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:
Nov. 18, 1997
Filed:
Aug. 02, 1996
Nai K Shi, Huntington Beach, CA (US);
Henry F Williams, Temecula, CA (US);
Boeing North American, Inc., Seal Beach, CA (US);
Abstract
The blade flash signature in a radar return is enhanced and used to detect and classify helicopter targets. The radar return of a target is fast Fourier transformed 34, and the frequencies corresponding to DC and the body of the target are filtered out 38. The filtered signal is inverse transformed 44, moving averaged 52, and auto-correlated 54. Auto-correlation 54 may take place in the frequency domain. If there are significant peaks in the auto-correlation output (other than at zero time delay), then a helicopter is present. The time delay between peaks is the period of the blade. The height of the peak indicates whether it is the main blade or the tail blade which has been detected, and allows a signal indicating both periods to be output. The main blade period and the ratio of the period to that of the tail blade can be compared with a data base to classify the helicopter.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile