The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 10, 2001
Filed:
Dec. 07, 1990
Timothy A. Geldart, Gaithersburg, MD (US);
Alvin F. Martin, Potomac, MD (US);
James D. Mosko, Germantown, MD (US);
Fred J. Goodman, Gaithersburg, MD (US);
General Dynamics Government Systems Corporation, Needham, MA (US);
Abstract
An algorithm for emitter identification of a transmitting platform using spectral energy analysis, and a system utilizing said algorithm, wherein said algorithm processes audio signals from transmission data using a fast fourier transform, detecting gaps in said processed transmission data. It then extracts spectral features consisting of normalized energy per unit frequency from said gaps. The algorithm and system then proceed to execute a decision function based on said extracted characteristic features to identify the platform of said transmitter based on said features. A second algorithm, which may be executed in parallel with the first by said system, processes the same transmission data to detect transmission activity on a radio channel in the audio frequency range, and to detect the boundaries of transmitter keyclicks at the beginning and end of said transmission. The algorithm extracts keying envelopes from said detected keyclick boundaries, and analyzes said keying envelopes to extract features characteristic of said keyclicks. The algorithm and system then correlate identification of said emitter platforms based on said extracted spectral features with identification of said emitter platforms based on said extracted keyclick features.