Abstract: A satellite provides communication between user terminals (UTs) and ground stations that connect to other networks, such as the Internet. To establish initial contact with a satellite, a UT searches for a satellite's beacon using a phased array or other steerable antenna with a directional receive pattern. The UT retrieves a sky coverage map and stored satellite ephemeris data. The sky coverage map defines discrete areas of the entire sky, with each area based on satellite beacon coverage areas, receive beamwidth of the UT receive antenna, and receive antenna horizon limits. Based on a geolocation of the UT, time, and the ephemeris data, a predicted area in the sky of the satellite is determined. Candidate areas of the sky coverage map are determined that overlap the predicted area, and the receive antenna is directed to search the candidate areas for the satellite beacon.

Abstract: A method for determining the position and orientation of a vehicle, this method including measuring, with a magnetometer, a raw-measurement vector; obtaining a reference vector encoding, in a terrestrial reference frame, the amplitude and the direction of the geomagnetic field, the components of the reference vector being obtained from a pre-recorded model of the geomagnetic field and not measured by the magnetometer; then only if the margin of error in an estimate of the orientation of the vehicle is below a predetermined threshold, updating the pre-recorded data from which scale and offset coefficients used for correcting the raw measurement from the magnetometer are obtained, this update being performed using the raw vector, the reference vector and the new estimate of the orientation of the vehicle.

Abstract: Disclosed herein are systems comprising sensor devices that may be affixed to a patient and used to perform clinical measurements such as measurements for calculating a BASMI score. A first sensor device is configured to be successively attached to each of a wrist carrier, an ankle carrier, and a headset carrier. The carriers are attached to, or positioned next to, the relevant portion of the patient's body in order to perform particular measurements relating to generating a BASMI score. As the patient performs the routine of motions associated with a particular BASMI measurement, the sensor device records the measurements and communicates the measurements to a user computing device. A second sensor device is configured to be applied to the patient's torso and an additional measurement of patient flexibility taken and communicated to the user computing device. The user computing device generates a BASMI score from the recorded measurements.

Abstract: A magnetometer unit which may be incorporated in an electronic device receives first magnetic response data from a first magnetic sensor and second magnetic response data from a second magnetic sensor displaced from the first magnetic sensor. The magnetometer unit generates a composite response surface representation from the first magnetic response data and the second magnetic response data, and stores the composite response surface representation in a non-transitory memory.

Abstract: A method of magnetic sensor calibration for aircraft comprises obtaining attitude data, heading angle data, position data, and date information; inputting the position data and date into an earth magnetic field (EMF) model and into an EMF model correction map; inputting the attitude and heading angle data into a NOLL to body frame transformation module; outputting an EMF model vector from the EMF model; outputting an EMF correction vector from the EMF model correction map; compensating the EMF model vector with the EMF correction vector to produce a corrected EMF model vector; inputting the corrected EMF model vector into the transformation module; inputting magnetic field measurements data into a calibration processing unit; inputting true earth magnetic field data from the transformation module into the processing unit; computing compensation coefficients in the processing unit based on the magnetic field measurements and the true earth magnetic field; and storing the compensation coefficients.

Abstract: A recreational or outdoor mirrored compass is comprised of a base member, a hinged cover with a mirror and a sighting window for sighting a land mark, and a vial assembly pivotally coupled to said base member. The vial assembly comprises a vial, a magnetized indicator member pivotally journaled in the vial and an azimuth ring. At least parts of the inner sides of the sighting window are tapered in the line of sight.

Abstract: Systems and methods for providing aircraft heading information are provided. In one embodiment, an attitude heading reference device comprises: at least one interface for receiving heading information from one or more IRUs; at least one set of gyroscopes and accelerometers; a memory device for storing data representing heading information received via the at least one interface; and a heading calculator coupled to the at least one interface, the at least one set of gyroscopes and accelerometers, and the memory device. The heading calculator generating a heading output signal based on heading information when reliable heading information is received over the at least one interface; the heading calculator generating the heading output signal based on data from the memory device regarding previously reliable heading information and an output of the at least one set of gyroscopes and accelerometers when reliable heading information is not received over the at least one interface.

Abstract: Disclosed is a clinocompass for measuring a strike and a dip on an irregular geological outcrop and a method of measuring the strike and the dip by using the same. Since the level meter of the clinometer is supported by providing a support force and a fixing force on an irregular geological outcrop having no exposed flat plane, the clinocompass serves as a supporting member or a fixing member for the measurement of the strike and the dip on an irregular geological outcrop having no exposed flat plane. Accordingly, the clinocompass has a structure to measure the strike and the dip suitable for the geological structure and the orientation of the outcrop having no exposed flat plane, so that the strike and the dip are usefully measured.

Abstract: A multifunction measuring device includes: an orientation compass and an inclinometer mounted in a mounting seat and disposed in a housing so that the orientation compass and the inclinometer are respectively exposed through front and rear openings in the housing; a first magnification member disposed in the housing, connected movably to a connecting seat fixed in the housing, and including a first magnifying lens aligned with a first viewing hole in the housing; and a second magnification member connected movably to the housing, and including a second magnifying lens aligned with a second viewing hole in the housing.

Abstract: Systems and methods for providing aircraft heading information are provided. In one embodiment, an attitude heading reference device comprises: at least one interface for receiving heading information from one or more IRUs; at least one set of gyroscopes and accelerometers; a memory device for storing data representing heading information received via the at least one interface; and a heading calculator coupled to the at least one interface, the at least one set of gyroscopes and accelerometers, and the memory device. The heading calculator generating a heading output signal based on heading information when reliable heading information is received over the at least one interface; the heading calculator generating the heading output signal based on data from the memory device regarding previously reliable heading information and an output of the at least one set of gyroscopes and accelerometers when reliable heading information is not received over the at least one interface.

Abstract: A multifunction measuring device includes: an orientation compass and an inclinometer mounted in a mounting seat and disposed in a housing so that the orientation compass and the inclinometer are respectively exposed through front and rear openings in the housing; a first magnification member disposed in the housing, connected movably to a connecting seat fixed in the housing, and including a first magnifying lens aligned with a first viewing hole in the housing; and a second magnification member connected movably to the housing, and including a second magnifying lens aligned with a second viewing hole in the housing.

Abstract: The instant invention utilizes two, optionally orthogonal and optionally slightly tilted, horizontal magnetic sensors and, optionally, a 2 or 3 axis accelerometer or inclinometer to calculate a pitch, roll and tilt compensated heading. A vertical, Z, component is relatively constant compared to X and Y components, the Z component can be abstracted from the X and Y sensor when pitch and roll is applied based on Z offset measured with X or Y sensor at high tilt angles. Additional sensors tilted at various ? degrees can be added with a different angle ? to X sensors when additional horizontal and magnetic coverage is desirable.

Abstract: An alignment device and method for aligning an antenna with a satellite. The device includes a grooved cylindrical sleeve inserted into a ridged cylindrical sleeve, a raised azimuth indicator ring and a magnetic or digital compass mounted upon the grooved cylindrical sleeve, and a bubble level mounted on a capped cylindrical sleeve that fits over the grooved cylindrical sleeve. A known value of optimal azimuth alignment is offset from the North Magnetic Pole so that a reference and alignment mark may be placed on the antenna mounting pole. This alignment device and method eliminate the need for two technicians and eliminate the need for a signal strength measuring device.

Abstract: A method for controlling an electronic compass includes receiving raw magnetic field data into a calibration module and determining a calibration output based upon the raw magnetic field data. The raw magnetic field data is also received into a compass heading module for determining compass heading outputs based upon the raw magnetic field data. The calibration module filters the raw magnetic field data and validates the calibration outputs independently from output data filtering and results validation in the compass heading module.

Abstract: A satellite line of site alignment device for the installation of all satellite dish antenna. The alignment device provides a hand held orientation and angular inclination determination for properly positioning a satellite receiving dish with a known geosynchronous orbiting satellite transmitter. Receiving dish location longitude and latitude, satellite to be aligned to, and true north and level orientation are so configured to provide visually for siting through an eye piece for line of site object avoidance determination prior to satellite dish antenna installation.

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: A method for characterizing distortions in the earth's magnetic field caused by a vehicle having a magnetometer affixed therein is described. The method includes repeatedly measuring the distorted magnetic field utilizing the magnetometer and obtaining a three-dimensional orientation of the vehicle axes with respect to the earth at a time of each magnetometer measurement. The method also includes receiving undistorted earth magnetic field data for the vicinity of the vehicle relative to the earth at the time of each magnetometer measurement and characterizing distortions caused by one or more of the vehicle and magnetometer errors utilizing the magnetic field measurements, the orientations of the vehicle, and the undistorted earth magnetic field data.

