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:
Jan. 02, 1996
Filed:
Dec. 12, 1984
John P Kuhn, Liverpool, NY (US);
Thomas S Heath, Syracuse, NY (US);
Martin Marietta Corporation, Syracuse, NY (US);
Abstract
The invention discloses an apparatus for and a method of adaptively processing a sonar power spectrum for improving the display of narrowband line structure characteristic of a target in a background of broadband interference which is rippled due to multipath propagation arrival structure. The processor employs a first Fourier transformer to convert the sonar frequency data into a complex correlation format. The autocorrelation is then time difference sampled to separate the broadband ripple interference from the broadband trend interference. The separate time difference samples are then transformed back to their real frequency format to form a broadband ripple estimate and a broadband trend estimate of the interference background. The ripple estimate is subtracted from the sonar signal to remove the ripple component and the resulting difference is normalized by a division by the interference trend estimate. The result is improved detectability of the narrowband lines in the presence of widely varying multipath interference.