Don A Baggett

US Patent:

47898615, Dec 6, 1988

Filed:

Feb 9, 1987

Appl. No.:

7/012412

Inventors:

Don W. Baggett - Torrance CA
Jay G. Herther - Nashua NH
Deborah E. Bassham - San Diego CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G01S 1344

US Classification:

342152

Abstract:

There are derived from the sum and difference signals of a monopulse radar receiver a pair of signatures that quickly and reliably, e. g. , unambiguously, indicates when a target being tracked moves out of the center of the antenna main beam. The sum and difference signals are combined in phase quadrature to form a first vector signature signal. The sum and difference signals are also combined in phase quadrature to form a second vector signature signal so that the phase difference between the signature signals varies with the amplitude of the difference signal. The first and second signatures are compared to detect the phase difference therebetween. Commutated signatures are used to determine the direction of target displacement from the antenna boresight and/or to verify the accuracy of the out of beam indication.