US4864307A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for the automatic recognition of targets from "Doppler" ec
Assignee: LMT Radio Professionnelle
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Filing: 1987-01-28
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Granted: 1989-09-05
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Expires: 2007-01-28
Abstract
Abstract A method and device are provided for the automatic recognition of targets from "Doppler" echoes. The method consists in comparing sequentially the spectra of the "Doppler" signal retransmitted by each target with successions of spectra corresponding to known targets stored in a dictionary memory and indicating the type of target when the spectra of the signal retransmitted by the target have been recognized.
Inventors
- 👤 Jean Potage
- 👤 Vincent Albrieux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:00
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/539; G01S7/02; G01S7/41; G01S7/415; G06; G06V; G06V10/00; G06V10/20; G06V10/255
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
200 words
A device for automatic recognition of targets movable at different speeds from "Doppler" sounds supplied by radar or sonar installations comprising: an A-D converter for converting the Doppler sound into digital signals; spectral analysis means for calculating, for each target during constant time intervals a predetermined number of spectra, each spectra being represented by a predetermined number of spectral coefficients representative of the inverse Fourier transform of the logarithm of each spectra of the signal represented by the successions of samples supplied by the analog converter; means for standardizing the spectral coefficients supplied by the spectral analysis means; means for storing the standardized spectral coefficient during an apprenticeship phase when they correspond to known targets; a comparison operator for comparing after the apprenticeship phase is finished the spectral coefficients supplied by the standardization means with coefficients of each known target stored in the storage means; and a decision means for identifying the target when the spectral coefficients obtained correspond to those of a target stored in the storage means, and when the speed of the target measured by the radar or the sonar installation corresponds to the nature of the target identified by said spectral coefficients in said storage means.
Claim 2
Independent Claim
200 words
A device for automatic recognition of targets movable at different speeds from "Doppler" sounds supplied by radar or sonar installations comprising: an A-D converter for converting the Doppler sound into digital signals; spectral analysis means for calculating, for each target during constant time intervals a predetermined number of spectra, each spectra being represented by a predetermined number of spectral coefficients representative of the inverse Fourier transform of the logarithm of each spectra of the signal represented by the successions of samples supplied by the analog converter; means for standardizing the spectral coefficients supplied by the spectral analysis means; means for storing the standardized spectral coefficient during an apprenticeship phase when they correspond to known targets; a comparison operator for comparing after the apprenticeship phase is finished the spectral coefficients supplied by the standardization means with coefficients of each known target stored in the storage means; and a decision means for identifying the target when the spectral coefficients obtained correspond to those of a target stored in the storage means, and when the speed of the target measured by the radar or the sonar installation corresponds to the nature of the target identified by said spectral coefficients in said storage means.
Claim 3
Dependent Claim
22 words
A device according to claim 1, further including a "Doppler" parameter detector for validating the identified target coupled to the decision means.
Claim 4
Dependent Claim
32 words
A device according to claim 1, wherein the decision means comprise means for reinitializing the comparison of the spectral coefficients when the "Doppler" parameters obtained do not correspond with the identified target.
Claim 5
Dependent Claim
14 words
A device according to claim 1, wherein the comparison operator effects the comparison linearly.
Claim 6
Dependent Claim
18 words
A device according to claim 1, wherein the comparison operator effects the comparison by a dynamic programming method.
Claim 7
Dependent Claim
46 words
A device according to claim 1, further comprising means for detecting the "Doppler" frequency of the signal retransmitted by the target and for checking the coherence between the nature of the target indicated by comparison of the spectra and the speed indicated by the "Doppler" frequency.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-04 | 1993-03-06 | 1993-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-04 | 1997-03-06 | 1997-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-04 | 2001-03-06 | 2001-09-05 | $7700.00 | Window Closed / Lapsed |