Abstract: A communication device for estimating the azimuth angle includes a receiving module and an estimating module. The receiving module is configured to sequentially switch several azimuth angles to receive a first signal transmitted at the first transmitting angle from a first transmitting module of the first communication device. The estimation module is configured to calculate several signal powers of the first signal received by the receiving module at the several azimuth angles; to determine the maximum signal power among the several signal powers; to determine the pre-judged AOD according to the azimuth angle of the maximum signal; and to calculate the AOD of the associated first signal based on the pre-judged AOD and at least one azimuth angle adjacent to the pre-judged AOD among the several azimuth angles.

Abstract: A system may include a sensor a visual capturing device, and a controller. The sensor may be configured to measure a value associated with an input. The visual capturing device may be configured to capture visual data. The controller may be configured to cause the measured value and the captured visual data to be rendered on a display device simultaneously.

Abstract: According to the invention, the system comprises: at least three position beacons (3) arranged about said location (2) and emitting in the long-wave range, and an apparatus associated with the user (1) and including means for receiving, processing and displaying the information transmitted by said beacons (3).

Abstract: An apparatus for direction finding a received radio signal is enclosed. The receiving apparatus selectively receives on a predetermined frequency to match the transmitter frequency. The receiving apparatus is comprised of one non directional antenna and two or more loop antennas. The loop antennas modify the field of the incident radio signal by absorbing the incident radio frequency energy to create a non-ambiguous gain pattern on the sense antenna that can be used to determine the direction of the incident RF signal.

Abstract: Magnetic tracking systems and methods for determining the position and orientation of a remote object. A magnetic tracking system includes a stationary transmitter for establishing a reference coordinate system, and at least one receiver. The remote object is attached to, mounted on, or otherwise coupled to the receiver. The transmitter can include a set of three mutually perpendicular coils having a common center point, or a set of three coplanar coils with separate centers. The receiver can include a set of three orthogonal coils. The position and orientation of the receiver and the remote object coupled thereto is determined by measuring the nine mutual inductances between the three transmitter coils and the three receiver coils. The magnetic tracking system provides reduced power consumption, increased efficiency, digital compensation for component variation, automatic self-calibration, automatic synchronization with no connections between transmitter and receiver, and rapid low-cost implementation.

Abstract: An image compression apparatus includes: first and second imaging sections for capturing an image of a subject to generate first and second image signals, respectively; first and second encoding sections for encoding the first and second image signals to generate first and second image data, respectively; first and second distance measuring sections for measuring a distance to the subject for each of image blocks, at the same time as the first and second imaging sections perform image capturing, to generate first and second distance information, respectively; first and second multiplexing sections for generating first and second multiplexed data on the basis of the first and second image data and the distance, respectively, by respectively multiplexing the first and second image data and first and second distance data, which are generated on the basis of the first and second distance information and indicate the distance to the subject for each of predefined pixel blocks in the first and second image data, re

Abstract: An antenna diversity system for radio reception for motor vehicles, which comprises a multi-antenna system having several antennas with antenna feed lines. There can be a diversity switching device for selection of a different reception signal, and an evaluation circuit which evaluates the reception quality of the reception signal just arriving at the receiver. This evaluation circuit is designed to bring a different reception signal in terms of diversity to the receiver if interference occurs, by switching over. This design also includes at least one phase rotation device which is disposed along at least one of the signal paths.

Abstract: It is described an open-loop transmit coil diversity scheme, intended for communication based on magnetic induction, wherein the diversity scheme automatically aligns the transmit coil (110) of a transmitter (100) with the receive coil of a receiver without relying on feedback information from the receiver to the transmitter (100). This may be achieved by having a plurality of coils (110, 120, 130) in the transmitter (100) and/or in the receiver. Each of these coils (110, 120, 130) may be oriented orthogonally with respect to the other coil(s). The optimal coil (130) may be selected by measuring the position angle of the transmitter (100) and/or the receiver by making use of at least one inclinometer (132). For radio communication on the transmitter and/or on the receiver this coil (130) is selected, whose orientation is maximally parallel with the orientation of the corresponding coil on the other side of the radio communication link.

Abstract: A system and method for determining the beam center location of an antenna, such as a global positioning system (GPS) antenna, are provided. A system for determining the beam center of an antenna may include a plurality of radio frequency (RF) probes, such as Integrated Transfer System (ITS) antenna elements, located at respective predefined positions surrounding the geometrical center of the antenna. The system may also include at least one detector configured to provide a measure of the RF power detected by each respective RF probe. The system may also include a processor configured to determine the beam center of the antenna based upon the predefined position of each RF probe and the measure of the RF power detected by each respective RF probe. A corresponding method is also provided.

Abstract: An apparatus for tracing position and direction of a target object through an RF signal includes two loop antennas and a position and direction determination part. The two loop antennas receive the RF signal transmitted from the target object and are perpendicularly coupled to each other. The position and direction determination part calculates two RF signal intensities received through the respective two loop antennas for comparison, and then determines that the target object transmitting an RF signal is placed in a center direction between the two loop antennas if the two RF signal intensities are the same, and otherwise determines that the target object is placed in a front direction of the loop antenna having a relatively higher RF signal intensity.

Abstract: Apparatus for determining the position of a selected object relative to a moving reference frame, the apparatus including at least one reference frame transceiver assembly firmly attached to the moving reference frame, at least one object transceiver assembly firmly attached to the selected object, an inertial measurement unit firmly attached to the selected object, an inertial navigation system firmly attached to the moving reference frame, and a tracking processor coupled with the object transceiver assembly, with the inertial measurement unit and with the inertial navigation system, the object transceiver assembly communicating with the reference frame transceiver assembly using magnetic fields, the inertial measurement unit producing IMU inertial measurements of motion of the selected object with respect to an inertially fixed reference frame, the inertial navigation system producing INS inertial measurements of motion of the moving reference frame with respect to the inertially fixed reference frame, the

Abstract: A system and method for tracking the position and orientation of a probe. Three at least partly overlapping planar antennas are used to transmit electromagnetic radiation simultaneously, with the radiation transmitted by each antenna having its own spectrum. A receiver inside the probe includes sensors of the three components of the transmitted field, with sensors for at least two of the three components being pairs of sensors, such as coils, on opposite sides of a common reference point. In one variant of the receiver, the coils are collinear and are wound about cores that are mounted in pairs of diametrically opposed apertures in the housing of the probe. Each member of a pair of coils that sense the same component of the transmitted field is connected to a different input of a differential amplifier. The position and orientation of the receiver relative to the antennas are determined noniteratively.

Abstract: In a phase-controlled antenna array for mobile devices, in particular designed for flying device, groups of controllable passive antenna elements are arranged in concentric circles around an active central antenna element. The arrangement of additional similar planar antenna arrays among the original antenna array is especially advantageous with regard to bundling the emission characteristic.

Abstract: A motion capture system includes a motion capture detecting device with sensor coils that are sequentially selected by a control section. Signals are communicated between respective input coils of input elements of an input device and the sensor coils by electromagnetic coupling. The signals received by each of the selected coils are detected by a detecting section. Three-dimensional coordinates and directions of each of the input elements are calculated by a control section so that the input elements become continuous, based on the detected signals by the detecting section.

Abstract: A three-dimensional modeling system. The modeling system includes an antenna and a stylus. The stylus has at least one tag that communicates with the antenna to provide position signals of the tag, allowing the stylus to trace the surface of an object into a processor. The system may include more than one antenna, each producing an electromagnetic field within which the object to be modeled is positioned. The stylus may have two tags, which will allow derivation of orientation information from the position signals. The stylus may have a pressure-sensitive tip allowing the communication between the tag and the antenna to be controlled only when the stylus is in contact with the object to be modeled. The system may also have at least one tag attached to the object to provide more accurate information as to the position and orientation of the object relative to the points traced by the stylus. The stylus may also be used to trace an outline or other two-dimensional shape.

Abstract: An arrangement for coupling external antennas (14, 15) to a communication unit (20) comprises, for example, a first filter (25) located in the unit, which filter combines at least signals of a first frequency range and signals of at least a second frequency range to be transmitted and feeds them via a common coupling (29, 26) to external antennas (14, 15), filters the received first signals to a first radio part (11) of the unit (20), and filters the received second signals to a second radio part (12) of the unit (20), and a second filter (16) in the antennas, for example, which filter combines at least the first signals and at least the second signals received and feeds them via the common coupling means (29, 26) to the unit (20), filters the first signals to the transmitted to first external antenna (14), and filters the second signals to be transmitted to a second external antenna (15).

Abstract: A system and method for tracking the position and orientation of a probe such as a catheter whose transverse inner dimension may be at most about two millimeters. Three planar antennas that at least partly overlap are used to transmit electromagnetic radiation simultaneously, with the radiation transmitted by each antenna having its own spectrum. In the case of single-frequency spectra, the antennas are provided with mechanisms for decoupling them from each other. A receiver inside the probe includes sensors of the three components of the transmitted field, with sensors for at least two of the three components being pairs of sensors, such as coils, disposed symmetrically with respect to a common reference point. In one variant of the receiver, the coils are collinear and are wound about cores that are mounted in pairs of diametrically opposed apertures in the housing of the probe.

Abstract: The invention relates to a diversity reception system for motor vehicles for digitally modulated terrestrial and/or satellite radio signals in a frequency range above 1 GHz. The system includes an antenna arrangement which supplies the reception signal to a radio receiver. The antenna arrangement is an antenna system having several individual antennas and several antenna components, and contains a controllable logic switching device. The individual antennas and the several antenna components are positioned on the vehicle so that different reception signals are available at the antenna connection point via discrete switching positions of a controllable logic switch. A reception level testing device comparatively determines the reception level contained in the data flow in the HF-channel with an HF channel bandwidth B.

Abstract: A position location system adapted for Military Operations in Urbanized Terrain (MOUT) training exercises that equips a player with a magnetic sensor for detecting a low frequency (LF) magnetic field from a plurality of stationary antennas. The distance between the player-borne sensor and a stationary antenna is proportional to the logarithm of the magnetic field intensity because the player remains within the “near field” of the stationary antenna. With scheduled transmissions from six stationary antennas, the position and angular orientation of a player bearing a three-axis magnetic field sensor may be resolved in three-dimensions to within one foot (30 cm). The LF magnetic field intensity is generally unaffected by structural obstructions or multipath distortion.

Abstract: A vehicle traffic sensor for detecting and monitoring vehicular targets is presented. The sensor employs a planar design resulting in a reduced profile sensor. The sensor includes a multi-layer radio frequency board with RF components on one of the sides and both isolation and planar array antennas on the opposing side. The antennas are preferably tapered planar array antennas which include one transmit antenna and one receive antenna. The sensor also includes at least one logic or signal processing board populated with components on a first side and a ground plane on a second side positioned toward the RF componentry of the RF board to form an RF shield. The boards are housed within a housing that is permeable, at least on the side through which the antenna structures propagate.

Abstract: A receiver designed to pick up an electromagnetic signal, comprises: a passive receiving antenna; a resonant circuit connected to the antenna, formed of passive components and replying, by transmitting an electric signal, to the electromagnetic signal picked up, and an electric signal processing circuit. This receiver also comprises a threshold comparator circuit defining a reference threshold and connected directly to the terminals of the resonant circuit to compare the electric signal, not amplified, with the reference threshold and to activate said processing circuit only when the amplitude of the electric signal exceeds the threshold. An object tracking system making use of the receiver described above is also disclosed.

Abstract: A system and method for tracking the position and orientation of a probe. Three at least partly overlapping planar antennas are used to transmit electromagnetic radiation simultaneously, with the radiation transmitted by each antenna having its own spectrum. A receiver inside the probe includes sensors of the three components of the transmitted field, with sensors for at least two of the three components being pairs of sensors, such as coils, on opposite sides of a common reference point. In one variant of the receiver, the coils are collinear and are wound about cores that are mounted in pairs of diametrically opposed apertures in the housing of the probe. Each member of a pair of coils that sense the same component of the transmitted field is connected to a different input of a differential amplifier. The position and orientation of the receiver relative to the antennas are determined noniteratively.

Abstract: A three-dimensional modeling system. The modeling system includes an antenna and a stylus. The stylus has at least one tag that communicates with the antenna to provide position signals of the tag, allowing the stylus to trace the surface of an object into a processor. The system may include more than one antenna, each producing an electromagnetic field within which the object to be modeled is positioned. The stylus may have two tags, which will allow derivation of orientation information from the position signals. The stylus may have a pressure-sensitive tip allowing the communication between the tag and the antenna to be controlled only when the stylus is in contact with the object to be modeled. The system may also have at least one tag attached to the object to provide more accurate information as to the position and orientation of the object relative to the points traced by the stylus. The stylus may also be used to trace an outline or other two-dimensional shape.

Abstract: A method for determining the position and orientation of an object with respect to a reference frame, made up of providing the object with three independent transmitters of electromagnetic radiation, providing three independent receivers of the electromagnetic radiation, each of the receivers having a fixed position in the reference frame, transmitting the electromagnetic radiation, using the transmitters, a first of the transmitters transmitting the electromagnetic radiation including at least a first frequency, a second of the transmitters transmitting the electromagnetic radiation including at least a second frequency different from the first frequency, and a third of the transmitters transmitting the electromagnetic radiation including at least a third frequency different from the first frequency, receiving signals corresponding to the electromagnetic radiation, at all three of the receivers, at a plurality of times, each of the signals including components of at least one of the three frequencies, for ea

Abstract: A method for tracking an object using energy fields, in the presence of interference due to introduction of an article responsive to the fields, in the vicinity of the object. One or more desired energy fields are produced in the vicinity of the object, and a characteristic of energy fields induced due to introduction of the article is determined. Signals are generated responsive to the energy fields at a plurality of locations of the object after introduction of the article. Spatial coordinates of the object are determined, responsive to the generated signals and the determined characteristic.

Abstract: A surface wave directional detection system for determining the direction in which an electromagnetic wave propagating along a metallic surface is travelling includes a first loop probe and a second loop probe positioned in close proximity to the metallic surface so that the electromagnetic wave induces a signal in each of the loop probes. The two loop probes are separated by a quarter wavelength so that the two signals induced in the probes are out of phase. The first and second loop probes are connected by equal length transmission lines to a quadrature hybrid which generates two output signals that vary in magnitude in correspondence with the direction of travel of the electromagnetic surface wave. The two output signals from the quadrature hybrid are provided to RF detectors, which generate output voltage signals that vary in proportion to the magnitude of the output signals from the quadrature hybrid.

Abstract: Systems and associated methods for tracking and/or guiding an underground boring tool are disclosed. Each system or arrangement uses one or more detectors to measure the intensity of an electromagnetic field which is transmitted from an underground boring tool. The measured intensities may then be used to determine the location of the boring tool. In a dead reckoning embodiment of the invention, one detector may be employed while, in a position determination embodiment, two or more detectors may be employed. In any embodiment, physically measurable parameters may be used in addition to measured magnetic intensities. A highly advantageous mapping tool instrument and a cubic antenna are disclosed. The former for use in the position determination embodiment and the latter for use in any magnetic field detector employed herein.

Abstract: This disclosure deals with processing radio-frequency navigation signals, particularly Loran-C signals, from crossed loop antennas (H-field antennas) by shifting the signal phase from two loops to be in quadrature with respect to each other and adding them together to achieve omnidirectivity of the antenna pattern during the acquisition mode; using the stronger signal of the two during the cycle selection mode to determine the polarity of the received signals; and calculating the relative bearing angles on transmitting stations to determine, with measured bearing, the orientation of the loop antenna with respect to these stations.

Abstract: An arrangement for identifying a movable object includes a transponder disposed on the movable object and including an electrical memory that can be read out in a wireless manner by an electrical interrogating device which is disposes in proximity of the object. A sensor arrangement is disposed on the object and electrically linked to the transponder for writing a read-out-capable status information into the memory in response to irregular or unauthorized use of the object.

Abstract: A method and apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame includes providing a source having a plurality of field-generating elements, wherein the field-generating elements generate electromagnetic fields and have spatially independent components defining a source reference coordinate frame. A driver applies signals to the source to generate a plurality of electromagnetic fields which are distinguishable from one another and a remote sensor has a plurality of field-sensing elements which sense each of the generated electromagnetic fields. A processor processes the output of the sensor in a remote object position and orientation relative to the source reference coordinate frame. At least one of the field-generating elements of the source has at least one electrically conductive sheet and a planar coil including a plurality of coplanar concentric rings above the conductive sheet.

Abstract: Position and orientation of receiving antennae with respect to magnetic field transmitting antennae are determined. The transmitter consists of two or more antenna whose dimensions are large compared to the distance to the receiver. The receiver consists of two or more antenna that are sensitive to the type of signal transmitted. A computer is used to control the transmitting and receiving elements and to convert the received signals into position and orientation.

Abstract: An electronic device for multiplexing several loads to the terminals of a source of alternating electrical energy. The source(4) of alternating electrical energy is coupled by electromagnetic flux to the loads by using primary excitation windings 71, 81 and 91 connect to the terminals of the source (4) of alternating electrical energy and secondary windings respectively corresponding to the number of loads. The secondary windings are at least partially coupled to the primary winding and are each connected to the terminals of a load. The coupling is inhibited by auxiliary winding 73 which are each totally coupled with the secondary winding 72. The inhibition function is controlled in order to inhibit all the magnetic couplings except for one and this particular one changes as a function of the respective load to be coupled to the source 4 of alternating electrical energy.

Abstract: A method of measuring the position and orientation of an object is disclosed in conjunction with an apparatus to achieve this method. The method and apparatus reduce the metal effects caused by metal objects which are in close proximity to a magnetic field generator. The metal effects are reduced by utilizing a magnetic field generator which creates a rotating magnetic field vector and then measuring the time required for that magnetic field vector to travel between a known reference point and the sensor whose position is being measured. By keeping the frequency of the rotating magnetic field vector constant and measuring the time required for this magnetic field vector to travel the previously mentioned distance, an angle between a reference axis and a vector directed toward the sensor can be determined. Once appropriate angles are measured, calculations can be undergone to determine the position of the sensor.

Abstract: An antenna configuration system for determining the bearing angle of a radio frequency signal includes a plurality of loop antennas and at least one sense antenna. Through the utilization of combining networks with the loop antennas, in-phase and out-of-phase output signals are summed with the signal from the one sense antenna. The summed signal is sent to an adaptive processing system to allow for the determination the bearing angle of the radio frequency signal.

Abstract: A method for determining a direction of arrival of an electromagnetic wave comprises the steps of: measuring sets of electric and magnetic components of an electromagnetic wave as sensed from a lumped antenna structure; finding a cross product for each measured set of electric and magnetic components so as to derive an orthogonal vector value therefrom; deriving the Castesian components for each direction vector value so determined; averaging like component vectors for each measured electric and magnetic vector component set over a plurality of measurements; and deriving a direction vector from the averaged vector values.

Abstract: A method and apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame includes a source having a plurality of field-generating elements for generating electromagnetic fields, a drive for applying, to the generator element, signals that generate a plurality of electromagnetic fields that are distinguishable from one another, a remote sensor having a plurality of field-sensing elements for sensing the fields generated by the source, and a processor for processing the outputs of the sensing elements into remote object position and orientation relative to the source reference coordinate frame. The processor compensates the position and orientation values as a function of displacement of either the field-generating elements from a common center, or the field-sensing elements from a common center, or both.

Abstract: The apparatus is an antenna system for autoadaptive direction and polarization filtering of radio waves traveling through an HF ionospheric channel and generating an output signal for coupling to a receiver. First and second crossed loop antenna elements having first and second output terminals, respectively, are disposed around a common axis. A filar antenna element has a longitudinal axis along the common axis. The filar antenna element has a first end terminal situated at the same phase center as the first and second output terminals. A multiplier circuit multiplies each value output from the first and second output terminals and the first end terminal by a corresponding complex weighting coefficient. The complex weighting coefficients are adjustable as a function of variations of polarization of a radio wave, and azimuthal and site arrival directions of the radio wave.

Abstract: An assembly is disclosed herein for locating an underground object that is transmitting a relatively low frequency signal electromagentic field. Means are provided for scanning the earth's surface and homing in on the point where the magnetic field is strongest, and at that point, calculating the depth of the object based on the strength of the magnetic field.

Abstract: A method and apparatus is disclosed for accurately determining the spatial orientation of planar and linear features expressed along the exterior surface of a core sample. The core sample is positioned in a plurality of sequentially generated orthogonal electromagnetic fields. The core sample is retained by a device which allows complete rotation of the core sample about a predetermined axis while positioned in the electromagnetic fields. A stylus containing an antenna for detecting the electromagnetic fields is used to trace surficial features along the core exterior while simultaneously detecting components of the generated electromagnetic fields. The stylus provides an output to an analyzing device which calculates the coordinates of points along the core features. The coordinates are passed to a computer which has also been monitoring the rotation angle of the core.

Abstract: A navigation method for independently determining direction and for determining course for aircraft with low quality gyros and an external, calibrated magnetic course sensor. The method, which functions in the event of failure of the magnetic course sensor, is based upon the concept of determining, from the magnetic course last determined prior to failure as corrected by the local declination, and the true course as determined by the quotient of the two gyro horizontal axes distorted by the gyro drift, a "synthetic magnetic course" for course support.

Abstract: A method and apparatus is provided for determining remote object orientation and position with an electromagnetic coupling. A plurality of radiating antennas are provided for radiating electromagnetic energy. Each of the radiating antennas have independent components for defining a source reference coordinate frame. A transmitter is provided for applying electrical signals to the radiating antennas for generating a plurality of electromagnetic fields. The signals are multiplexed so that the fields are distinguishable from one another. A plurality of receiving antennas are disposed on a remote object for receiving the transmitted electromagnetic fields. The receiving antennas have a plurality of independent components for detecting the transmitted electromagnetic fields and defining a sensor reference coordinate frame.

Abstract: A method and apparatus is provided for determining remote object orientation and position with an electromagnetic coupling. A plurality of radiating antennas are provided for radiating electromagnetic energy. Each of the radiating antennas have independent components for defining a source reference coordinate frame. A transmitter is provided for applying electrical signals to the radiating antennas for generating a plurality of electromagnetic fields. The signals are multiplexed so that the fields are distinguishable from one another. A plurality of receiving antennas are disposed on a remote object for receiving the transmitted electromagnetic fields. The receiving antennas have a plurality of independent components for detecting the transmitted electromagnetic fields and defining a sensor reference coordinate frame.

Abstract: An electromagnetic communications and switching system provides for line-of-sight remote selection and actuation of a wide variety of apparatus. The system has a plurality of radiating antennas having independent components defining a reference coordinate frame. A transmitter is provided for applying electrical signals to the antennas which generate a plurality of radio frequency electromagnetic fields. The signals are multiplexed so that the electromagnetic fields are distinguishable from one another. An array of control positions is provided that is fixed with respect to the reference coordinate frame. A plurality of receiving antennas are provided which are adapted for mounting on the head of an operator. The receiving antennas are provided with independent components for detecting and measuring the components of the electromagnetic fields. A sight couples the eyes of the operator and the array of control positions.

Abstract: A battery powered radio transmitter of a cross-sectional diameter substantially equal to the cross-sectional diameter of an arrow shaft is positioned in series between the head and nock of a metallic hunting arrow. The transmitter section of the shaft is light in weight so as not to affect the normal flight characteristics of the arrow. The shaft portion between the transmitter and the nock acts as the antenna for the transmitter. A switch is provided for operation of the transmitter. A portable directional radio receiver of the same frequency as the transmitter is utilized by the hunter to track the spent arrow.