Patents Assigned to Zeta Associates, Inc.
  • Patent number: 9797987
    Abstract: A frequency correction for frequency difference of arrival geolocation of transmitted target signals may be provided. A frequency of a target signal may be determined at a first collector based upon a first reference timebase source. A frequency of the target signal may be determined at a second collector based upon a second reference timebase source. An observed frequency of a reference carrier signal based upon the first reference timebase source may be determined at the second collector based upon the second reference timebase source. A relative timebase error between the first collector and the second collector may be calculated based upon a difference between the intended frequency of the reference carrier signal and the observed frequency of the reference carrier signal. A corrected frequency difference for the target signal may be calculated based upon the relative timebase error and a proportional scaling factor.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: October 24, 2017
    Assignee: Zeta Associates, Inc.
    Inventors: John M. Holford, James M. Williams, Michael E. Glidewell
  • Publication number: 20140104108
    Abstract: A frequency correction for frequency difference of arrival geolocation of transmitted target signals may be provided. A frequency of a target signal may be determined at a first collector based upon a first reference timebase source. A frequency of the target signal may be determined at a second collector based upon a second reference timebase source. An observed frequency of a reference carrier signal based upon the first reference timebase source may be determined at the second collector based upon the second reference timebase source. A relative timebase error between the first collector and the second collector may be calculated based upon a difference between the intended frequency of the reference carrier signal and the observed frequency of the reference carrier signal. A corrected frequency difference for the target signal may be calculated based upon the relative timebase error and a proportional scaling factor.
    Type: Application
    Filed: October 15, 2013
    Publication date: April 17, 2014
    Applicant: Zeta Associates, Inc.
    Inventors: John M. Holford, James M. Williams, Michael E. Glidewell