Class / Patent application number | Description | Number of patent applications / Date published |
073382000 | GRAVITATIONAL DETERMINATION | 77 |
20080257039 | Device and Method for the Gravimetric Determination of Liquid Volumes and Analyzer System Comprising Such a Device - A device for the gravimetric volume determination of liquid volumes. The device comprises a housing ( | 10-23-2008 |
20080295594 | METHOD AND APPARATUS FOR MEASUREMENTS OF GRAVITY IN SMALL DIAMETER BOREHOLES - An apparatus for measuring gravity in a small diameter borehole comprises a pressure tube and at least one pendulum gravity sensor accommodated by the pressure tube. The gravity sensor comprises a pendulum and circuitry to monitor generally continuously the swing period and amplitude of the pendulum. | 12-04-2008 |
20090044621 | Accelerometer and Rate Sensor Package for Gravity Gradiometer Instruments - An accelerometer and rate sensor package to aid gravity gradiometers is provided. The accelerometer and rate sensor package is mounted directly on or within a gravity gradiometer instrument (GGI). Outputs from the sensors can be used to reduce unwanted noise due to angular rotational rates, angular accelerations and linear accelerations that may be coupled to the GGI. Since the sensor assembly is directly mounted on or within the GGI, the sensor assembly is coupled to the GGI and senses the acceleration and angular rates as seen by the GGI. Thus, outputs from the GGI can be corrected more effectively using the sensor assembly's outputs. | 02-19-2009 |
20090114013 | APPARATUS AND METHOD FOR IMPROVED LIGHT SOURCE AND LIGHT DETECTOR FOR GRAVIMETER - An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole. | 05-07-2009 |
20090114014 | FORCE AND ACCELERATION SENSOR USING FOUR WAVE MIXING TECHNIQUE - A sensor for measuring force, the sensor including: a light source; and a mixing medium in optical communication with the light source and exposed to the force; wherein four wave mixing of light interacting with the mixing medium provides a signal that indicates the force. | 05-07-2009 |
20090126486 | ORIENTATION INDEPENDENT GRAVITY SENSOR - An instrument for measuring gravitational acceleration, the instrument including: a plurality of accelerometers disposed about a three-dimensional structure, the plurality of accelerometers providing output used for measuring the gravitational acceleration; wherein each accelerometer in the plurality is implemented by at least one of a micro-electromechanical system (MEMS) and a nano-electromechanical system (NEMS). | 05-21-2009 |
20090235740 | Gravity Gradient Sensor - A gravimeter for detecting a gravity difference between two points is disclosed. The gravimeter comprises an interferometric arrangement wherein the length of a reference arm is dependent upon the gravity local to a first accelerometer and the length of a sample arm is dependent upon the gravity local to a second accelerometer. A pair of photodetectors that operate in complimentary fashion provide electrical signals based on a first signal conveyed by the reference arm and a second signal conveyed by the sample arm. A change in the differential gravity between the two points induces equal and opposite changes to the magnitudes of the two electrical signals. | 09-24-2009 |
20090293611 | Gravity Gradiometer - A gravity gradiometer and method for forming a pivot flexure web for a gradiometer is disclosed. The gradiometer has measurement bars | 12-03-2009 |
20090293612 | GRAVITY SENSOR AND ELECTRONIC DEVICE USING THE SAME - A gravity sensor includes a chamber, a number of receiving holes, an electrically insulative liquid, a number of pressure sensors, and a number of sealing elements. The receiving holes are defined in the inner surface of the chamber. The electrically insulative liquid is sealed within the chamber. The pressure sensors are disposed in the receiving holes respectively, and are configured for sensing the pressure that the electrically insulative liquid apply thereto. The sealing elements is configured for sealing the receiving holes respectively when the corresponding pressure sensor senses a pressure applied by the electrically insulative liquid. | 12-03-2009 |
20100071461 | MICROGRAVIMETER FOR GEOPHYSICAL PROSPECTING - An apparatus and a method for measuring the gravitational acceleration on the ground, for example adapted to geophysical explorations applied to mining, comprising a base frame ( | 03-25-2010 |
20100071462 | Gravity Gradiometer - The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass. | 03-25-2010 |
20100083753 | METHOD FOR THE ESTIMATION OF FLUIDS MOVED IN COMPARTMENTED AREAS OF THE SUBSOIL - The present invention relates to a method for estimating fluid volumes moved in compartmented areas of the subsoil, including steps which consist in effecting, in a survey field, a series of gradiometric measurement campaigns “for framing/calibrating the area” at pre-established time intervals, for each of which the relative variation ΔV | 04-08-2010 |
20100116049 | Gravimeter Launch Mechanism - A gravimeter that utilizes an electromagnetic launcher for enabling a free-fall of a test mass is disclosed. The electromagnetic launcher propels the test mass upward such that the test mass begins to free-fall once it has reached the apex of its flight. In addition, in some embodiments, the test mass comprises only non-ferromagnetic materials so that the free-fall of the test mass is unperturbed by magnetically induced influences. | 05-13-2010 |
20100147071 | Matter-Wave Gravimeter Incorporated into an Atom Chip - The general field of the invention is that of gravimeters, of the matter-wave type, allowing the measurement of the gravitational field or of an acceleration in a given direction of measurement. This type of gravimeter uses ultracold atoms to take the measurement. It necessarily comprises an atom trap ( | 06-17-2010 |
20100175472 | Gravity Survey with Relative and Absolute Gravimeters - A gravity survey is conducted by obtaining relative gravity measurements from a plurality of survey points using a relative gravimeter, obtaining absolute gravity measurements from a subset of a lesser plurality of the survey points designated as combination survey points, determining a correction factor related to any difference between the relative and absolute gravity measurements at each of the combination survey points, and correcting the relative gravity measurements made at the survey points which are not combination survey points using the correction factor. The absolute and corrected relative gravity measurements at the survey points constitute the gravity survey. | 07-15-2010 |
20100275686 | INERTIAL SENSING SYSTEM WITH A CURVED BASE AND A DIAMAGNETIC MASS - An inertial sensing system includes a diamagnetic mass, a plurality of permanent magnets positioned to form a curved base, wherein the plurality of permanent magnets are configured to provide an inhomogeneous magnetic field upon which the diamagnetic mass becomes levitated above the plurality of permanent magnets within the curved base and wherein the curved base also provides a confinement potential to substantially prevent the diamagnetic mass from exiting an interior of the curved base, and a tracking apparatus for monitoring at least one of a position and an orientation of the diamagnetic mass with respect to the curved structure. | 11-04-2010 |
20110303005 | METHOD OF DETERMINING THE DIP OF A FORMATION - A method of determining the dip or apparent dip of a section of a subterranean formation is described using the measurements of a borehole gravity meter and a dip-dependent model for the response of the gravity meter. | 12-15-2011 |
20120279296 | METHOD AND APPARATUS FOR MOTION SENSING WITH INDEPENDENT GRIP DIRECTION - A motion sensing technique. A method for motion sensing of a motion sensing apparatus include determining a gravity direction, determining an actual motion, and determining a current motion based on the determined gravity direction, the determined actual motion direction, and a previous motion direction. | 11-08-2012 |
20130031975 | GRADIOMETER - Primarily (but not exclusively) in the field of natural resources exploration, there is a requirement to measure the absolute value and variation of gravity at a given point and over an area gradient, thereby detecting the presence of sub-surface anomalies which give rise to the variation in the measured gravity value. In order to provide a portable, accurate, efficient and cost effective method for making the measurements, a gravity sensing apparatus (ABCD) can be deployed using a variety of vehicles, such as (for example, but not limited to) an aircraft or helicopter, with compensation applied by a motion sensing apparatus (EFGH) to reduce or eliminate the effects of vibration and vehicle motion and structural flexure on the gravity and gravity gradiometry data. | 02-07-2013 |
20130042680 | APPARATUS FOR MEASURING GRAVITATIONAL FORCE AND METHODS OF USING THE SAME - An apparatus for measuring gravitational force is provided having at least one optomechanical oscillator, the at least one optomechanical oscillator having an initial resonance, and a second resonance when displaced by gravitational force; and at least one photonic crystal having at least one cavity coupling optical and mechanical degrees of freedom of the oscillator. | 02-21-2013 |
20130186198 | GRAVITY AXIS DETERMINATION APPARATUS AND MOBILE TERMINAL APPARATUS USING THE SAME - A gravity axis determination apparatus which can determine the gravity direction in a short time. The apparatus is low in cost and has a simple construction. Data values of acceleration data trains in a same time zone are mutually compared and one of the three axes is determined as a gravity axis. | 07-25-2013 |
20130205894 | Interferometric Differential Free-Fall Gradiometer - The invention relates to an interferometric free-fall gravity gradiometer, comprising at least one source of coherent light L and a first retroreflector TM | 08-15-2013 |
20140007677 | ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - A device comprising a laser system ( | 01-09-2014 |
20140013841 | ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - An absolute gravimetric measurement device including, in succession, a laser system, a supporting surface of the laser system, an ultra-vacuum system, a retroreflective mirror, and a seismic attenuation system. The seismic attenuation system includes an upper plate including a hole above which the retroreflective mirror is kept suspended by at least three metallic blades including first ends constrained to a periphery of the plate and second ends above the hole in correspondence with the retroreflective mirror, the metallic blades configured to form a spring-antispring geometry for damping vibrations of the retroreflective mirror. The absolute gravimetric measurement device also includes a mechanism leveling the retroreflective mirror integral with the seismic attenuation system and a radial constraining mechanism between the retroreflective mirror and the upper plate. | 01-16-2014 |
20140026655 | Test Mass and Method for Interferometric Gravity Characteristic Measurement - A test mass used for light beam interferometric gravity characteristic measurement has a center of mass located equidistant and colinear with optical center points of two oppositely reflecting retroreflectors. Rotation of the test mass about its center of mass during freefall changes the path length of the oppositely reflected light beams by equal amounts, thereby achieving common mode cancellation of the effects of test mass rotation when the two reflected light beams are interferometrically combined. | 01-30-2014 |
20140083186 | SYSTEMS, DEVICES AND METHODS FOR BOREHOLE GRAVIMETRY - A gravimeter, a gravimeter system, and a method for measuring gravitational acceleration within a borehole are described herein. The gravimeter includes a proof mass that is constrained by springs and an optical interferometer for measuring displacement of the proof mass. The optical interferometer generates a light path from a light source to a reflective surface on the proof mass. Spatial displacement of the proof mass from a reference position to a position of gravitational equilibrium is determined by measuring a change in length of the light path. In turn, gravitational acceleration can be determined from the spatial displacement of the proof mass. A number of such gravimeters can be used in a gravimeter system to make measurements of gravitational acceleration in variety of different directions. | 03-27-2014 |
20140096606 | DETECTOR OF GRAVITATIONAL WAVES AND METHOD OF DETECTING GRAVITATIONAL WAVES - A semiconductor detector of gravitational waves of a first frequency may include an oscillator having a metal coated oscillating member over a metal coated semiconductor substrate to be subjected to a Casimir attraction force towards the semiconductor substrate. The oscillator may be configured to exert a force to counterbalance the Casimir attraction force causing the oscillating member oscillates with a main harmonic resonance frequency equal to the first frequency. A displacement sensor may be coupled to the substrate and oscillating member and configured to sense oscillations and to generate corresponding sense signals. A pass-band filter may be tuned to the main harmonic resonance frequency and configured to generate band-pass replica signals of the sense signals, and an airtight package may be configured to keep a vacuum between the oscillating member and the semiconductor substrate. An array of semiconductor detectors and a method of detecting gravitational waves are also disclosed. | 04-10-2014 |
20140102191 | PILOTING METHOD OF A LASER SYSTEM OF AN ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - A piloting method of a laser system of an absolute gravimetric measurement device by atomic interferometry particularly suitable for on-site applications and advantageously usable in the geophysical field, including: generating cooling, entrapment, manipulation, thrust, and detection bands of a plurality of atoms; cooling the plurality of atoms; entrapping the plurality of cooled atoms in a three-dimensional magneto-optical trap; releasing the plurality of atoms in free fall in an ultra-vacuum system; performing an interferometric sequence; performing a detection; wherein the releasing includes quenching the three-dimensional magneto-optical trap through the contemporaneous extinction of the bands for producing a three-dimensional magneto-optical trap and a trap magnetic field. | 04-17-2014 |
20140165720 | ESTIMATING CHANGE IN POSITION OF PRODUCTION TUBING IN A WELL - Characterizing a parameter of interest relating to a formation intersected by a borehole. Methods may include estimating the parameter using at least one gravity measurement adjusted to account for a gravity field gradient associated with a change in a frame of reference caused by removal of a reference feature from the borehole. Methods may also include taking at least one prior gravity measurement before removal of the reference feature from the borehole; taking at least one prior gravity measurement after removal of the reference feature from the borehole; estimating the change in the frame of reference based on the prior gravity measurements taken before and after removal of the reference feature; and adjusting the at least one gravity measurement using the estimated change. | 06-19-2014 |
20140190255 | ULTRA HIGH RESOLUTION GRAVITY GRADIOMETERY TECHNIQUE - A method and system provide the ability to measure relative displacement and rotation. A first light is continuously shined from a first light source that is fixed on a first entity to a first two-dimensional (2D) plate fixed on a second entity. The first direction of propagation of the first light does not change relative to the first entity. A second light is shined from a second light source that is fixed on the first entity to a second 2D plate fixed on the second entity. A second direction of propagation of the second light does not change relative to the first entity and is different from the first direction of propagation. The displacement of the lights on plates is directly monitored to determine a 3D displacement vector that represents a relative displacement between the first entity and the second entity. Thus, a three dimensional gravity gradient tensor is constructed. | 07-10-2014 |
20140260605 | Polarized Beam, Matched Coincident Beam Path, Interferometric Gradiometer Apparatus and Method - A gravity gradient is measured interferometrically from two polarized light beams having mutually different polarization planes which reflect from opposite surfaces of two freefalling test masses. The two polarized light beams project along matched coincident beam paths and divert from the coincident paths to interact with the freefalling test masses. An enhanced level of common mode rejection of adverse influences arises from traversing the coincident beam paths. | 09-18-2014 |
20140318239 | Interferometric Gravimeter Apparatus and Method - A gravity value is measured using two light beams which each reflect from both a freefall test mass and a stationary reference test mass which is inertially supported by a long period isolation device. The optical path lengths of the light beams change equally and oppositely in response to gravity and equally in response to disturbances, resulting in cancellation of the undesirable effects of the disturbances by common mode rejection and in a desirable increase in the number of gravity induced measurement fringes, when the two light beams are combined interferometrically. | 10-30-2014 |
20140338445 | METHOD OF UTILIZING MOBILE DEVICE TO DETECT EMERGENCY AND RELATED EMERGENCY DETECTING SYSTEM - A method of utilizing a mobile device to detect an emergency includes detecting whether the mobile device is carried by a user; detecting an acceleration status of the mobile device when the mobile device is determined to be carried by the user; and determining whether the user is in the emergency according to the acceleration status of the mobile device. | 11-20-2014 |
20150090028 | Atom Interferometry Device for Differential Inertial Measurement - An atom interferometer with differential inertial measurement comprises an atom source system to supply several sets of atoms intended for acceleration measurements which are made simultaneously at different respective locations. The sets of atoms are transported by a dedicated system between an initial position and the locations at which the acceleration measurements are made. The interferometer can be used to obtain highly accurate acceleration or gravity gradient measurement results. | 04-02-2015 |
20150128696 | Superconducting Acceleration Sensor Suitable For Gravitational Wave Radiation Detection - This invention detects mass and mass motion of external objects by virtue of its action as a gravimeter, gravity gradiometer, and detector of gravitational fields. This invention is for devices which function as accelerometers and gyroscopes for the bodies to which they are attached. | 05-14-2015 |
20150331142 | MATTER-WAVE GRAVIMETER WITH MICROWAVE SEPARATION AT THE MAGIC FIELD - The general field of the invention is that of matter-wave gravimeters. The gravimeter according to the invention comprises at least:
| 11-19-2015 |
20160116631 | Method for Producing an Integrated Circuit Pointed Element, and Corresponding Integrated Circuit - A method for producing an integrated circuit pointed element is disclosed. An element has a projection with a concave part directing its concavity towards the element. The element includes a first etchable material. A zone is formed around the concave part of the element. The zone includes a second material that is less rapidly etchable than the first material for a particular etchant. The first material and the second material are etched with the particular etchant to form an open crater in the concave part and thus to form a pointed region of the element. | 04-28-2016 |
20160178792 | GRADIOMETER CONFIGURATION INVARIANT TO LASER PHASE NOISE AND SENSOR ROTATIONS | 06-23-2016 |
20080236277 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 10-02-2008 |
20080257038 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 10-23-2008 |
20080282796 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 11-20-2008 |
20080302179 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-11-2008 |
20080302180 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-11-2008 |
20080307883 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-18-2008 |
20090064778 | Gravity Gradiometer System - A methods and apparatus for an improved gravity gradiometer are disclosed. | 03-12-2009 |
20100005882 | Gravity Gradiometer - The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass. | 01-14-2010 |
20100031746 | HIGH-RESOLUTION DIGITAL SEISMIC AND GRAVITY SENSOR AND METHOD - A high-resolution digital seismic and gravity sensor includes an inertial mass connected to one or more force-sensitive resonators. The weight of the inertial mass is substantially unloaded with a spring arrangement when exposed to the force of the static gravity field. Seismic accelerations applied to the base of the seismic and gravity sensor, or changes in the gravitational field, generate loads that are transmitted to force-sensitive resonators so that changes in resonant frequency are related to the applied load. The changes in resonant frequency are thus a measure of the seismic accelerations and gravitational field variations. | 02-11-2010 |
20100095765 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 04-22-2010 |
20100095766 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 04-22-2010 |
20100107756 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 05-06-2010 |
20100154536 | GRAVITY GRADIOMETER - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 06-24-2010 |
20100154537 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 06-24-2010 |
20100180680 | INCLINED AXIS GRAVITY GRADIOMETER - Systems for and methods of detecting gravitational acceleration and gravity gradients are disclosed. The systems and methods include gravity gradiometers whose axes are substantially horizontal. In comparison with prior art systems, the systems presently disclosed provide one or both of more accurate measurements for the same amount of space, and smaller space requirements with the same or better accuracy. | 07-22-2010 |
20100288044 | Gravity Sensing Instrument - An instrument for determining the second and/or third-order components of the gravity tensor includes a group of six accelerometers arranged at an equal radius from a spin axis and positioned at 60 degree intervals about the spin axis with the sensing axis of each accelerometer aligned tangentially to the circle subscribed by the accelerometers as they rotate about the spin axis. A gyro-stabilized platform maintains the accelerometer arrangement at a preferred alignment relative to the local gravity vector. As the accelerometers orbit about the spin axis, each accelerometer outputs a sinusoidal signal that is offset by 60 degrees from its immediately adjacent leading and trailing accelerometers with the outputs thereof processed to provide the second-order component and the third-order tensor component. In another arrangement, a group of eight accelerometers arranged at an equal radius from a spin axis and positioned at 45 degree intervals about the spin axis can provide second, third, and fourth-order tensor components. The higher-order tensor components are of use in “de-cluttering” the lower-order tensor components. | 11-18-2010 |
20110138909 | GRAVITY GRADIOMETER - The present disclosure provides a gravity gradiometer that comprises a detector for detecting a gravity gradient. The detector comprises at least one movable sensing element and that is arranged to generate a signal in response to a change in gravity gradient. The gravity gradiometer also comprises a support structure for supporting the detector in an aircraft and a component that is arranged to reduce transmission of an aircraft acceleration to the detector. The at least one movable sensing element and the support structure together are arranged to reduce an influence of the aircraft acceleration on the signal by a factor of at least 10 | 06-16-2011 |
20110162449 | DETECTOR FOR DETECTING GRAVITY GRADIEN - The present disclosure provides a gravity gradiometer which comprises a component comprising a detector for generating a signal in response to a change in gravity gradient experienced by the gravity gradiometer. The gravity gradiometer also comprises a support structure for supporting the component in a manner such that the component is movable relative to the support structure. Further, the gravity gradiometer comprises an acceleration sensor for sensing an acceleration associated with an external acceleration when the gravity gradiometer is exposed to the external acceleration. In addition, the gravity gradiometer comprises an actuator for generating a force on the component as a function of both an acceleration sensed by the acceleration sensor and a response parameter associated with the component. The actuator is arranged to apply a generated force such that transmission of the acceleration from the support structure to the component is reduced. | 07-07-2011 |
20110214503 | COMPACT GRADIOMETER WITH ACCELEROMETER BASED ROTATIONAL CONTROL - A rotational stabilization system and method which allows for greater spatial separation of accelerometer sensors while maintaining or reducing an existing external footprint. | 09-08-2011 |
20110265563 | DETECTOR FOR DETECTING A GRAVITY GRADIENT - The present disclosure provides a gravity gradiometer for detecting a gravity gradient. The gravity gradiometer comprises at least two sensor masses that are pivotable about respective axes and each experience a change in torque in response to a change in gravity gradient whereby the at least two sensor masses move relative to each other in response to the change in gravity gradient and wherein a signal indicative of the gravity gradient is generated in response to the relative movement of the at least two sensor masses. Further, the gravity gradiometer comprises an acceleration sensor for sensing an acceleration associated with an external acceleration applied to the gravity gradiometer. The gravity gradiometer also comprises an actuator for generating an adjustment force that is dependent on an acceleration sensed by the acceleration sensor. The adjustment force is also dependent on a mechanical response parameter associated with at least one of the at least two sensor masses. The adjustment force is applied such that a difference between the magnitudes of the torques experienced by the at least two sensor masses in response to the change in gravity gradient is reduced. | 11-03-2011 |
20110283789 | GRAVITATIONAL GRADIOMETER - Apparatus for the measurement of quasi-static gravity gradients comprising: a flexible ribbon held under tension at both ends; sensing means arranged to detect the transverse displacement of the ribbon from an undisturbed position due to the gravitational field acting on said ribbon and to generate a signal representing the displacement; and output means coupled to said sensing means and responsive to said displacement signal to generate an output signal which is a function of the gravitational gradient tensor of the gravitational field; wherein the ribbon has a non-uniform rigidity profile and/or mass profile along its length such that, in use, the displacement response of the ribbon due to the gravitational gradient of the gravitational field is enhanced and/or the displacement response of the ribbon due to the absolute gravitational acceleration of the gravitational field is suppressed. | 11-24-2011 |
20120174668 | Gravity modulator and gravity-modulation reception - An arrangement of gravity modulator and gravity-modulation receiver where photons or electromagnetic radiation is modulated electronically or mechanically to reach either a solid, liquid or mixed target possibly through or followed by a surrounding medium to produce gravity modulation in the target to effect gravity signaling which is received by a gravity-modulation receiver in or not in physical contact with the target. In the receiver, one or more piezo-electric transducer/s or quartz crystal/s receive the gravity modulation amplified for further signal processing. When not in physical contact with the target, the piezo-electric transducer/s is/are loaded with a resonator mass of natural resonant frequency either equal to, half, one third or one fifth of the frequency of the gravity modulator, the quartz crystal/s is/are gravity biased with a high-density metal piece along one direction of the oscillation mode of the crystal/s with natural resonant frequency similar to the resonator mass. | 07-12-2012 |
20120186342 | Method for Detecting Underground Tunnels - A method for detecting tunnels within an area comprising in one embodiment the steps of providing horizontal tensor gravity gradients for the area, calculating a plurality of gravity gradient vector field pairs from the horizontal tensor gravity gradients, each gravity gradient vector field pair including one gravity gradient vector field and a respective orthogonal gravity gradient vector field, detecting dipolar points and polar source points in each of the one and respective orthogonal gravity gradient vector fields for each gravity gradient vector field pair, identifying the polar source points that are present in one but not in both of the one gravity gradient vector field and the respective orthogonal gravity gradient vector field for each gravity gradient vector field pair to identify endpoints, and distinguishing the endpoints resulting from surface features from the endpoints resulting from tunnels. The polar source points form the endpoints of the tunnels. | 07-26-2012 |
20120210783 | GRAVITY GRADIOMETER AND METHODS FOR MEASURING GRAVITY GRADIENTS - Systems and methods for determining a bias-corrected value of at least one component of a gravity gradient tensor using a gravity gradiometer and a measurement bias of the gravity gradiometer wherein the measurement bias varies with time, by taking at least three measurements with the gravity gradiometer positioned in at least two orientations. Any gravity gradiometer can be used, including a Cross-Component Gravity Gradiometer (CCGG), an Orthogonal Quadrupole Responder (OQR), an In-Line Responder (ILR), a Diagonal-Component Gravity Gradiometer, or a Multi-Component Gravity Gradiometer (MCGG). | 08-23-2012 |
20130042679 | Chip-Scale Optomechanical Gravimeter - An apparatus for measuring a gravitational force includes an optomechanical oscillator that deforms under the gravitational force to cause a shift in resonance associated with the optomechanical oscillator. | 02-21-2013 |
20130055808 | GRAVITY GRADIOMETER WITH CORRECTION OF EXTERNAL DISTURBANCE - The present disclosure provides a method of detecting a change in gravity gradient using a gravity gradiometer. The gravity gradiometer comprises a detector for detecting the change in gravity gradient. The gravity gradiometer further comprises a sensor for generating a disturbance signal in response to an external disturbance. The method comprises the steps of exposing the gravity gradiometer to the external disturbance during operation of the gravity gradiometer. Further, the method comprises the steps of detecting the disturbance signal and receiving an output signal from the detector of the gravity gradiometer. The method also comprises the step of numerically correcting the output signal for an impact that a component of the gravity gradiometer experiences, as a consequence of the external disturbance using a response parameter that associates the external disturbance with a disturbance experienced by that component. | 03-07-2013 |
20140000362 | Gravity Gradiometer | 01-02-2014 |
20140026654 | Interferometric Differential Gradiometer Apparatus and Method - A differential gradient of gravity is directly measured from the interferometric combination of two light beams which reflect from pairs of three freefalling test masses. Optical path lengths of two beam arms change relative to one another because of differential gradient of gravity effects the test masses differently simultaneous freefall. The relatively large background of gravity and the gradient of gravity are eliminated from the measurement while simultaneously achieving a high level of common mode rejection of other spurious influences. | 01-30-2014 |
20140060178 | Chip-Scale Optomechanical Gravimeter - An method and apparatus for measuring gravitational force are described where at least one first radiation can be provided to at least one optomechanical oscillator, the at least one optomechanical oscillator being structured to deform under the gravitational force to cause a shift in resonance associated with the at least one optomechanical oscillator. In addition, at least one second radiation is received from the at least one optomechanical oscillator, wherein the at least one second radiation is associated with the shift in the resonance, and the shift in the resonance can be determined based on the first and second radiations. | 03-06-2014 |
20140190254 | COLD ATOM GRAVITY GRADIOMETER - A cold atom gravity gradiometer system includes a laser source that generates a laser beam that propagates along a propagation direction. The system further includes a reflector that reflects a portion of the laser beam and transmits another portion of the laser beam (the transmitted portion). A second reflector spatially separated from the first reflector along the propagation direction reflects the transmitted portion of the laser beam. | 07-10-2014 |
20150101407 | GRAVITY TRANSDUCER - An airborne gravity-based transducer is disclosed as two embodiments with similar physical structures but different operating principles. The first design includes a particle acting as an active interface characterized by internal vibrations relating to its de Broglie wave, a resonant cavity for trapping the particle, and a phonon-wave source wherein the de Broglie and phonon waves interact over a junction area. In the second design, mechanical displacements between the transducer elements can be monitored through electromechanical transduction. Both designs include a power source and a biasing circuit for producing an electrical current across the junction, and a sensing system for measuring voltage. Both designs are capable of cancelling slowly-varying gravitational acceleration due to dynamic interaction in motion with the gravitational field and responding to small-scale gravity anomalies. The transducer can be utilized in hydrocarbon exploration to provide information on areas conducive to fluid entrapment in the sedimentary column. | 04-16-2015 |
20150107357 | OPTOMECHANICAL DEVICE FOR ACTUATING AND/OR DETECTING MOVEMENT OF A MECHANICAL ELEMENT, IN PARTICULAR FOR GRAVIMETRIC DETECTION - Optomechanical device for actuating and/or detecting movement of a mechanical element, in particular for gravimetric detection. It includes a support with a mechanical element anchored to the support which is designed to move relative to the element, and a device for actuating and/or detecting movement or of variations in frequency of movement of the element. A portion of the device is arranged beneath at least part of the element, between the element and the support. The device includes a fixed optical device with at least one optical waveguide arranged beneath all or part of the element at a determined distance from the element, and which is designed to propagate at least one optical wave having a given wavelength designed to interact with the element. The optical waveguide is at a determined distance from the mechanical element so that the evanescent field of the optical waveguide interacts with the mechanical element. | 04-23-2015 |
20150355370 | HOLD STATE CHANGE DETECTION APPARATUS, HOLD STATE CHANGE DETECTION METHOD, AND COMPUTER READABLE MEDIUM - In order to accurately identify a hold state of a mobile device held by a user while the user is moving, provided is a hold state change detection apparatus including an acquiring section that acquires an output signal of a sensor mounted in the mobile device held by the user; a change detecting section that detects a change in a hold state of the mobile device based on the output signal of the sensor; and a hold state judging section that judges the hold state based on the output signal of the sensor. During a prescribed time from the time when the change detecting section detects the change in the hold state, information indicating the hold state prior to the detection of the change in the hold state is output. Also provided is a hold state change detection method and program. | 12-10-2015 |
20160041300 | SYSTEM AND METHOD FOR GRAVIMETRY WITHOUT USE OF AN INERTIAL REFERENCE - A gravimeter for measuring the gravitational field of the Earth without an inertial reference comprises accelerometer pairs disposed on a platform where the sensitive axis of each accelerometer is arranged on the platform to measure plumb gravity. At least one accelerometer pair is spatially configured to define a baseline therebetween. The gravimeter is positioned so that the baseline is maintained parallel to a linear survey path. Each accelerometer outputs a signal representative of the sum total of the accelerations detected, including accelerations due to gravity and kinematic accelerations of the host vehicle and mounting structure. A processor subtracts the accelerometer pair outputs for common-mode rejection determination of a down gravity gradient and combines with a direct plumb gravity measurement to obtain an enhanced gravity data output that is not subject to frequency limits attributed to the performance limitations of inertial reference devices. | 02-11-2016 |
073383000 | Torsion balance | 5 |
20090260433 | Actuatory and Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 10-22-2009 |
20100101321 | GRAVITY GRADIOMETER WITH TORSION FLEXURE PIVOTS - A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. The quadruple responder further comprises at least two torsion spring flexures. The torsion spring flexures are provided by pins connecting each side of the mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both torsion spring flexures. | 04-29-2010 |
20100101322 | Gravity Gradiometer with Torsion Flexure Pivots - A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said side of said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole. | 04-29-2010 |
20120222481 | QUADRUPOLE RESPONDER FOR OQR-TYPE GRAVITY GRADIOMETER - A quadrupole responder for an OQR-type gravity gradiometer comprises a housing, and a mass quadrupole positioned within the housing. The mass quadrupole has a pair of sides, and also has a center of mass between the sides. At least a pair of torsion spring flexures are provided by pins connecting said sideof said mass quadrupole to the housing. The torsion spring flexures provide an axis of rotation which passes through the center of mass of the mass quadrupole and through both spring flexures. The pins are integral with the mass quadrupole. | 09-06-2012 |
20130008248 | Torsion balance apparatus - The present invention proposes a torsion balance apparatus with high sensitivity and accuracy to measure extremely small rotation angle. The torsion balance apparatus comprises a bar which rotates and is horizontally suspended by a suspending fiber, a light source, a detector and a light reflecting system which reflects the light beam from the light source several times and reaches to the detector. | 01-10-2013 |
073382000 | Gravitational variation | 34 |
20080257039 | Device and Method for the Gravimetric Determination of Liquid Volumes and Analyzer System Comprising Such a Device - A device for the gravimetric volume determination of liquid volumes. The device comprises a housing ( | 10-23-2008 |
20080295594 | METHOD AND APPARATUS FOR MEASUREMENTS OF GRAVITY IN SMALL DIAMETER BOREHOLES - An apparatus for measuring gravity in a small diameter borehole comprises a pressure tube and at least one pendulum gravity sensor accommodated by the pressure tube. The gravity sensor comprises a pendulum and circuitry to monitor generally continuously the swing period and amplitude of the pendulum. | 12-04-2008 |
20090044621 | Accelerometer and Rate Sensor Package for Gravity Gradiometer Instruments - An accelerometer and rate sensor package to aid gravity gradiometers is provided. The accelerometer and rate sensor package is mounted directly on or within a gravity gradiometer instrument (GGI). Outputs from the sensors can be used to reduce unwanted noise due to angular rotational rates, angular accelerations and linear accelerations that may be coupled to the GGI. Since the sensor assembly is directly mounted on or within the GGI, the sensor assembly is coupled to the GGI and senses the acceleration and angular rates as seen by the GGI. Thus, outputs from the GGI can be corrected more effectively using the sensor assembly's outputs. | 02-19-2009 |
20090114013 | APPARATUS AND METHOD FOR IMPROVED LIGHT SOURCE AND LIGHT DETECTOR FOR GRAVIMETER - An instrument for measuring gravitational acceleration from within a borehole, the instrument including: a light source having a semiconductor that comprises a bandgap greater than about two electron volts (eV); and a gravimeter for receiving light from the light source and providing output light with a characteristic related to the gravitational acceleration, the gravimeter implemented at least one of a nano electromechanical system (NEMS) and a micro electromechanical system (MEMS); wherein the light source and the gravimeter are disposed in a housing adapted for insertion into the borehole. | 05-07-2009 |
20090114014 | FORCE AND ACCELERATION SENSOR USING FOUR WAVE MIXING TECHNIQUE - A sensor for measuring force, the sensor including: a light source; and a mixing medium in optical communication with the light source and exposed to the force; wherein four wave mixing of light interacting with the mixing medium provides a signal that indicates the force. | 05-07-2009 |
20090126486 | ORIENTATION INDEPENDENT GRAVITY SENSOR - An instrument for measuring gravitational acceleration, the instrument including: a plurality of accelerometers disposed about a three-dimensional structure, the plurality of accelerometers providing output used for measuring the gravitational acceleration; wherein each accelerometer in the plurality is implemented by at least one of a micro-electromechanical system (MEMS) and a nano-electromechanical system (NEMS). | 05-21-2009 |
20090235740 | Gravity Gradient Sensor - A gravimeter for detecting a gravity difference between two points is disclosed. The gravimeter comprises an interferometric arrangement wherein the length of a reference arm is dependent upon the gravity local to a first accelerometer and the length of a sample arm is dependent upon the gravity local to a second accelerometer. A pair of photodetectors that operate in complimentary fashion provide electrical signals based on a first signal conveyed by the reference arm and a second signal conveyed by the sample arm. A change in the differential gravity between the two points induces equal and opposite changes to the magnitudes of the two electrical signals. | 09-24-2009 |
20090293611 | Gravity Gradiometer - A gravity gradiometer and method for forming a pivot flexure web for a gradiometer is disclosed. The gradiometer has measurement bars | 12-03-2009 |
20090293612 | GRAVITY SENSOR AND ELECTRONIC DEVICE USING THE SAME - A gravity sensor includes a chamber, a number of receiving holes, an electrically insulative liquid, a number of pressure sensors, and a number of sealing elements. The receiving holes are defined in the inner surface of the chamber. The electrically insulative liquid is sealed within the chamber. The pressure sensors are disposed in the receiving holes respectively, and are configured for sensing the pressure that the electrically insulative liquid apply thereto. The sealing elements is configured for sealing the receiving holes respectively when the corresponding pressure sensor senses a pressure applied by the electrically insulative liquid. | 12-03-2009 |
20100071461 | MICROGRAVIMETER FOR GEOPHYSICAL PROSPECTING - An apparatus and a method for measuring the gravitational acceleration on the ground, for example adapted to geophysical explorations applied to mining, comprising a base frame ( | 03-25-2010 |
20100071462 | Gravity Gradiometer - The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass. | 03-25-2010 |
20100083753 | METHOD FOR THE ESTIMATION OF FLUIDS MOVED IN COMPARTMENTED AREAS OF THE SUBSOIL - The present invention relates to a method for estimating fluid volumes moved in compartmented areas of the subsoil, including steps which consist in effecting, in a survey field, a series of gradiometric measurement campaigns “for framing/calibrating the area” at pre-established time intervals, for each of which the relative variation ΔV | 04-08-2010 |
20100116049 | Gravimeter Launch Mechanism - A gravimeter that utilizes an electromagnetic launcher for enabling a free-fall of a test mass is disclosed. The electromagnetic launcher propels the test mass upward such that the test mass begins to free-fall once it has reached the apex of its flight. In addition, in some embodiments, the test mass comprises only non-ferromagnetic materials so that the free-fall of the test mass is unperturbed by magnetically induced influences. | 05-13-2010 |
20100147071 | Matter-Wave Gravimeter Incorporated into an Atom Chip - The general field of the invention is that of gravimeters, of the matter-wave type, allowing the measurement of the gravitational field or of an acceleration in a given direction of measurement. This type of gravimeter uses ultracold atoms to take the measurement. It necessarily comprises an atom trap ( | 06-17-2010 |
20100175472 | Gravity Survey with Relative and Absolute Gravimeters - A gravity survey is conducted by obtaining relative gravity measurements from a plurality of survey points using a relative gravimeter, obtaining absolute gravity measurements from a subset of a lesser plurality of the survey points designated as combination survey points, determining a correction factor related to any difference between the relative and absolute gravity measurements at each of the combination survey points, and correcting the relative gravity measurements made at the survey points which are not combination survey points using the correction factor. The absolute and corrected relative gravity measurements at the survey points constitute the gravity survey. | 07-15-2010 |
20100275686 | INERTIAL SENSING SYSTEM WITH A CURVED BASE AND A DIAMAGNETIC MASS - An inertial sensing system includes a diamagnetic mass, a plurality of permanent magnets positioned to form a curved base, wherein the plurality of permanent magnets are configured to provide an inhomogeneous magnetic field upon which the diamagnetic mass becomes levitated above the plurality of permanent magnets within the curved base and wherein the curved base also provides a confinement potential to substantially prevent the diamagnetic mass from exiting an interior of the curved base, and a tracking apparatus for monitoring at least one of a position and an orientation of the diamagnetic mass with respect to the curved structure. | 11-04-2010 |
20110303005 | METHOD OF DETERMINING THE DIP OF A FORMATION - A method of determining the dip or apparent dip of a section of a subterranean formation is described using the measurements of a borehole gravity meter and a dip-dependent model for the response of the gravity meter. | 12-15-2011 |
20120279296 | METHOD AND APPARATUS FOR MOTION SENSING WITH INDEPENDENT GRIP DIRECTION - A motion sensing technique. A method for motion sensing of a motion sensing apparatus include determining a gravity direction, determining an actual motion, and determining a current motion based on the determined gravity direction, the determined actual motion direction, and a previous motion direction. | 11-08-2012 |
20130031975 | GRADIOMETER - Primarily (but not exclusively) in the field of natural resources exploration, there is a requirement to measure the absolute value and variation of gravity at a given point and over an area gradient, thereby detecting the presence of sub-surface anomalies which give rise to the variation in the measured gravity value. In order to provide a portable, accurate, efficient and cost effective method for making the measurements, a gravity sensing apparatus (ABCD) can be deployed using a variety of vehicles, such as (for example, but not limited to) an aircraft or helicopter, with compensation applied by a motion sensing apparatus (EFGH) to reduce or eliminate the effects of vibration and vehicle motion and structural flexure on the gravity and gravity gradiometry data. | 02-07-2013 |
20130042680 | APPARATUS FOR MEASURING GRAVITATIONAL FORCE AND METHODS OF USING THE SAME - An apparatus for measuring gravitational force is provided having at least one optomechanical oscillator, the at least one optomechanical oscillator having an initial resonance, and a second resonance when displaced by gravitational force; and at least one photonic crystal having at least one cavity coupling optical and mechanical degrees of freedom of the oscillator. | 02-21-2013 |
20130186198 | GRAVITY AXIS DETERMINATION APPARATUS AND MOBILE TERMINAL APPARATUS USING THE SAME - A gravity axis determination apparatus which can determine the gravity direction in a short time. The apparatus is low in cost and has a simple construction. Data values of acceleration data trains in a same time zone are mutually compared and one of the three axes is determined as a gravity axis. | 07-25-2013 |
20130205894 | Interferometric Differential Free-Fall Gradiometer - The invention relates to an interferometric free-fall gravity gradiometer, comprising at least one source of coherent light L and a first retroreflector TM | 08-15-2013 |
20140007677 | ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - A device comprising a laser system ( | 01-09-2014 |
20140013841 | ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - An absolute gravimetric measurement device including, in succession, a laser system, a supporting surface of the laser system, an ultra-vacuum system, a retroreflective mirror, and a seismic attenuation system. The seismic attenuation system includes an upper plate including a hole above which the retroreflective mirror is kept suspended by at least three metallic blades including first ends constrained to a periphery of the plate and second ends above the hole in correspondence with the retroreflective mirror, the metallic blades configured to form a spring-antispring geometry for damping vibrations of the retroreflective mirror. The absolute gravimetric measurement device also includes a mechanism leveling the retroreflective mirror integral with the seismic attenuation system and a radial constraining mechanism between the retroreflective mirror and the upper plate. | 01-16-2014 |
20140026655 | Test Mass and Method for Interferometric Gravity Characteristic Measurement - A test mass used for light beam interferometric gravity characteristic measurement has a center of mass located equidistant and colinear with optical center points of two oppositely reflecting retroreflectors. Rotation of the test mass about its center of mass during freefall changes the path length of the oppositely reflected light beams by equal amounts, thereby achieving common mode cancellation of the effects of test mass rotation when the two reflected light beams are interferometrically combined. | 01-30-2014 |
20140083186 | SYSTEMS, DEVICES AND METHODS FOR BOREHOLE GRAVIMETRY - A gravimeter, a gravimeter system, and a method for measuring gravitational acceleration within a borehole are described herein. The gravimeter includes a proof mass that is constrained by springs and an optical interferometer for measuring displacement of the proof mass. The optical interferometer generates a light path from a light source to a reflective surface on the proof mass. Spatial displacement of the proof mass from a reference position to a position of gravitational equilibrium is determined by measuring a change in length of the light path. In turn, gravitational acceleration can be determined from the spatial displacement of the proof mass. A number of such gravimeters can be used in a gravimeter system to make measurements of gravitational acceleration in variety of different directions. | 03-27-2014 |
20140096606 | DETECTOR OF GRAVITATIONAL WAVES AND METHOD OF DETECTING GRAVITATIONAL WAVES - A semiconductor detector of gravitational waves of a first frequency may include an oscillator having a metal coated oscillating member over a metal coated semiconductor substrate to be subjected to a Casimir attraction force towards the semiconductor substrate. The oscillator may be configured to exert a force to counterbalance the Casimir attraction force causing the oscillating member oscillates with a main harmonic resonance frequency equal to the first frequency. A displacement sensor may be coupled to the substrate and oscillating member and configured to sense oscillations and to generate corresponding sense signals. A pass-band filter may be tuned to the main harmonic resonance frequency and configured to generate band-pass replica signals of the sense signals, and an airtight package may be configured to keep a vacuum between the oscillating member and the semiconductor substrate. An array of semiconductor detectors and a method of detecting gravitational waves are also disclosed. | 04-10-2014 |
20140102191 | PILOTING METHOD OF A LASER SYSTEM OF AN ABSOLUTE GRAVIMETRIC MEASUREMENT DEVICE BY ATOMIC INTERFEROMETRY FOR GEOPHYSICAL APPLICATIONS PARTICULARLY FOR MONITORING HYDROCARBON RESERVOIRS - A piloting method of a laser system of an absolute gravimetric measurement device by atomic interferometry particularly suitable for on-site applications and advantageously usable in the geophysical field, including: generating cooling, entrapment, manipulation, thrust, and detection bands of a plurality of atoms; cooling the plurality of atoms; entrapping the plurality of cooled atoms in a three-dimensional magneto-optical trap; releasing the plurality of atoms in free fall in an ultra-vacuum system; performing an interferometric sequence; performing a detection; wherein the releasing includes quenching the three-dimensional magneto-optical trap through the contemporaneous extinction of the bands for producing a three-dimensional magneto-optical trap and a trap magnetic field. | 04-17-2014 |
20140165720 | ESTIMATING CHANGE IN POSITION OF PRODUCTION TUBING IN A WELL - Characterizing a parameter of interest relating to a formation intersected by a borehole. Methods may include estimating the parameter using at least one gravity measurement adjusted to account for a gravity field gradient associated with a change in a frame of reference caused by removal of a reference feature from the borehole. Methods may also include taking at least one prior gravity measurement before removal of the reference feature from the borehole; taking at least one prior gravity measurement after removal of the reference feature from the borehole; estimating the change in the frame of reference based on the prior gravity measurements taken before and after removal of the reference feature; and adjusting the at least one gravity measurement using the estimated change. | 06-19-2014 |
20140190255 | ULTRA HIGH RESOLUTION GRAVITY GRADIOMETERY TECHNIQUE - A method and system provide the ability to measure relative displacement and rotation. A first light is continuously shined from a first light source that is fixed on a first entity to a first two-dimensional (2D) plate fixed on a second entity. The first direction of propagation of the first light does not change relative to the first entity. A second light is shined from a second light source that is fixed on the first entity to a second 2D plate fixed on the second entity. A second direction of propagation of the second light does not change relative to the first entity and is different from the first direction of propagation. The displacement of the lights on plates is directly monitored to determine a 3D displacement vector that represents a relative displacement between the first entity and the second entity. Thus, a three dimensional gravity gradient tensor is constructed. | 07-10-2014 |
20140260605 | Polarized Beam, Matched Coincident Beam Path, Interferometric Gradiometer Apparatus and Method - A gravity gradient is measured interferometrically from two polarized light beams having mutually different polarization planes which reflect from opposite surfaces of two freefalling test masses. The two polarized light beams project along matched coincident beam paths and divert from the coincident paths to interact with the freefalling test masses. An enhanced level of common mode rejection of adverse influences arises from traversing the coincident beam paths. | 09-18-2014 |
20140318239 | Interferometric Gravimeter Apparatus and Method - A gravity value is measured using two light beams which each reflect from both a freefall test mass and a stationary reference test mass which is inertially supported by a long period isolation device. The optical path lengths of the light beams change equally and oppositely in response to gravity and equally in response to disturbances, resulting in cancellation of the undesirable effects of the disturbances by common mode rejection and in a desirable increase in the number of gravity induced measurement fringes, when the two light beams are combined interferometrically. | 10-30-2014 |
20140338445 | METHOD OF UTILIZING MOBILE DEVICE TO DETECT EMERGENCY AND RELATED EMERGENCY DETECTING SYSTEM - A method of utilizing a mobile device to detect an emergency includes detecting whether the mobile device is carried by a user; detecting an acceleration status of the mobile device when the mobile device is determined to be carried by the user; and determining whether the user is in the emergency according to the acceleration status of the mobile device. | 11-20-2014 |
20150090028 | Atom Interferometry Device for Differential Inertial Measurement - An atom interferometer with differential inertial measurement comprises an atom source system to supply several sets of atoms intended for acceleration measurements which are made simultaneously at different respective locations. The sets of atoms are transported by a dedicated system between an initial position and the locations at which the acceleration measurements are made. The interferometer can be used to obtain highly accurate acceleration or gravity gradient measurement results. | 04-02-2015 |
20150128696 | Superconducting Acceleration Sensor Suitable For Gravitational Wave Radiation Detection - This invention detects mass and mass motion of external objects by virtue of its action as a gravimeter, gravity gradiometer, and detector of gravitational fields. This invention is for devices which function as accelerometers and gyroscopes for the bodies to which they are attached. | 05-14-2015 |
20150331142 | MATTER-WAVE GRAVIMETER WITH MICROWAVE SEPARATION AT THE MAGIC FIELD - The general field of the invention is that of matter-wave gravimeters. The gravimeter according to the invention comprises at least:
| 11-19-2015 |
20160116631 | Method for Producing an Integrated Circuit Pointed Element, and Corresponding Integrated Circuit - A method for producing an integrated circuit pointed element is disclosed. An element has a projection with a concave part directing its concavity towards the element. The element includes a first etchable material. A zone is formed around the concave part of the element. The zone includes a second material that is less rapidly etchable than the first material for a particular etchant. The first material and the second material are etched with the particular etchant to form an open crater in the concave part and thus to form a pointed region of the element. | 04-28-2016 |
20160178792 | GRADIOMETER CONFIGURATION INVARIANT TO LASER PHASE NOISE AND SENSOR ROTATIONS | 06-23-2016 |
20080236277 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 10-02-2008 |
20080257038 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 10-23-2008 |
20080282796 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 11-20-2008 |
20080302179 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-11-2008 |
20080302180 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-11-2008 |
20080307883 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 12-18-2008 |
20090064778 | Gravity Gradiometer System - A methods and apparatus for an improved gravity gradiometer are disclosed. | 03-12-2009 |
20100005882 | Gravity Gradiometer - The present invention provides a method of tuning properties of a gravity gradiometer for measuring components of the gravity gradient tensor. The gravity gradiometer comprises a pair of first and second transversely arranged sensor masses that are arranged for movement about an axis and relative to each other in response to a gravity gradient. The gravity gradiometer further comprises first and second capacitors for sensing and influencing the movement of the first and second sensor masses. The method comprising applying a bias voltage to at least one of the capacitors for generating an electrostatic force which acts on one of the sensor masses and thereby influences the movement of that sensor mass. | 01-14-2010 |
20100031746 | HIGH-RESOLUTION DIGITAL SEISMIC AND GRAVITY SENSOR AND METHOD - A high-resolution digital seismic and gravity sensor includes an inertial mass connected to one or more force-sensitive resonators. The weight of the inertial mass is substantially unloaded with a spring arrangement when exposed to the force of the static gravity field. Seismic accelerations applied to the base of the seismic and gravity sensor, or changes in the gravitational field, generate loads that are transmitted to force-sensitive resonators so that changes in resonant frequency are related to the applied load. The changes in resonant frequency are thus a measure of the seismic accelerations and gravitational field variations. | 02-11-2010 |
20100095765 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 04-22-2010 |
20100095766 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 04-22-2010 |
20100107756 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 05-06-2010 |
20100154536 | GRAVITY GRADIOMETER - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 06-24-2010 |
20100154537 | Gravity Gradiometer - A gravity gradiometer is disclosed which has a sensor in the form of bars ( | 06-24-2010 |
20100180680 | INCLINED AXIS GRAVITY GRADIOMETER - Systems for and methods of detecting gravitational acceleration and gravity gradients are disclosed. The systems and methods include gravity gradiometers whose axes are substantially horizontal. In comparison with prior art systems, the systems presently disclosed provide one or both of more accurate measurements for the same amount of space, and smaller space requirements with the same or better accuracy. | 07-22-2010 |
20100288044 | Gravity Sensing Instrument - An instrument for determining the second and/or third-order components of the gravity tensor includes a group of six accelerometers arranged at an equal radius from a spin axis and positioned at 60 degree intervals about the spin axis with the sensing axis of each accelerometer aligned tangentially to the circle subscribed by the accelerometers as they rotate about the spin axis. A gyro-stabilized platform maintains the accelerometer arrangement at a preferred alignment relative to the local gravity vector. As the accelerometers orbit about the spin axis, each accelerometer outputs a sinusoidal signal that is offset by 60 degrees from its immediately adjacent leading and trailing accelerometers with the outputs thereof processed to provide the second-order component and the third-order tensor component. In another arrangement, a group of eight accelerometers arranged at an equal radius from a spin axis and positioned at 45 degree intervals about the spin axis can provide second, third, and fourth-order tensor components. The higher-order tensor components are of use in “de-cluttering” the lower-order tensor components. | 11-18-2010 |
20110138909 | GRAVITY GRADIOMETER - The present disclosure provides a gravity gradiometer that comprises a detector for detecting a gravity gradient. The detector comprises at least one movable sensing element and that is arranged to generate a signal in response to a change in gravity gradient. The gravity gradiometer also comprises a support structure for supporting the detector in an aircraft and a component that is arranged to reduce transmission of an aircraft acceleration to the detector. The at least one movable sensing element and the support structure together are arranged to reduce an influence of the aircraft acceleration on the signal by a factor of at least 10 | 06-16-2011 |
20110162449 | DETECTOR FOR DETECTING GRAVITY GRADIEN - The present disclosure provides a gravity gradiometer which comprises a component comprising a detector for generating a signal in response to a change in gravity gradient experienced by the gravity gradiometer. The gravity gradiometer also comprises a support structure for supporting the component in a manner such that the component is movable relative to the support structure. Further, the gravity gradiometer comprises an acceleration sensor for sensing an acceleration associated with an external acceleration when the gravity gradiometer is exposed to the external acceleration. In addition, the gravity gradiometer comprises an actuator for generating a force on the component as a function of both an acceleration sensed by the acceleration sensor and a response parameter associated with the component. The actuator is arranged to apply a generated force such that transmission of the acceleration from the support structure to the component is reduced. | 07-07-2011 |
20110214503 | COMPACT GRADIOMETER WITH ACCELEROMETER BASED ROTATIONAL CONTROL - A rotational stabilization system and method which allows for greater spatial separation of accelerometer sensors while maintaining or reducing an existing external footprint. | 09-08-2011 |
20110265563 | DETECTOR FOR DETECTING A GRAVITY GRADIENT - The present disclosure provides a gravity gradiometer for detecting a gravity gradient. The gravity gradiometer comprises at least two sensor masses that are pivotable about respective axes and each experience a change in torque in response to a change in gravity gradient whereby the at least two sensor masses move relative to each other in response to the change in gravity gradient and wherein a signal indicative of the gravity gradient is generated in response to the relative movement of the at least two sensor masses. Further, the gravity gradiometer comprises an acceleration sensor for sensing an acceleration associated with an external acceleration applied to the gravity gradiometer. The gravity gradiometer also comprises an actuator for generating an adjustment force that is dependent on an acceleration sensed by the acceleration sensor. The adjustment force is also dependent on a mechanical response parameter associated with at least one of the at least two sensor masses. The adjustment force is applied such that a difference between the magnitudes of the torques experienced by the at least two sensor masses in response to the change in gravity gradient is reduced. | 11-03-2011 |
20110283789 | GRAVITATIONAL GRADIOMETER - Apparatus for the measurement of quasi-static gravity gradients comprising: a flexible ribbon held under tension at both ends; sensing means arranged to detect the transverse displacement of the ribbon from an undisturbed position due to the gravitational field acting on said ribbon and to generate a signal representing the displacement; and output means coupled to said sensing means and responsive to said displacement signal to generate an output signal which is a function of the gravitational gradient tensor of the gravitational field; wherein the ribbon has a non-uniform rigidity profile and/or mass profile along its length such that, in use, the displacement response of the ribbon due to the gravitational gradient of the gravitational field is enhanced and/or the displacement response of the ribbon due to the absolute gravitational acceleration of the gravitational field is suppressed. | 11-24-2011 |
20120174668 | Gravity modulator and gravity-modulation reception - An arrangement of gravity modulator and gravity-modulation receiver where photons or electromagnetic radiation is modulated electronically or mechanically to reach either a solid, liquid or mixed target possibly through or followed by a surrounding medium to produce gravity modulation in the target to effect gravity signaling which is received by a gravity-modulation receiver in or not in physical contact with the target. In the receiver, one or more piezo-electric transducer/s or quartz crystal/s receive the gravity modulation amplified for further signal processing. When not in physical contact with the target, the piezo-electric transducer/s is/are loaded with a resonator mass of natural resonant frequency either equal to, half, one third or one fifth of the frequency of the gravity modulator, the quartz crystal/s is/are gravity biased with a high-density metal piece along one direction of the oscillation mode of the crystal/s with natural resonant frequency similar to the resonator mass. | 07-12-2012 |
20120186342 | Method for Detecting Underground Tunnels - A method for detecting tunnels within an area comprising in one embodiment the steps of providing horizontal tensor gravity gradients for the area, calculating a plurality of gravity gradient vector field pairs from the horizontal tensor gravity gradients, each gravity gradient vector field pair including one gravity gradient vector field and a respective orthogonal gravity gradient vector field, detecting dipolar points and polar source points in each of the one and respective orthogonal gravity gradient vector fields for each gravity gradient vector field pair, identifying the polar source points that are present in one but not in both of the one gravity gradient vector field and the respective orthogonal gravity gradient vector field for each gravity gradient vector field pair to identify endpoints, and distinguishing the endpoints resulting from surface features from the endpoints resulting from tunnels. The polar source points form the endpoints of the tunnels. | 07-26-2012 |
20120210783 | GRAVITY GRADIOMETER AND METHODS FOR MEASURING GRAVITY GRADIENTS - Systems and methods for determining a bias-corrected value of at least one component of a gravity gradient tensor using a gravity gradiometer and a measurement bias of the gravity gradiometer wherein the measurement bias varies with time, by taking at least three measurements with the gravity gradiometer positioned in at least two orientations. Any gravity gradiometer can be used, including a Cross-Component Gravity Gradiometer (CCGG), an Orthogonal Quadrupole Responder (OQR), an In-Line Responder (ILR), a Diagonal-Component Gravity Gradiometer, or a Multi-Component Gravity Gradiometer (MCGG). | 08-23-2012 |
20130042679 | Chip-Scale Optomechanical Gravimeter - An apparatus for measuring a gravitational force includes an optomechanical oscillator that deforms under the gravitational force to cause a shift in resonance associated with the optomechanical oscillator. | 02-21-2013 |
20130055808 | GRAVITY GRADIOMETER WITH CORRECTION OF EXTERNAL DISTURBANCE - The present disclosure provides a method of detecting a change in gravity gradient using a gravity gradiometer. The gravity gradiometer comprises a detector for detecting the change in gravity gradient. The gravity gradiometer further comprises a sensor for generating a disturbance signal in response to an external disturbance. The method comprises the steps of exposing the gravity gradiometer to the external disturbance during operation of the gravity gradiometer. Further, the method comprises the steps of detecting the disturbance signal and receiving an output signal from the detector of the gravity gradiometer. The method also comprises the step of numerically correcting the output signal for an impact that a component of the gravity gradiometer experiences, as a consequence of the external disturbance using a response parameter that associates the external disturbance with a disturbance experienced by that component. | 03-07-2013 |
20140000362 | Gravity Gradiometer | 01-02-2014 |
20140026654 | Interferometric Differential Gradiometer Apparatus and Method - A differential gradient of gravity is directly measured from the interferometric combination of two light beams which reflect from pairs of three freefalling test masses. Optical path lengths of two beam arms change relative to one another because of differential gradient of gravity effects the test masses differently simultaneous freefall. The relatively large background of gravity and the gradient of gravity are eliminated from the measurement while simultaneously achieving a high level of common mode rejection of other spurious influences. | 01-30-2014 |
20140060178 | Chip-Scale Optomechanical Gravimeter - An method and apparatus for measuring gravitational force are described where at least one first radiation can be provided to at least one optomechanical oscillator, the at least one optomechanical oscillator being structured to deform under the gravitational force to cause a shift in resonance associated with the at least one optomechanical oscillator. In addition, at least one second radiation is received from the at least one optomechanical oscillator, wherein the at least one second radiation is associated with the shift in the resonance, and the shift in the resonance can be determined based on the first and second radiations. | 03-06-2014 |
20140190254 | COLD ATOM GRAVITY GRADIOMETER - A cold atom gravity gradiometer system includes a laser source that generates a laser beam that propagates along a propagation direction. The system further includes a reflector that reflects a portion of the laser beam and transmits another portion of the laser beam (the transmitted portion). A second reflector spatially separated from the first reflector along the propagation direction reflects the transmitted portion of the laser beam. | 07-10-2014 |
20150101407 | GRAVITY TRANSDUCER - An airborne gravity-based transducer is disclosed as two embodiments with similar physical structures but different operating principles. The first design includes a particle acting as an active interface characterized by internal vibrations relating to its de Broglie wave, a resonant cavity for trapping the particle, and a phonon-wave source wherein the de Broglie and phonon waves interact over a junction area. In the second design, mechanical displacements between the transducer elements can be monitored through electromechanical transduction. Both designs include a power source and a biasing circuit for producing an electrical current across the junction, and a sensing system for measuring voltage. Both designs are capable of cancelling slowly-varying gravitational acceleration due to dynamic interaction in motion with the gravitational field and responding to small-scale gravity anomalies. The transducer can be utilized in hydrocarbon exploration to provide information on areas conducive to fluid entrapment in the sedimentary column. | 04-16-2015 |
20150107357 | OPTOMECHANICAL DEVICE FOR ACTUATING AND/OR DETECTING MOVEMENT OF A MECHANICAL ELEMENT, IN PARTICULAR FOR GRAVIMETRIC DETECTION - Optomechanical device for actuating and/or detecting movement of a mechanical element, in particular for gravimetric detection. It includes a support with a mechanical element anchored to the support which is designed to move relative to the element, and a device for actuating and/or detecting movement or of variations in frequency of movement of the element. A portion of the device is arranged beneath at least part of the element, between the element and the support. The device includes a fixed optical device with at least one optical waveguide arranged beneath all or part of the element at a determined distance from the element, and which is designed to propagate at least one optical wave having a given wavelength designed to interact with the element. The optical waveguide is at a determined distance from the mechanical element so that the evanescent field of the optical waveguide interacts with the mechanical element. | 04-23-2015 |
20150355370 | HOLD STATE CHANGE DETECTION APPARATUS, HOLD STATE CHANGE DETECTION METHOD, AND COMPUTER READABLE MEDIUM - In order to accurately identify a hold state of a mobile device held by a user while the user is moving, provided is a hold state change detection apparatus including an acquiring section that acquires an output signal of a sensor mounted in the mobile device held by the user; a change detecting section that detects a change in a hold state of the mobile device based on the output signal of the sensor; and a hold state judging section that judges the hold state based on the output signal of the sensor. During a prescribed time from the time when the change detecting section detects the change in the hold state, information indicating the hold state prior to the detection of the change in the hold state is output. Also provided is a hold state change detection method and program. | 12-10-2015 |
20160041300 | SYSTEM AND METHOD FOR GRAVIMETRY WITHOUT USE OF AN INERTIAL REFERENCE - A gravimeter for measuring the gravitational field of the Earth without an inertial reference comprises accelerometer pairs disposed on a platform where the sensitive axis of each accelerometer is arranged on the platform to measure plumb gravity. At least one accelerometer pair is spatially configured to define a baseline therebetween. The gravimeter is positioned so that the baseline is maintained parallel to a linear survey path. Each accelerometer outputs a signal representative of the sum total of the accelerations detected, including accelerations due to gravity and kinematic accelerations of the host vehicle and mounting structure. A processor subtracts the accelerometer pair outputs for common-mode rejection determination of a down gravity gradient and combines with a direct plumb gravity measurement to obtain an enhanced gravity data output that is not subject to frequency limits attributed to the performance limitations of inertial reference devices. | 02-11-2016 |