Patents by Inventor Daniel J. DiFrancesco

Daniel J. DiFrancesco has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8347711
    Abstract: A full-tensor, gravity gradient measuring system is disclosed that is based on atom interferometry. Each axis in the three-axis measuring system is served by a different gravity gradiometer, where each gradiometer comprises three pairs of atom interferometric (AI) accelerometers. The accelerometers in each pair are mounted on opposite sides of the gradiometer's rotation axis from each other. The three AI accelerometer pairs are step-rotated, instead of being continuously rotated, thereby providing enhanced signal-to-noise performance. The three gradiometers in the overall measuring system are mounted orthogonally with respect to one another on a local-level platform, in order to achieve a full-tensor measuring system. The measuring system can be step-rotated as an overall unit around an axis perpendicular to a local level reference.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: January 8, 2013
    Assignee: Lockheed Martin Corporation
    Inventors: Hugh F. Rice, Jack C. Lindell, Daniel J. DiFrancesco
  • Publication number: 20100064767
    Abstract: A full-tensor, gravity gradient measuring system is disclosed that is based on atom interferometry. Each axis in the three-axis measuring system is served by a different gravity gradiometer, where each gradiometer comprises three pairs of atom interferometric (AI) accelerometers. The accelerometers in each pair are mounted on opposite sides of the gradiometer's rotation axis from each other. The three AI accelerometer pairs are step-rotated, instead of being continuously rotated, thereby providing enhanced signal-to-noise performance. The three gradiometers in the overall measuring system are mounted orthogonally with respect to one another on a local-level platform, in order to achieve a full-tensor measuring system. The measuring system can be step-rotated as an overall unit around an axis perpendicular to a local level reference.
    Type: Application
    Filed: September 15, 2008
    Publication date: March 18, 2010
    Applicant: LOCKHEED MARTIN CORPORATION
    Inventors: Hugh F. Rice, Jack C. Lindell, Daniel J. DiFrancesco
  • Patent number: 6212952
    Abstract: Gravity gradient measurements taken by an accelerometer type gradiometer are optimized by tilting the measuring plane of the instrument by a selected angle above and below the horizontal to obtain data that can be differenced or otherwise processed to remove instrument bias and by taking data at first and then at a second orthogonal azimuth heading to obtain absolute non-relative gradient measurements.
    Type: Grant
    Filed: February 18, 2000
    Date of Patent: April 10, 2001
    Assignee: Lockheed Martin Corporation
    Inventors: Melvin Schweitzer, Walter K. Feldman, William F Konig, Daniel J. DiFrancesco, David L. Sieracki, Carlo P. San Giovanni
  • Patent number: 6125698
    Abstract: Gravity gradient measurements taken by an accelerometer type gradiometer are optimized by tilting the measuring plane of the instrument by a selected angle above and below the horizontal to obtain data that can be differenced or otherwise processed to remove instrument bias and by taking data at first and then at a second orthogonal azimuth heading to obtain absolute non-relative gradient measurements.
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: October 3, 2000
    Assignee: Lockheed Martin Corporation
    Inventors: Melvin Schweitzer, Walter K. Feldman, William F Konig, Daniel J. DiFrancesco, David L. Sieracki, Carlo P. San Giovanni