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. 17, 2020
Filed:
Oct. 16, 2017
Lockheed Martin Corporation, Bethesda, MD (US);
Tod M. Schuck, Lumberton, NJ (US);
David B. Reese, Folcroft, PA (US);
Mark A. Friesel, Ewing, NJ (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A Doppler radar system includes a Doppler radar processor, a memory in communication with radar processor and a transmit/receive controller. The memory includes computer readable instructions that cause the Doppler radar processor to transmit a radar signal toward the airborne object at a frequency; receive reflected radar signals off of the airborne object, including frequencies produced as a result of Doppler effect due to relative motion between features of the airborne object and the radar system; and Fourier transform the received signals into the frequency domain. Peak frequencies and their harmonic frequency families are sorted and identified. The logarithm of the Fourier transform is calculated to generate a quefrency cepstrum. To identify features producing cyclic, periodic Doppler frequency patterns, peak quefrencies and rahmonic families associated with a quefrency peak are sorted and identified. The rotational state of the airborne object based on the identified quefrency families is determined.