David P Hurley

US Patent:

8639476, Jan 28, 2014

Filed:

Jan 31, 2012

Appl. No.:

13/385465

Inventors:

Craig A. Martell - Spotsylvania VA, US
John A. Lawton - King George VA, US
David B. Hurley - Fredericksburg VA, US

Assignee:

The United States of America as Represented by the Secretary of the Navy - Washington DC

International Classification:

F42B 15/01
F42B 15/12

US Classification:

702196, 702142, 702150, 702190

Abstract:

A computer-implemented method is provided for generating the estimation of current position, velocity and acceleration state vectors and associated uncertainty estimation (covariance) of a boosting ballistic missile. The method includes constructing a state tensor of the projectile from a plurality of sensor measurements in Earth-Centered, Earth-Fixed (ECEF) coordinates; translating the state tensor to Cartesian coordinates as a transform state; determining a covariance matrix from the transform state; updating the transformed state as an updated transform state; and updating the covariance matrix as an updated covariance. The process can further include adjusting the covariance matrix by an approximate transition matrix and a process noise matrix. The noise matrix can be translated from a local noise matrix based on a propagation time-step, a scaling parameter, and a bias process noise level. A time-of-flight in the state tensor can be updated by smoothing from a launch event.