Patent US4089002A successfully refreshed from Google Patents.
US4089002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CFAR threshold adaptive target coordinate extractor
Assignee: Bendix Corp
•
Filing: 1977-04-05
•
Granted: 1978-05-09
•
Expires: 1997-04-05
Abstract
Abstract The positive portion of the differentiated negative envelope of a detected radar return signal is divided into range cells. The first range cell is taken and doubled to provide a first and succeeding range cell to comprise a Doublet. The Doublets are integrated in a sliding window detector and beam split to supply the target coordinates.
Inventors
- 👤 Leo A. Kerr
- 👤 Allen I. Sinsky
- 👤 Richard Gonsalves
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:12
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/28; G01S7/285; G01S7/292; G01S7/2923
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
159 words
A target coordinate extractor for a radar system which transmits a plurality of pulses at various contiguous scanning angles comprising a plurality of scans and including a radar receiver having a range clock, means for detecting the envelope of a radar target return signal comprising: means responsive to said range clock for generating a range cell signal comprised of at least a single range cell and defining the peak of said envelope; means for adding at least a contiguous range cell to said range cell signal, implying the presence of a target return in each of the range cells of said range cell signal; an M of N window detector, where M and N are integers; for detecting the presence of a target return in at least M range cells at a certain fixed range in N contiguous scans; and, means responsive to the output signals from said window detector for determining the angular location of said radar target.
Claim 2
Dependent Claim
159 words
A target coordinate extractor for a radar system which transmits a plurality of pulses at various contiguous scanning angles comprising a plurality of scans and including a radar receiver having a range clock, means for detecting the envelope of a radar target return signal comprising: means responsive to said range clock for generating a range cell signal comprised of at least a single range cell and defining the peak of said envelope; means for adding at least a contiguous range cell to said range cell signal, implying the presence of a target return in each of the range cells of said range cell signal; an M of N window detector, where M and N are integers; for detecting the presence of a target return in at least M range cells at a certain fixed range in N contiguous scans; and, means responsive to the output signals from said window detector for determining the angular location of said radar target.
Claim 3
Dependent Claim
53 words
The target coordinate extractor of claim 1 wherein said means for generating a range cell signal comprises: means for selecting one of the leading and trailing halves of the differential of said envelope; and, a noise adaptive constant false alarm rate threshold responsive to said range clock for generating said range cell signal.
Claim 4
Dependent Claim
147 words
The target coordinate extractor of claim 2 wherein said radar system includes a range counter responsive to said range clock for providing a count which is a measure of the range of an instantaneous target return signal and a scanning angle counter which provides a count which is a measure of the instantaneous pointing angle of the radar beam and wherein said means for determining angular location comprises: beginning of target logic means for recording the count in said scanning angle counter upon the occurrence of the first of a range cell signal at a certain range; and, end of target logic means for determining the average of the instantaneous count in said scanning angle counter and the recorded count upon the occurence of the last of a range cell signal at a certain range, said average being related to the angular location of said radar target.
Claim 5
Dependent Claim
64 words
The target coordinate extractor of claim 3 wherein at least said window detector provides a predetermined fixed error bias to the angular location determined by said end of target logic means and with additionally; means for storing a bias correction signal related to said fixed error bias; and, means for adding said bias correction signal to said average to remove the error bias therein.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |