determining circuit detects that a switched output signal reaches a maximum (positive peak), and this trigger signal enables an output interface circuit to hold a switching signal. The switching signal held by the output interface circuit is a digital representation of a detection coil position parallel to an external magnetic field. Accordingly, it is possible to obtain the azimuth of the external magnetic field with respect to the sensor device.

Abstract: A three-dimensional magnetic bearing sensor 10a includes a first sensor 101, a second sensor 102, and a third sensor 103 each constituted by a magneto-impedance sensor element 10 comprising a magnetic sensitive member 2 having a characteristic changed responsive to an external magnetic field, an insulator 4 formed to allow penetration of the magnetic sensitive member 2 therethrough, and an electromagnetic coil 3 made up of foil-like conductive patterns 31, 32 arranged in adjacent relation on an outer surface of the insulator 4. The first sensor 101, the second sensor 102, and the third sensor 103 are disposed such that directions in which the magnetic sensitive members 2 in respective sensors have maximum magnetic field detection sensitivities are substantially orthogonal to each other.

Abstract: A sensor package comprising an X-axis sensor circuit component, a Y-axis sensor circuit component, and a Z-axis sensor circuit component, each mounted to a top surface of a rigid substrate. To minimize the height of the package, a channel is cut out of the top surface of the substrate in order to accommodate the Z-axis sensor component. On the Z-axis sensor component, input/output (I/O) pads are all arranged in an array along one edge of the sensor to conductively cooperate with I/O pads, or solder-filled vias, on the substrate located at a top edge of the channel. Once the sensors have all been mounted to the substrate, the package is encapsulated, and the overall height is less than 1.2 mm.

Abstract: A magnetism detecting device includes a magnetometric sensor, a bias magnetic field generating unit, a voltage applying unit, a detecting unit, and an operating unit. The detecting unit calculates a first output corresponding to a difference between two voltage values each corresponding to the positive and negative bias magnetic fields, and the positive voltage; and a second output corresponding to a difference between two voltage values each corresponding to the positive and negative bias magnetic fields, and the negative voltage. The detecting unit eliminates an offset voltage included in the first output and the second output by taking difference between the first output and the second output.

Abstract: A magnetic field sensor has a first sensor with an output for a first signal indicating a magnetic field acting in a plane, and a second sensor having an output for a second signal indicating a component of the magnetic field perpendicular to the plane. The first sensor and the second sensor are applied on a common substrate by means of planar process steps.

Abstract: The invention relates to a sensor for detecting the direction of a magnetic field in a plane whose direction can be defined by the indication of a polar angle ?. Said sensor comprises a number of n magnetic field sensors (3.0 to 3.7). A measurement axis (8.1 to 8.4) is assigned to each magnetic field sensor in such a manner that the absolute value of the output signal of the magnetic field sensor is largest when the magnetic field runs parallel to the measuring axis. All measuring axes intersect at a common point (5). The number k of measuring axes is equal to at least three. An operating mode is provided during which two magnetic field sensors are selected for calculating the angle ?. These two magnetic field sensors belong to different measuring axes, and the values of the output signals thereof are less than those of the output signals of the magnetic field sensors belonging to the other measuring axes.

Abstract: The inventive device for evaluating the sensor signal includes the provider for providing the sensor signal, the processor for processing the sensor signal and for providing an information signal comprising information regarding the amplitude course of the sensor signal and means for comparing the sensor signal to a first and a second comparison value, wherein the first and/or the second comparison value are adjustable based on the information signal such that a difference between the first and the second comparison value comprises a non-linear relation to the amplitude course of the sensor signal.

Abstract: A magneto impedance sensor element with electromagnetic coil comprised of: a terminal board on which an extended groove which extends in one direction has been formed; an electromagnetic coil, made with one part of the coil formed in a spiral shape inside the extended groove in the terminal board, and joined to each tip of that coil the other part of the coil placed across the top of the groove; insulating material placed in the extended groove on the terminal board; and a magnetic sensitive body inserted within the insulating material, to which either high frequency or pulse electic current is applied. When either high frequency or pulse electrical current is applied to the magnetic sensitive body, voltage is output from the above electromagnetic coil in response to the intensity of the external magnetic field which is generated in the electromagnetic coil.

Abstract: On a single chip are formed a plurality of magnetoresistance effect elements provided with pinned layers having fixed magnetization axes in the directions that cross each other. On a substrate 10 are formed magnetic layers that will become two magnetic tunnel effect elements 11, 21 as magnetoresistance effect elements. Magnetic-field-applying magnetic layers made of NiCo are formed to sandwich the magnetic layers in plan view. A magnetic field is applied to the magnetic-field-applying magnetic layers. The magnetic field is removed after the magnetic-field-applying magnetic layers are magnetized in the direction shown by arrow A.

Abstract: A magnetic sensor assembly comprising magnetic detection elements is provided. In a magnetic sensor assembly 100 according to the present invention, a magnetic detection element 140 is fixed to a base member 110 and, by having the base member 110 stand upright, it is possible to stand the magnetic detection element 140 upright. Thereby, it becomes easy to manufacture magnetic detection devices which detect three-axis components of terrestrial magnetism vector. In the base member 110, first terminals 120 are provided on a first surface 112 whereas second terminals 124 are provided on a second surface 114. The first terminals 120 are electrically connected with electrodes of the magnetic detection element 140 whereas the second terminals 124 are electrically connected to external wires.

Abstract: Certain embodiments of the present invention provide a system and method for electromagnetic tracking using a single-coil transmitter. The system includes a single coil transmitter emitting a signal, a receiver receiving a signal from the single coil transmitter, and electronics for processing the signal received by the receiver. The electronics determine a position of the single coil transmitter. The transmitter may be a wireless or wired transmitter. The receiver may be a printed circuit board. In an embodiment, the receiver may be a twelve receiver circuit printed circuit board including single coils and/or pairs of coils. The electronics may determine position, orientation, and/or gain of the transmitter.

Abstract: A scanning magnetic microscope SMM (20) includes a sensor (10) for sensing a magnetic field generated by a specimen (78), the sensor including one of a MTJ, a GMR, or an EHE sensor; translation apparatus (22A–C, 52) for translating the sensor relative to a surface of sad specimen; and a data processor (50), having an input coupled to an output of said sensor, for constructing an image of said magnetic field. The sensor preferably includes one to three sensing units each defining a sensing axis for sensing a component of a magnetic field from a specimen, the sensing units disposed such that the sensing axes are orthogonal to one another. Pluralities of such sensors can be disposed in two or three dimensional arrays. The SMM can be used for examining the current flow in ICs, electromigration, magnetic data storage media, biomagnetic systems and magnetic ink used to print currency.

Abstract: A compact sensor system integrates electric and/or magnetic field sensors to accurately measure, with a high level of sensitivity, one or more electric and magnetic vector components of fields. The electric and magnetic field data can be utilized separately or combined. The sensor system is self-contained so as to include a built-in power source, as well as data storage and/or transmission capability. The integrated sensor system also preferably includes a global positioning system (GPS) to provide timing and position information, a sensor unit which can determine the orientation and tilt of the sensor system, and self-calibrating structure which produces local electric and/or magnetic fields used to calibrate the sensor system following deployment.

Abstract: An integrated three-dimensional magnetic or any field sensing device and a method to fabricate an integrated three-dimensional magnetic sensing device is presented. An integrated three-dimensional magnetic sensing device comprises an apparatus that defines at least a first surface area and at least one sloped surface which is sloped with respect to the first surface area. Two magnetic sensing units could be arranged on the first surface area to provide first and second orthogonal sensing directions, and a third magnetic sensing unit could be arranged on the at least one sloped surface to provide sensing in at least a third sensing direction which is orthogonal to the first and second orthogonal sensing directions. Bias could be applied to the third magnetic sensing unit to cancel a component of the magnetic field sensed by the third magnetic sensing unit so that the third magnetic sensor unit only provides sensing in the third direction.

