US5164731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbulence radar system
Assignee: Northrop Grumman Systems Corp
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Filing: 1991-06-13
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Granted: 1992-11-17
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Expires: 2011-06-13
Abstract
Abstract The present invention is a radar system that detects turbulence by breaking a range cell return down into spectral segments using an FFT processor. The standard deviation of the spectrum is determined and the system compares that standard deviation to a reference threshold of a non-turbulent return if the signal is above noise. If the threshold is exceeded, the range cell is marked for turbulence display. Once the turbulence display is completed it is overlayed on the weather display. To improve matching of the feature size to the variance calculation the invention performs both range and azimuth post detection integration subsequent to the FFT but before variance calculation.
Inventors
- 👤 Scott C. Borden
- 👤 Bruce D. Mathews
- 👤 Joseph Stevenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:49
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/88; G01S13/95; G01S13/953; Y; Y02; Y02A; Y02A90/00; Y02A90/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
51 words
A method of radar turbulence detection, comprising: (a) obtaining a spectrum of a range cell radar return by performing a Fast Fourier Transformer on said radar return; (b) determining a statistic of the spectrum; (c) comparing the statistic to a threshold; and (d) indicating turbulence when the statistic exceeds the threshold.
Claim 2
Independent Claim
51 words
A method of radar turbulence detection, comprising: (a) obtaining a spectrum of a range cell radar return by performing a Fast Fourier Transformer on said radar return; (b) determining a statistic of the spectrum; (c) comparing the statistic to a threshold; and (d) indicating turbulence when the statistic exceeds the threshold.
Claim 3
Dependent Claim
25 words
A method as recited in claim 1, further comprising, prior to step (b) and subsequent to step (a) performing range and azimuth post detection integration.
Claim 4
Dependent Claim
19 words
A method as recited in claim 1, wherein step (d) includes indicating the turbulence on a weather map display.
Claim 5
Dependent Claim
29 words
The method as recited in claim 1, wherein step (c) comprises comparing the statistic to a defined threshold value having a spectrum spread of about 5 meters per second.
Claim 6
Dependent Claim
57 words
A radar turbulence system, comprising: means for producing a spectrum from a radar range cell return by performing a Fast Fourier Transformer on said radar range cell return; means for comparing a standard deviation of said produced spectrum with a threshold and for indicating turbulence when the threshold is exceeded; and means for displaying the turbulence indication.
Claim 7
Dependent Claim
57 words
A radar turbulence system, comprising: means for producing a spectrum from a radar range cell return by performing a Fast Fourier Transformer on said radar range cell return; means for comparing a standard deviation of said produced spectrum with a threshold and for indicating turbulence when the threshold is exceeded; and means for displaying the turbulence indication.
Claim 8
Dependent Claim
19 words
A system as recited in claim 5, further comprising integration means for performing range and azimuth post detection integration.
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) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |