Patents by Inventor James H. Africa, JR.

James H. Africa, JR. 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: 10254393
    Abstract: A method for filtering spatial error from a measurement vector is provided to correct for roll, pitch and yaw angular motion. The method includes the following operations: Establish an unstabilized body reference frame. Convert the measurement vector to an unstabilized state vector xU in the unstabilized body reference frame. Establish a stabilized East-North-Up (ENU) reference frame. Calculate an unstabilized pre-transform covariance matrix MU from position variance of the body reference frame. Measure roll, pitch and yaw in the body reference frame as respective angle values (r, p, w). Calculate a transform matrix T between the body reference frame and the ENU reference frame. Calculate a stabilized data vector xS=TxU from the transform matrix and the unstabilized state vector. Calculate a measured angle error sensitivity matrix MA from the angle values. Calculate a tri-diagonal angle error component matrix ME with square values of angle variance of the body reference frame.
    Type: Grant
    Filed: March 28, 2016
    Date of Patent: April 9, 2019
    Inventors: Denis Hugh McCabe, James H. Africa, Jr.
  • Publication number: 20170276783
    Abstract: A method for filtering spatial error from a measurement vector is provided to correct for roll, pitch and yaw angular motion. The method includes the following operations: Establish an unstabilized body reference frame. Convert the measurement vector to an unstabilized state vector xU in the unstabilized body reference frame. Establish a stabilized East-North-Up (ENU) reference frame. Calculate an unstabilized pre-transform covariance matrix MU from position variance of the body reference frame. Measure roll, pitch and yaw in the body reference frame as respective angle values (r, p, w). Calculate a transform matrix T between the body reference frame and the ENU reference frame. Calculate a stabilized data vector xS=TxU from the transform matrix and the unstabilized state vector. Calculate a measured angle error sensitivity matrix MA from the angle values. Calculate a tri-diagonal angle error component matrix ME with square values of angle variance of the body reference frame.
    Type: Application
    Filed: March 28, 2016
    Publication date: September 28, 2017
    Applicant: United States of America, as represented by the Secretary of the Navy
    Inventors: Denis Hugh McCabe, James H. Africa, Jr.
  • Patent number: 8914253
    Abstract: A computer-implemented analysis method is provided for identifying a flight trajectory of a bogey relative to earth's surface. The method includes a first step of obtaining first and second altitudes and velocities of the bogey separated by a first time interval. The second step calculates a first difference between the first and second velocities divided by the first time interval to obtain an acceleration vector. The third step determines the direction of the velocity vector. The fourth step determines whether direction of the second velocity vector exceeds an upward pointing threshold. The fifth step determines whether the acceleration vector is negative and substantially perpendicular to earth's surface as a second result being valid. The sixth step reports that the bogey represents a ballistic projectile in response to the first and second results.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: December 16, 2014
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: James H. Africa, Jr., Thomas G. Poley, Joshua C. Hickland
  • Patent number: 8650000
    Abstract: A computer-implemented analysis method is provided for identifying a flight trajectory of a bogey relative to earth's surface. The method includes a first step of obtaining first and second altitudes and velocities of the bogey separated by a first time interval. The second step calculates a first difference between the first and second velocities divided by the first time interval to obtain an acceleration vector. The third step calculates an acceleration magnitude from the acceleration vector. The remaining steps characterize the vectors and magnitude to report whether the bogey represents a ballistic projectile in a particular phase of Boost, Apogee or Descent.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: February 11, 2014
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: James H. Africa, Jr., Thomas G. Poley
  • Publication number: 20120316823
    Abstract: A computer-implemented analysis method is provided for identifying a flight trajectory of a bogey relative to earth's surface. The method includes a first step of obtaining first and second altitudes and velocities of the bogey separated by a first time interval. The second step calculates a first difference between the first and second velocities divided by the first time interval to obtain an acceleration vector. The third step calculates an acceleration magnitude from the acceleration vector. The remaining steps characterize the vectors and magnitude to report whether the bogey represents a ballistic projectile in a particular phase of Boost, Apogee or Descent.
    Type: Application
    Filed: February 14, 2012
    Publication date: December 13, 2012
    Applicant: United States Government, as represented by Secretary of the Navy
    Inventors: James H. Africa, JR., Thomas G. Poley
  • Publication number: 20120316824
    Abstract: A computer-implemented analysis method is provided for identifying a flight trajectory of a bogey relative to earth's surface. The method includes a first step of obtaining first and second altitudes and velocities of the bogey separated by a first time interval. The second step calculates a first difference between the first and second velocities divided by the first time interval to obtain an acceleration vector. The third step determines the direction of the velocity vector. The fourth step determines whether direction of the second velocity vector exceeds an upward pointing threshold. The fifth step determines whether the acceleration vector is negative and substantially perpendicular to earth's surface as a second result being valid. The sixth step reports that the bogey represents a ballistic projectile in response to the first and second results.
    Type: Application
    Filed: December 8, 2010
    Publication date: December 13, 2012
    Applicant: United States Government, as represented by the Secretary of the Navy
    Inventors: James H. Africa, JR., Thomas G. Poley, Joshua C. Hickland