Abstract: A control device 200 calibrates a magnetic-field sensor 100 by computation. A computation unit 210 calculates the magnetic-field intensity based upon the outputs of X-axis, Y-axis, and Z-axis magnetic-field detection devices of the magnetic-field sensor 100. Such calculation is performed for four or more different points. The calculation is performed such that at least one point is not positioned on a plane including the other points. The computation unit 210 converts the outputs from the X-axis, Y-axis, and Z-axis magnetic-field detection devices of the magnetic-field sensor 100 into three-dimensional spatial coordinate points. Then, the computation unit 210 creates a sphere on which the four or more coordinate points thus obtained are positioned. The coordinate point of the center of the sphere thus created represents the magnetic-field offset.

Abstract: Methods and apparatus for vertical chip-on-board sensor packages can comprise a vertical sensor circuit component comprising a first face, a second face, a bottom edge, a top edge, two side edges, input/output (I/O) pads and at least one sensitive direction wherein the I/O pads are arranged near the bottom edge. Such vertical die chip-on-board sensor packages can also comprise one or more horizontal sensor circuit components comprising a top face, a printed circuit board (PCB) mounting face, a vertical sensor circuit component interface edge, two or more other edges, and one or more sensitive directions wherein the vertical sensor circuit component interface edge supports the vertical sensor circuit component along the Z axis and conductively or non-conductively connects to the vertical sensor circuit component.

Abstract: A magnetic sensor includes a thin deformable membrane made of a conductive material forming a first plate of a capacitor which conducts an electric current therethrough. A second capacitor plate of the capacitor includes a doped region of a semiconductor substrate. A layer of a gaseous dielectric separates the two plates. The membrane deforms due to the effect of the Lorentz force generated by a magnetic field lying in the plane of the membrane and perpendicular to the lines of current being conducted therethrough. In addition, a process for fabricating this magnetic sensor is also provided as well as a device for measuring a magnetic field using the magnetic sensor.

Abstract: Two sensor units are formed from magnetoresistive material. Elements of the first sensor unit have a total anisotropy field in a first direction. Elements of the second sensor unit have a total anisotropy field in a second direction. An integral coil sets a direction of magnetization in the elements of the first and second sensor units. An output of the first sensor unit is representative of magnetic field components perpendicular to the first direction and an output of the second sensor is representative of magnetic field components perpendicular to the second direction.

Abstract: In order to improve the speed of an electro-magnetic field intensity calculation process in a device capable of performing the cooperation process of a circuit analysis and an electro-magnetic wave analysis, the present invention comprises a determination unit 2 for determining whether a component constituting an electric circuit contained in an analysis target, an analysis processing unit 3 for analyzing an electro-magnetic wave emitted from the analysis target, using an analysis target model containing a linear component if all components are linear, and a cooperation process unit 4 for dividing the analysis target into a circuit analysis model to which a circuit analysis method should be applied, an electro-magnetic wave analysis model to which an electro-magnetic wave analysis should be applied and one or more ports for combining the two models and analyzing an electro-magnetic wave emitted from the analysis target, if one or more components are non-linear.

Abstract: A composite shell adapted to cover a source or sensor, particularly for subsurface applications. The shell provides transparency to the passage of signals to or from the source or sensor. The shell is adapted with a uniform semi-conductive surface providing a path for electric currents flowing within a subsurface borehole to short near the source or sensor.

Abstract: In a magnetic sensor device, a positioning element is provided with receptacles for receiving one magnetic field sensor element each. The positioning element and the magnetic field sensor elements are manufactured in a way that they fit exactly together so that the positioning element exactly positions the sensor elements with respect to each other. The magnetic field sensor elements may be manufactured separately before they are put together to build the magnetic field sensor device.

Abstract: In an apparatus for measuring a specific absorption rate (SAR) for use in a radio apparatus, a first near magnetic field of a radio wave radiated from a reference radio apparatus is measured in free space, and an SAR of the radio wave radiated from the reference radio apparatus by using a predetermined phantom according to a predetermined measurement method. A transformation factor ? is calculated by dividing the measured SAR by a square value of the measured first near magnetic field, and a second near magnetic field of a radio wave radiated from a radio apparatus to be measured is measured in free space. Then an SAR of the radio wave radiated from the radio apparatus to be measured is estimated and calculated by multiplying a square value of the measured second near magnetic field by the calculated transformation factor ?.

Abstract: The present invention is a magnetic field detection device that makes use of a frequency characteristic affording circuit in order to selectively detect magnetic signals from a frequency domain accurately at a high level of sensitivity. The present invention has a magneto-impedance element, a detector coil and a negative feedback coil which is wound around the magneto-impedance element, and a frequency characteristic affording circuit which affords a frequency characteristics on the negative feedback signal of a negative feedback connecting an output terminal thereof with the negative feedback coil. Using filters as the frequency characteristic affording circuit, the following are possible uses of this magnetic field detection device: a geomagnet detection device for earthquake prediction (using a high-pass filter), a bill validation apparatus for vending machines, etc. (using a low-pass filter), and a magnetic oscillation detection device for a magnetic gate system (using a band-reject filter).

Abstract: A device for the detection of movement of a valuable object, for example in a museum in which a device for detecting at least a rotation of the object, and particularly magnetometers or inclinometers, are mechanically fixed to the object. These detecting devices are coupled to a message transmission device that sends a presence message as long as detection has not taken place and an alert type message when detection has taken place. A monitoring station processes these messages or the absence of these messages, to trigger an alert if necessary.

Abstract: An electromagnetic wave measuring apparatus includes a loop probe section having loop probes whose loop planes are placed so as to be perpendicular to each other, and each loop probe is placed so that its magnetic field detection space is not interfered with by other loop probes. If the loop probe section is placed at measurement position coordinates xi, yj, it detects a magnetic field component at the measurement position coordinates xi, yj, which is parallel to an XY plane, and a magnetic field component in a Z-axis direction at measurement position coordinates xi, yj?1, and repeats measurement by pitch p in a positive Y-axis direction. By calculating the root sum square of the detection results at each measurement position coordinate, a three-dimensional magnetic field level of an object to be measured can be obtained at each measurement position coordinate as electromagnetic field distribution with high-precision.

Abstract: The invention relates to a method and device by means of which the location and position of an object may be determined in relation to another object by electromagnetic signals. In the arrangement in accordance with the invention there are two objects to the one of which there are attached signal sources, i.e. transmitters that generate electromagnetic signals, and the other object contains one or more receivers for measuring the transmitter signals. Usually the object containing transmitters is the one whose location or position is of interest and which is the object of the measurement. For example, in MEG measurements the object associated with the transmitters is the head of a human being on whose surface the transmitters are placed. By means of the arrangement in accordance with the invention is possible to find out the location and position of the head, in which case the location of the signals generated by the brain may be found out and utilized when examining the brain activity.

Abstract: A magnetic sensor of an electronic instrument has a circular or substantially circular component that assumes magnetism in the vicinity of its circumference. An X axis magnetic sensor detects a magnetic field component in the X axis direction that is arranged in a position inside the vicinity of the circumference of the component, or is arranged such that a detection axis of the magnetic sensor overlaps an X axis passing through the center of the component in an arbitrary position on the X axis or on its extended line. A Y axis magnetic sensor detects a magnetic component in a Y axis direction that is arranged inside the vicinity of the circumference of the component, or is arranged such that a detection axis of the magnetic sensor overlaps a Y axis passing through the center of the component and perpendicular to the X axis in an arbitrary position on the Y axis or on its extended line. A correcting circuit corrects the signals outputted from the X axis magnetic sensor and the Y axis magnetic sensor.

Abstract: The present invention is a two-dimensional magnetic sensor having a first magneto-impedance sensor element including a first magneto-sensitive element and a first electro-magnetic coil which is wound around said first magneto-sensitive element; a second magneto-impedance sensor element including a second magneto-sensitive element and a second electro-magnetic coil which is wound around said second magneto-sensitive element; and an integrated circuit including an oscillator, a current switching element, a voltage detector, and an amplifier.

Abstract: A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter a controlled area. The device comprises a screening portal, including multiple sensor arrays and associated electronics. The device places the sensor arrays in close proximity to a subject's body, including the head and feet if desired, for screening purposes. The portal can have multiple excitation sources oriented to generate a multi-axis excitation field, and multi-axis sensors. The portal can also have an interlock with the door of the controlled area.

Abstract: A method and apparatus for interrogating a sample that exhibits molecular rotation are disclosed. In practicing the method, the sample is placed in a container having both magnetic and electromagnetic shielding, and Gaussian noise is injected into the sample. An electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Guassian noise is detected, and this signal is used to generate a spectral plot that displays, at a selected power setting of the Gaussian noise source, low-frequency spectral components characteristic of the sample in a selected frequency range between DC and 50 kHz. In one embodiment, the spectral plot that is generated is a histogram of stochastic resonance events over the selected frequency range. From this spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated are identified.

Abstract: An electromagnetic wave measuring apparatus includes a loop probe section having loop probes 11a to 11c whose loop planes are placed so as to be perpendicular to each other, and each loop probe is placed so that its magnetic field detection space is not interfered with by other loop probes. If the loop probe section is placed at measurement position coordinates xi, yj, it detects a magnetic field component at the measurement position coordinates xi, yj, which is parallel to an XY plane, and a magnetic field component in a Z-axis direction at measurement position coordinates xi, yj−1, and repeats measurement by pitch p in a positive Y-axis direction. By calculating the root sum square of the detection results at each measurement position coordinate, a three-dimensional magnetic field level of an object to be measured can be obtained at each measurement position coordinate as electromagnetic field distribution with high-precision.

Abstract: A Position Sensor comprises: one or more excitation windings; a signal generator adapted to apply excitation signals to the or each excitation winding; tag means displaceable relative to said excitation windings; one or more sensor windings electromagnetically coupled to said excitation windings such that in response to said excitation signals being applied to said excitation windings, there is generated sensed signal in the or each sensor winding; and a signal processor adapted to process said sensed signals to determine the position of said tag means in any location in the X, Y and Z planes essentially in accordance with phase values or in accordance with phase values and amplitude values.

Abstract: The present invention provides an electromagnetic tracking system that includes a field generator and a field sensor arranged to generate and detect, respectively, an electromagnetic field. Both the transmitter and receiver coils are connected to signal conditioning and processing circuitry to provide outputs indicative of the coil signals. A processor operates on the signals to determine the coordinates of the sensing assembly relative to the generator assembly. The signal processor produces ratiometric outputs, and applies a mutual inductance model to solve for position/orientation coordinates. In some embodiments, a disturber in the form of a conductive ring or a sheath is disposed about an interfering piece of equipment to moderate and standardize disturbances due to eddy currents.

Abstract: Control apparatus for a horizontal boring tool is described which drives a boring lance via boring rods. The tool includes an input interface for receiving actual values of controlled variables of the horizontal boring tool, and an output unit for issuing control signals for controlling the horizontal boring tool. Between the input interface and the output unit is provided a fuzzy control unit which determines the control signals for activation of the horizontal boring tool from the actual values of the controlled variables and the desired values for the controlled variables by fuzzy logic while taking into account heuristic process values. The control apparatus permits automatic operation of the horizontal boring tool with good course steering and high precision.

Abstract: A magnetic azimuth measurement apparatus without arithmetic means nor any mechanical motion such as rotation, not affecting its mass production ability because of a simple configuration, and making it possible to measure a azimuth in higher precision, is provided. A trigger signal generates if a condition determining circuit detects that a switched output signal reaches a maximum (positive peak), and this trigger signal enables an output interface circuit to hold a switching signal. The switching signal held by the output interface circuit is a digital representation of a detection coil position parallel to an external magnetic field. Accordingly, it is possible to obtain the azimuth of the external magnetic field with respect to the sensor device.

Abstract: A bounding box or volume of interest is flooded with a modulated AC electromagnetic signal from a source. Different types of modulated signals may be used, including single-tone AM and FM. One or more sensors disposed on an object or body within the volume are then used to detect the signal, and a digital and/or analog spectral and phase analysis is performed on the received signal in hardware or software. The processing distinguishes between the direct source to sensor response and the response due to eddy currents. By removing the response due to the distorters, the effects of the electromagnetic distortion can be removed through a more conventional “free-space” solution. The invention finds applicability in a wide variety of environments, including head tracking systems and helmet-mounted displays for fighter aircraft; head trackers for armored vehicles; medical-guided surgery and biopsy; remote sensing, among other potential uses.

Abstract: An integrating magnetic sensor is described which comprises a sensor element made from a filament of substantially amorphous material which exhibits giant magneto-impedance and means for applying a bias field to the said sensor element so that it operates in the high field section of the giant magneto-impedance response.

Abstract: A bounding box or volume of interest is flooded with a modulated AC electromagnetic signal from a source. Different types of modulated signals may be used, including single-tone AM and FM. One or more sensors disposed on an object or body within the volume are then used to detect the signal, and a digital and/or analog spectral and phase analysis is performed on the received signal in hardware or software. The processing distinguishes between the direct source to sensor response and the response due to eddy currents. By removing the response due to the distorters, the effects of the electromagnetic distortion can be removed through a more conventional “free-space” solution. The invention finds applicability in a wide variety of environments, including head tracking systems and helmet-mounted displays for fighter aircraft; head trackers for armored vehicles; medical-guided surgery and biopsy; remote sensing, among other potential uses.

Abstract: An eddy current probe comprising two solenoid coils wound around a common rectangular wafer base of high permeability material extending beyond the coils at wafer corners with the wafer becoming the solenoid core. Posts also of high permeability material depend from a wafer front at its corners with coils crossing orthogonally on the wafer. The coils are connected to alternating current to produce magnetic fields that have like magnetic poles at wafer corners diagonally opposed across the wafer, the coils switching in phase to alternate the magnetic field between posts at base diagonal corners. With the posts at the wafer base corners, the combined magnetic fields generated from the orthogonal coils conduct through the posts and emanate from post ends. The post ends have a curvature matching that of a material to be tested for better coupling the magnetic field into the material.

Abstract: Gradiometers are encompassingly disposed, relative to an object of interest, in a configuration generally describing a closed prolate spheroidal shape, and the measurements taken by the gradiometers are mathematically processed. The gradiometric measurements are defined as directional derivatives which exist in equations involving directional derivatives and prolate spheroidal multipole moments of said entity. The prolate spheroidal multipole moments are thereby calculated, and these prolate spheroidal multipole moment values are extrapolated to ascertain the magnetic fields (equivalently expressed, the magnetic signatures) associated with the object and inwardly delimited by the prolate spheroid. The practitioner can optimize such distribution numerically, orientationally and/or positionally by using the equations involving directional derivatives and prolate spheroidal multipole moments. Extraneous magnetic field effects (e.g.

Abstract: The invention relates to a device for long-term recording of strong magnetic fields. This device comprises a magnetic field sensor as well as an analyser unit that forms signals characterising the effects of the magnetic fields from the sensor signals by integration or differentiation, and that stores these signals optionally in a memory or displays, by means of a signalling unit, that a limit has been exceeded.

Abstract: A magnetic pick-up coil for measuring magnetic field with high specific sensitivity, optionally with an electrostatic shield (24), having coupling elements (22) with high winding packing ratio, oriented in multiple directions, and embedded in ceramic material for structural support and electrical insulation. Elements of the coil are constructed from green ceramic sheets (200) and metallic ink deposited on surfaces and in via holes of the ceramic sheets. The ceramic sheets and the metallic ink are co-fired to create a monolithic hard ceramic body (20) with metallized traces embedded in, and placed on exterior surfaces of, the hard ceramic body. The compact and rugged coil can be used in a variety of environments, including hostile conditions involving ultra-high vacuum, high temperatures, nuclear and optical radiation, chemical reactions, and physically demanding surroundings, occurring either individually or in combinations.