US3914731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic wavefront processor
Assignee: United States Department of the Navy
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Filing: 1974-07-03
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Granted: 1975-10-21
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Expires: 1994-07-03
Abstract
Abstract A low frequency sonar beamformer system is described utilizing both frequency scaling and velocity scaling. The system is characterized by the use of frequency adding in the frequency scaling section, and the use of a variable frequency oscillator therein which is controlled to compensate for target range, frequency of received energy, and local water conditions.
Inventors
- 👤 Henry L Warner
- 👤 Henry C Wallace
- 👤 Donald L Folds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:43
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/80; G01S3/802; G01S3/805; G01S3/807; Y; Y10; Y10S; Y10S367/00; Y10S367/902
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
288 words
A sonar system for processing low frequency acoustic energy signals received through a water medium characterized by a plurality of variable conditions, said system comprising, in combination: a first array comprising a plurality of receiving transducers arranged in a first predetermined configuration for receiving said low frequency acoustic energy signals and converting them into corresponding low frequency electrical signals; a controllable frequency local oscillator for providing electrical signals of selected frequency; mixer means for adding said low frequency electrical signals and said local oscillator selected frequency electrical signals to provide higher frequency electrical signals representative of said low frequency acoustic energy signals; housing means defining a cavity; a body of acoustic energy conducting gas contained in said cavity; a second array comprising acoustic energy projecting transducers arranged in a second predetermined configuration which is in a scaled down relationship to said first predetermined configuration, said second array being disposed in contact with said acoustic energy conducting gas and responsive to said higher frequency acoustic energy signals in said gas; acoustic lens means, disposed in said gas, for focusing said higher frequency acoustic signals; a third transducer array comprising receiving transducers for receiving said higher frequency acoustic energy signals focused by said acoustic lens means and converting them to sonar beam related higher frequency electrical signals; signal processing and display means, connected to said third array, for providing a visual representation of said low frequency acoustic energy signals; and control means, connected to said controllable frequency local oscillator, for selecting said selected frequency in accordaNce with at least one of said plurality of variable conditions whereby said focusing of said higher frequency acoustic signals is adjusted automatically in response to changes in said one of said plurality of conditions.
Claim 2
Dependent Claim
288 words
A sonar system for processing low frequency acoustic energy signals received through a water medium characterized by a plurality of variable conditions, said system comprising, in combination: a first array comprising a plurality of receiving transducers arranged in a first predetermined configuration for receiving said low frequency acoustic energy signals and converting them into corresponding low frequency electrical signals; a controllable frequency local oscillator for providing electrical signals of selected frequency; mixer means for adding said low frequency electrical signals and said local oscillator selected frequency electrical signals to provide higher frequency electrical signals representative of said low frequency acoustic energy signals; housing means defining a cavity; a body of acoustic energy conducting gas contained in said cavity; a second array comprising acoustic energy projecting transducers arranged in a second predetermined configuration which is in a scaled down relationship to said first predetermined configuration, said second array being disposed in contact with said acoustic energy conducting gas and responsive to said higher frequency acoustic energy signals in said gas; acoustic lens means, disposed in said gas, for focusing said higher frequency acoustic signals; a third transducer array comprising receiving transducers for receiving said higher frequency acoustic energy signals focused by said acoustic lens means and converting them to sonar beam related higher frequency electrical signals; signal processing and display means, connected to said third array, for providing a visual representation of said low frequency acoustic energy signals; and control means, connected to said controllable frequency local oscillator, for selecting said selected frequency in accordaNce with at least one of said plurality of variable conditions whereby said focusing of said higher frequency acoustic signals is adjusted automatically in response to changes in said one of said plurality of conditions.
Claim 3
Dependent Claim
70 words
A sonar system as defined in claim 1, and wherein said control means comprises: a plurality of generators for providing a plurality of electrical analog signals each corresponding to a respective one of said plurality of conditions; electrical analog signal combining means, connected to said plurality of generators, for providing to said controllable frequency local oscillator an oscillator control signal that is a function of said plurality of analog signals.
Claim 4
Dependent Claim
34 words
A sonar system as defined in claim 2, and wherein: said oscillator means comprises a voltage controlled oscillator; said electrical analog signals are voltage signals; and said signal combining means comprises a summing circuit.
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) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |