1
Manik Talwani, Walter K Feldman, Melvin Schweitzer: System and process for secondary hydrocarbon recovery. Lockheed Martin Corporation, Snider & Associates, October 22, 2002: US06467543 (214 worldwide citation)

A hydrocarbon reservoir undergoing secondary recovery is subject to a first and then at least a second gravity gradient survey in which a gravity gradiometer takes gradient measurements on the surface above the reservoir to define successive data sets. The differences between the first and subsequen ...


2
John Barry French, Kieran A Carroll, Steven J Thorpe: Gravity gradiometer. Gedex, Bereskin and Parr, April 22, 2008: US07360419 (44 worldwide citation)

A gravity gradiometer having quadrupole responders in which a mass quadrupole is supported by a torsional spring forming a flexure allowing rotation of the mass quadrupole about its center of mass. The flexure can be a pair of spaced apart posts. The flexure can be made from glassy metal having at r ...


3
Ho J Paik: Three-axis superconducting gravity gradiometer. University of Maryland College Park, Oblon Fisher Spivak McClelland & Maier, June 27, 1989: US04841772 (44 worldwide citation)

Each accelerometer includes a cylindrical proof mass made of a superconducting material. Each proof mass includes annular upper and lower hollowed out portions longitudinally surrounded by a cylindrical exterior wall. Common mode and differential mode sensing coils are arranged adjacent a bottom-sid ...


4
Graeme Joseph O Keefe, James Beresford Lee, Robert John Turner, Gregory John Adams, Graham Clifford Goodwin: Gravity gradiometer. The Broken Hill Proprietary Company, Olson & Hierl, July 13, 1999: US05922951 (43 worldwide citation)

This invention concerns improvements in the performance of a mobile gravity gradient instrument (GGI). Gravity gradiometers measure one or more components of the gradient of gravity which is expressed as the gradient of a gravity vector, or in other words a tensor. The instrument comprises a first, ...


5
Albert Jircitano, Daniel E Dosch: Gravity aided inertial navigation system. Textron, Bean Kauffman & Spencer, August 23, 1994: US05339684 (36 worldwide citation)

An autonomous covert Inertial Navigation System uniquely suited for underwater applications wherein Schuler and siderial errors are bounded without external navigation aids or active instrumentation of ground speed is achieved by integrating a conventional Inertial Navigation System with a gravity g ...


6
Bernard Etkin, John Barry French, Bjarni V Tryggvason, Frank J van Kann: Gravity gradiometry. Business Arts, George A Seaby, January 4, 2005: US06837106 (35 worldwide citation)

A gravity gradiometer is combined with a two-stage actively controlled isolation system. The gravity gradiometer and two stage isolation system may then be mounted within (or on) a mobile vehicle such as, for example, an aircraft. It has been recognized by the inventors herein that the accelerations ...


7
Michael Thomas Gladwin: Gravity meter. The Commonwealth of Australia Commonwealth Scientific and Industrial Research Organization, Jacobson Price Holman & Stern PLLC, July 4, 2000: US06082194 (35 worldwide citation)

A gravity gradiometer including first and second proof masses and a device for providing simultaneous free flight of the proof masses under the influence of the gravitional force in which the gradient is to be measured and a capacitance device for monitoring the movement of the centers of mass with ...


8
Giles M Hofmeyer, Clive A Affleck: Rotating accelerometer gradiometer. Textron Incorporated, Perman & Green, October 25, 1994: US05357802 (35 worldwide citation)

A gravity gradiometer and method for measurement of changes in the intensity of a gravitational field experienced during traversal over earth's terrain, or past a massive object, has a set of eight accelerometers disposed on rotating disc, or on a pair of parallel discs, and arranged uniformly about ...


9
Frank Joachim Van Kann, Michael Joslin Buckingham: Gravity gradiometer with flexural pivot bearing. The University of Western Australia, RTZ Mining and Exploration, Sughrue Mion Zinn Macpeak & Seas, September 16, 1997: US05668315 (34 worldwide citation)

A gravity gradiometer for measuring off-diagonal components of the gravitational gradient tensor includes a housing having a pair of electromagnetic shield enclosures (22, 23) arranged one inside the other, and a body (25) including superconducting material mounted within the inner enclosure (23) fo ...


10
John Morris Lumley, Ho Jung Paik: Proof mass support and sensing system. Oxford Instruments, Staas & Halsey, October 6, 1998: US05817939 (33 worldwide citation)

A proof mass support system has a pair of alignment coils for controlling the rest position of an elongate proof mass. The alignment coils are constructed to provide a levitation force when they carry electric currents which varies along the length of the proof mass. The relative strength of the ele ...