Abstract: A compass adapted to measure direction and dip values with or without the assistance of the earth's magnetic field. A laser pointer module and a magnetic needle module are interchangeably arranged in a body having an attached reference angle plate appropriately set to measure horizontal and vertical angles. The compass is especially useful in underground mines or other locations having magnetic anomalies where conventional magnetic compasses are rendered useless. Both embodiments are capable of taking readings when the compass is set in an upright or upside-down position.

Abstract: A low profile compass of the type including a transparent base member and fluid-filled vial contains a directional indicator in the vial in the form of a circle which is alignable with another circle imprinted on the vial. A hinged cover assembly can be detented to selected positions and includes a mirrored sight line for direct line sighting, and a lower protective cover or shoe for the base of the compass also serves as a receptacle for instruction sheets and scales for use in taking directional readings as well as for orientation alignment on a topographic map and inclinometer readings.

Abstract: An electronic compass comprises a saturable core sensor (2) with a core (3) made of ferromagnetic material surrounded by an electric winding (3′), a first couple of electric windings (4, 5) around the sensor (2) having reciprocally orthogonal turns, a second couple of electric windings (8, 9) around said first couple (4, 5) having reciprocally orthogonal turns. The gap between the winding (3′) and the first couple of windings (4, 5) and between the first couple of windings (4, 5) and the second couple of windings (8, 9) is filled with a material having a low thermal expansion coefficient, preferably epoxy fibreglass reinforced plastic, supporting the windings of said first (4, 5) and second (8, 9) couple of windings. It is also provided an electronic control circuit (20, 21, 22).

Abstract: The invention provides a novelty item comprising a compass-like device having a housing and a magnetized compass needle suspended therein, the device further comprising a compass face positioned above the needle and hiding same from view, wherein the magnetized needle is rigidly attached, via a linking means, to a non-magnetized pointer positioned in a plane parallel to the plane of the magnetized compass needle above the compass face and angularly displaced from the magnetized compass needle, whereby the non-magnetized pointer always points to a direction other than North.

Abstract: A low profile compass of the type including a transparent base member and fluid-filled vial contains a directional indicator in the vial in the form of a circle which is alignable with another circle imprinted on the vial. A hinged cover assembly can be detented to selected positions and includes a mirrored sight line for direct line sighting, and a lower protective cover or shoe for the base of the compass also serves as a receptacle for instruction sheets and scales for use in taking directional readings as well as for orientation alignment on a topographic map and inclinometer readings.

Abstract: An compass having an electronic magnetic field sensor and an analog directional display is disclosed wherein a signal from the field sensor proportional to one component of the earth's magnetic field is alternated in polarity and integrated to produce a triangular waveform the frequency of which is proportional to the strength of that field component and wherein a triangular waveform having a frequency proportional to the second component of the earth's magnetic field is produced in the same manner. These values are used by a microcontroller to control an air-core gauge such that a disk with reference markings attached to the gauge remains positioned with one of the reference markings facing either magnetic or true north. A resistor ladder network is also connected in parallel to the inputs of the integrators and controlled by the microprocessor through a shift register in order keep the integrators out of saturation.

Abstract: The present invention provides a compass comprising an at-least-partially-transparent housing having a top and a bottom, a vertically orientated, conical pivot bearing, and a magnetic detection means which is mounted on the vertically-oriented conical pivot bearing. The magnetic detection means thereby is capable of rotating in a substantially-horizontal plane. The magnetic field detection means is provided with a radially-extending, tilt-compensating, indicator device. The indicator device has at least one spacer element which is spaced from the magnetic field detection means, the spacer element projecting from the indicator device and being directed towards one of a top of the housing of the compass and a bottom of the housing of the compass.

Abstract: A map is provided for indicating the direction of a fixed point (S), such as a sub-satellite point, from any point (P) within a specified area which is a substantial fraction of the earth's surface. The map projection is such that the actual direction to the fixed point (S) is the same as the direction shown on the map, when the map is aligned with a reference direction such as magnetic north. Optionally, the distance to the fixed point on the map represents the elevation of the satellite. Apparatus for using the map includes a holder (10) for the map and for a magnetic compass (18). A scale (22) which rotates about the fixed point on the map has a marker (32) which is positioned over the user's location on the map. The azimuthal direction of the satellite is indicated by an arrow (28) on the scale, while the elevation of the satellite is read off the scale by means of a pointer (34) located on the fixed point on the map.

Abstract: A method for converting distorted compass data values into corrected data values which employs linear transforms. A linear transform is formulated and programmed into the read only memory of the microcomputer of the electronic compass system. The microcomputer uses the linear transform to transform compass data readings distorted by ferrous metals in the environment of the vehicle into corrected data readings and then uses the corrected data readings to compute headings.

Abstract: The arrangement (42) according to the invention is formed by a watch comprising a dial (8) on which is shown a map (14) centered on a given geographic location, Mecca in particular. The arrangement (42) comprises a device (48) for indicating the direction of the terrestrial magnetic north and a device (16) enabling the angular positioning of the map in the general plane of the arrangement (42) corresponding to the plane of the dial (8). The different geographic regions shown on the map (14) are graphically arranged so that any point whatsoever of the contours of such regions substantially shows an angular spread (.OMEGA.), relative to a center of reference (22) corresponding to the above-mentioned given geographic location and to a reference direction (24) equal to the magnetic azimuth of the great circle passing through said point and the reference point (22) augmented by 180.degree..

Abstract: A magnetic compass comprising an arrangement to displace a correcting marker to create a compass correcting coefficient equal to the sum of the variation and the deviation errors effecting the compass so as to counteract the compass error, and to indicate the true course. The correcting marker becomes the steering reference and a vessel is steered so that the correcting marker is aligned with the true course to be steered by the vessel. Repeaters fed from this compass, which repeaters are fed by the hunting between the compass card and the displaceable correcting marker, indicate the true course as well as true bearings. The displacement of the correcting marker can be controlled from a computer programme which displaces the correcting marker in dependence upon the effecting variation and deviation. Thus the magnetic compass shows true course and the repeaters show true course and true bearings automatically.

Abstract: A navigation device is disclosed, having a lens across an opening at one end of a case, and a compass across an opening at the opposite end of the case. A transparency holder is positioned between the lens and the compass, adapted to receive a map transparency with magnetic north thereon aligning with a north marking on the body of the compass, at a distance from the lens approximating the focal length of the lens. A first grid wheel is provided between the transparency holder and the compass, having a transparent or translucent central area inscribed with parallel grid lines and at least one first directional arrow aligned parallel to the grid lines, the grid wheel being in close proximity to the transparency holder such that it is also at a distance from the lens approximating the focal length of the lens.

Abstract: A level includes a compass member fixedly mounted within the level, the level having spirit levels positioned on opposed sides of the compass, and the compass having a rotatable ring arranged to provide for angular deflection relative to a predetermined orientation.

Abstract: An electronic compass has a display including a reference pointer that indicates a reference heading stored in response to an input signal. The reference heading is the current heading at the time of the input signal, and the reference pointer in the display is updated as the orientation of the compass changes.

Abstract: A transparency holder for use in a navigation device is disclosed. The transparency holder is positioned between a lens and a compass, and is adapted to receive a map transparency in one correct orientation only. The one orientation only feature is achieved by providing certain asymmetric features, such as off-center notches which engage complementary features in the navigation device. In the preferred embodiment, the transparency holder has integral upper and lower halves hinged together by a living hinge and sandwiching the map transparency therebetween.

Abstract: A combination of a compass and a connective arrangement for facilitating connection of the compass to a firearm or other portable object. The connective arrangement includes a one or two part elongated and hollow sleeve having an interior opening therein opening outwardly at opposite first and second ends. A housing containing the compass works is received in the first end of the sleeve. The interior opening at the second end of the sleeve has an internal thread threadedly secured to an externally threaded screw to thereby facilitate the connection of the compass works containing housing to the firearm or other portable object.

Abstract: A combination of a compass and a connecting arrangement. The compass includes a compass housing having a base wall, a circular wall connected to and upstanding from the base wall and a transparent window connected to the circular wall to define a sealed chamber in which is located the compass works. The compass housing has a radially outwardly extending flange thereon which is greater in dimension than the outer diameter of the circular wall. The connecting arrangement includes a strap for securing the compass housing to an archer's bow. The strap includes an elongated, uniformly thin strip of material having oppositely facing surfaces. The strap has a centrally disposed, circular-shaped first hole therethrough, the diameter of the circular-shaped hole being less than the diameter of the aforesaid flange. The compass housing is received in the circular-shaped first hole, the flange abutting the second surface on the strap.

Abstract: A navigation device for personal use includes a face mask with a transparent window for binocular vision when the device is worn by the user. The face mask has a directional indicator attachement with a multiplicity of symbols to identify the directional orientation of the mask. The directional indicator is attached at a stable location and distance for continuous availability of direct binocular viewing.

Abstract: A solid-state heading sensor is comprised by a three-axis Hall effect magnetometer and a three-axis accelerometer. The magnetometer is comprised by a cube-like structure (10) of non-magnetic material on each of three orthogonally related faces of which is located a respective Hall effect device (11, 12, 13), for example of GaAs. The three-axis accelerometer may be comprised by a three-axis module (15) disposed in a recess in the cube-like structure, or by three separate accelerometer structures (23, 24, 25), for example planar etched silicon accelerometers, each disposed on a respective one of the orthogonally related faces adjacent the Hall effect device (20, 21, 22) thereon.

Abstract: An alignment gage for accurately positioning the azimuth and elevation angles of a fixed receiving dish antenna. The alignment gage is mounted to the dish and includes a gravity actuated pendulum cooperating with an arcuate scale for setting the elevational angle. A magnetic compass having a graduated scale is used to set the azimuth angle of the antenna. In one embodiment, the compass surmounts the pendulum so as to remain in a horizontal position. The gage is particularly adapted for use by unskilled persons for use in installing home dish antennas.

Abstract: An instrument for measuring positions and displacements of portions of a human body, comprising a base plate and a belt or suction cup for detachably securing the base plate to a portion of a human body. A bifurcated holder is mounted on the base plate for rotation about a first axis, the bifurcated holder having a pair of arms, and a housing is pivotally carried between these arms for swinging movement about a second axis perpendicular to the first axis. A dip circle and a north-south-seeking compass are carried by this housing, the dip circle and compass being mounted on the housing for pivotal movement about a common third axis perpendicular to the second axis. The base plate has a scale thereon, and there is an indicator on the holder for indicating on the scale the degree of rotation of the holder relative to the base plate.

Abstract: Apparatuses and processes for detecting misalignments between various portions of a deformable body, such as an aircraft, are disclosed. Orientation detection devices, such as potentiometric vertical indicators and gyros, are provided at a master module disposed at a predetermined location on the structure and in a remote module located at a predetermined portion of the structure remote from the reference location. The orientation of the remote portion of the structure, as determined from the remote module is compared to the orientation of the master module to thereby determine the orientation of the remote portion of the structure relative to a fixed reference. The orientation detection devices are secured to the various locations through the use of a standardized track and base assembly, whereby virtually all components of the master and remote modules are interchangeable. The remote module may be disposed on a trammel point assembly wherein the orientation of a predetermined surface may be determined.

Abstract: A cylindrical compass gimballing and data readout system permitting 360.degree. rotation about both yaw and roll axes includes a cylindrical compass housing flooded with semiconductive fluid to permit transmission of a digitally multiplexed signal from a remote reading compass to a processing unit in which the fluid is interposed between spaced-apart plates located along and perpendicular to the roll axis of the compass. This permits electrical connection to and from the compass, and permits not only 360.degree. rotation about the yaw axis for compass heading readout, but also 360.degree. rotation of the compass about the roll axis to permit use in seismic streamers.

Abstract: A plumb measuring device fabricated from a plurality of detachable modular assemblies includes a first assembly provided with an alignment bar, a scale plate pivotally mounted to the bar for determining the plumbness of a vertical surface, a bubble level attached to the scale plate to determine the level line of a vertical surface, indicia marked on the bar for reading the scale. A second scale plate is pivotally mounted just above the first scale plate for determining the degree of tolerance from plumb. A second modular assembly comprising interchangeable alignment bar extension members to be attached to either end of the bar for increasing the length of the measuring device. A third modular assembly comprising spacer means for detachable connection with the first or second assemblies to act as stand-offs to bridge distorted intermediate regions on a vertical surface. A compass is provided for attachment to the top of the first or second assembly for determining whether a driven pile has been rotated.

Abstract: A spherical compass having a gravity operated support for automatically positioning its double axis gimbal system into a horizontal plane for selective mounting of the compass with its outer athwartships gimbal system axis mounted horizontally and its fore and aft compass mounting plane oriented at any angle between the horizontal and vertical. The support comprises a gimbal support unit mounted within the pair of hemispherical compass bowls for limited vertical movement from a normal lowered position in frictional damping contact with the inner surface of the lower of the hemispherical bowls to a raised position of reduced frictional contact to permit gravity adjustment of the gimbal system fore and aft axis and the fore and aft lubber lines and compass card into a horizontal plane.

Abstract: In a magnetic compass compensation system suitable for use within a ferrous land vehicle, a secondary magnetic sensor senses, the total magnetic field as components along a three axis system drawn vertical, lateral and transverse to the ferrous vehicle. Compensation signals corresponding to the permanent and induced magnetic fields of the vehicle are isolated from the total magnetic field. The compensation signals are applied to compensation coils surrounding a primary magnetic sensor for providing an output equivalent to the horizontal components of the earth's undisturbed magnetic field.

Abstract: Apparatus for determining the positional coordinates of a moving object including a plurality of magnetic field vector detecting devices, an inclination detecting device for detecting inclination of the magnetic field vector detecting devices, a distance detecting device for detecting the distance that the moving object has travelled, and arithmetic means which receives outputs from the magnetic field vector detecting devices as well as from the inclination detecting device, calculates the horizontal component force vector of the geomagnetic field by using the outputs from the magnetic field vector detecting devices and from the inclination detecting device, further calculates the vector in the progress direction of the moving object by referring to the horizontal component force vector, and integrates the product of the vector in the progress direction and the output from the distance detecting device, whereby the positional coordinates are obtained as the output of the arithmetic means, and the coordinates

Abstract: A terrestrial magnetism responsive device adapted to be worked using a north or south seeking magnet in both north and south headings, the device including a housing having a north or south seeking magnet therein. The magnet is suspended adjacent one pole by a sensitive spring to permit the magnet to be movable horizontally, when released, from a north pointing position or a south pointing position. Secured and balanced on the seeking or free end of the magnet is a soft iron rod, generally at ninety degrees to the magnet and having substantially the same diameter as the magnet. The rod is balanced along with the magnet so that the magnet and rod together will move horizontally. The housing is rotatable on a plate by which it is held and during operation is fixed on the plate to be moved horizontally in the direction of an area to be explored.

Abstract: A terrestrial magnetism responsive device adapted to use a north or south seeking magnet in both north and south headings, the device including a housing having a north or south seeking magnet therein, the magnet being suspended adjacent one pole by a sensitive spring to permit the magnet to be movable horizontally, when released, from a north pointing position or a south pointing position. The method includes the releasing of a north or south seeking magnet in the housing so that it is free to move easterly or westerly on the spring, moving the housing over the areas to be explored, and recording the east/west diversions of the magnet and the exact locations of the diversions.

Abstract: A gyroscopic device of the type having a short-circuited rotor winding or conductor so shaped so as to produce axial and radial flux components when rotated in the earth's magnetic field is coupled to a coaxial sensing coil coaxial which gyroscopically stabilized thereby, signals induced in the sensing coil due to the axial flux component of the rotor is used to derive magnetic heading information and there is provided at least one further coil on the supporting body and inductively linked to the sensing coil and rotor such that when the sensing coil is gyroscopically stabilized by the rotor, the coil supported on the supporting body in relation to the gyroscopically stabilized sensing coil is such that any changes in angular orientation of the supporting body relative to the gyroscopically stabilized sensing coil introduces changes in the signal voltages induced in the coils.

Abstract: An inclination responsive device including a coil energized to produce a magnetic field extending along a normally vertical axis of the device, and a flux gate assembly adapted to respond to a horizontal component of that field upon tilting movement of the axis to an inclined non-vertical position, and to thereby produce an output which varies in response to changes in inclination. The flux gate assembly is desirably also responsive to the earth's magnetic field or another ambient field to also produce an output representing directional orientation of the device with respect to the ambient field.

Abstract: A magnetic compass in which the compass magnet is an electromagnet energized only when in a horizontal disposition to provide a correct heading indication without error due to tilting of the compass magnet.

Abstract: A direction finding device employs a magnetic field sensor utilizing a vibrating magnetic reed switch with adjustable magnetic bias to vary the sensitivity or dead band. By sensing magnetic North, it indicates audibly, visually or by nerve stimulus any departure from a preset course. When attached to a moving object or person it serves as a warning or guidance system.