公开(公告)号：US11378673B2

公开(公告)日：2022-07-05

申请号：US17098985

申请日：2020-11-16

申请人： Lockheed Martin Corporation

发明人： Tod M. Schuck ,  David B. Reese ,  Mark A. Friesel

IPC分类号： G01S13/58 ,  G01S7/41 ,  F41H11/02

摘要： 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.

公开(公告)号：US20210263140A1

公开(公告)日：2021-08-26

申请号：US17098985

申请日：2020-11-16

申请人： Lockheed Martin Corporation

发明人： Tod M. Schuck ,  David B. Reese ,  Mark A. Friesel

IPC分类号： G01S13/58 ,  G01S7/41

摘要： 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.

公开(公告)号：US20180106889A1

公开(公告)日：2018-04-19

申请号：US15784889

申请日：2017-10-16

申请人： Lockheed Martin Corporation

发明人： Tod M. Schuck ,  David B. Reese ,  Mark A. Friesel

IPC分类号： G01S7/41 ,  G01S13/42 ,  G01S13/58

CPC分类号： G01S7/411 ,  G01S7/412 ,  G01S7/415 ,  G01S13/42 ,  G01S13/56 ,  G01S13/582 ,  G01S13/886

摘要： A method for classifying an airborne object detected by a radar system is disclosed. The method includes the steps of identifying quefrency peaks in a quefrency cepstrum generated from a received radar return signal, the quefrency peaks indicative of a rotating physical feature of the airborne object. A rotational velocity of the physical feature is determined based on the quefrency peaks. The method further includes determining at least one parameter or characteristic of a physical feature of the airborne object. The at least one characteristic is compared to a known physical feature stored in a classifier database, wherein a classification decision is made upon identifying a match between the at least one characteristic and a known physical feature stored in the database.

公开(公告)号：US20180136326A1

公开(公告)日：2018-05-17

申请号：US15785376

申请日：2017-10-16

申请人： Lockheed Martin Corporation

发明人： Tod M. Schuck ,  David B. Reese ,  Mark A. Friesel

IPC分类号： G01S13/58

CPC分类号： G01S13/583 ,  F41H11/02 ,  G01S7/415

摘要： 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.