Michael Robert Busby

US Patent:

59579820, Sep 28, 1999

Filed:

Aug 18, 1998

Appl. No.:

9/135884

Inventors:

George C. Hughes - Manhattan Beach CA
Michael J. Wehner - Hawthorne CA
Mark L. Hanson - Redondo Beach CA
D. Hobson Lane - Hermosa Beach CA
Paul A. Lavoie - Manhattan Beach CA
Warren H. Taylor - Gardena CA
Bryan H. Kang - La Mirada CA
Paul Steiner - Rancho Palos Verdes CA
Arnold J. Galloway - Los Angeles CA
Michael Busby - Reno NV

Assignee:

TRW Inc. - Redondo Beach CA

International Classification:

G06F 1500

US Classification:

701 13

Abstract:

A method that allows a space vehicle to determine navigation information represented by the contents of a state vector. The method includes the steps of intermittently receiving navigation signals, initializing the state vector with an estimate of the navigation information, and generating a predicted state vector that represents the predicted values for the navigation information after a predetermined time increment in the future. The method further determines whether a navigation signal has been received within a predetermined window of time from a navigation beacon. If a navigation signal has been received, the method updates the state vector and the contents of the state vector are propagated forward in time to provide an estimate of the navigation information after a predetermined time increment. In some instances, however, a navigation signal is not received within the predetermined window of time. In such situations, the method simply propagates the contents of the predicted state vector forward in time.