US4056802A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sonar alarm system
Assignee: United States Department of the Navy
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Filing: 1976-03-10
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Granted: 1977-11-01
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Expires: 1996-03-10
Abstract
Abstract A sonar system is disclosed which processes received sonic energy echo sils in such manner as to determine whether or not a marine mine or other object of significance is laying on a particular area of sea floor being sonically scanned or searched and, in addition, whether or not said marine mine or other object has a sonic energy shadow behind it. If and when such two conditions are met, an alarm is given to the human operator monitoring the subject sonar system, so as to call his attention to the fact that a target of significance has been acquired.
Inventors
- 👤 James L. Rabon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:00
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8902; Y; Y10; Y10S; Y10S367/00; Y10S367/901
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
255 words
In combination with a reflective object detecting sonar system including transmitter means for projecting pulses of sonic energy at predetermined sweep intervals and receiver means for providing first electrical signals representative of reflected sonic energy, a target alarm system comprising: highlight detector means, responsive to said first electrical signals, for providing a second electrical signal corresponding to each highlight reflection of at least a predetermined strength; shadow detector means, responsive to said first electrical signals, for providing a third electrical signal corresponding to each substantial absence of reflected energy for a predetermined time period; single shot means, responsive to said second electrical signals, for providing a fourth electrical signal for a predetermined time period after initiation; coincidence gate means, responsive to coincidence of said second and said fourth electrical signals, for providing fifth electrical signals each representative of a detected highlight reflection followed by a detected shadow, said fifth electrical signals occurring at times in a given sweep interval corresponding to the ranges of reflective objects giving rise to detected highlights and associated shadows; range memory means, responsive to occurrences of said fifth electrical signals in a given sweep interval, for initiating sixth electrical signals at times in the following sweep interval corresponding to said ranges; and target alarm means, responsive to coincidence of at least one of said fifth signals and a corresponding one of said sixth signals, for providing a perceptible output signal corresponding to detection of a highlight and associated shadow at substantially the same range on at least two successive sweeps.
Claim 2
Dependent Claim
255 words
In combination with a reflective object detecting sonar system including transmitter means for projecting pulses of sonic energy at predetermined sweep intervals and receiver means for providing first electrical signals representative of reflected sonic energy, a target alarm system comprising: highlight detector means, responsive to said first electrical signals, for providing a second electrical signal corresponding to each highlight reflection of at least a predetermined strength; shadow detector means, responsive to said first electrical signals, for providing a third electrical signal corresponding to each substantial absence of reflected energy for a predetermined time period; single shot means, responsive to said second electrical signals, for providing a fourth electrical signal for a predetermined time period after initiation; coincidence gate means, responsive to coincidence of said second and said fourth electrical signals, for providing fifth electrical signals each representative of a detected highlight reflection followed by a detected shadow, said fifth electrical signals occurring at times in a given sweep interval corresponding to the ranges of reflective objects giving rise to detected highlights and associated shadows; range memory means, responsive to occurrences of said fifth electrical signals in a given sweep interval, for initiating sixth electrical signals at times in the following sweep interval corresponding to said ranges; and target alarm means, responsive to coincidence of at least one of said fifth signals and a corresponding one of said sixth signals, for providing a perceptible output signal corresponding to detection of a highlight and associated shadow at substantially the same range on at least two successive sweeps.
Claim 3
Dependent Claim
134 words
The combination defined in claim 1, and wherein said range memory means comprises: at least a first range memory circuit; said first range memory circuit comprising a coincidence gate, a first single-shot element and a second single-shot element; said coincidence gate being responsive to a first of said fifth electrical signals in a given sweep interval to trigger said first single-shot element to change from a first state to a second state for a first predetermined period of a length slightly less than one of said sweep intervals, said coincidence gate being disabled by said second state for said first predetermined period, and said second single-shot element being responsive to termination of said first predetermined period to provide a first of said sixth electrical signals during said sweep interval following said given sweep interval.
Claim 4
Dependent Claim
182 words
The combination defined in claim 2 and wherein said range memory means comprises a plurality of additional range memory circuits connected in parallel with said first range memory circuit between said coincidence gate means and said target alarm means; each of said additional memory circuits comprising a coincidence gate, a first single-shot element and a second single-shot element corresponding to those of said first range memory circuit; and the coincidence gates of said additional range memory circuits each being responsive to the state of the first single-shot element of the next preceding range memory circuit whereby successive ones of said fifth electrical signals in said given sweep interval trigger said first single-shot elements of successive ones of said range memory circuits to change from a first state to a second state for additional predetermined periods of lengths slightly less than said sweep intervals, and said second single-shot elements of said additional range memory circuits being responsive to terminations of the corresponding additional predetermined periods to provide successive ones of said sixth electrical signals during said sweep interval following said given sweep interval.
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) | 1980-10-31 | 1981-05-02 | 1981-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-31 | 1985-05-02 | 1985-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-31 | 1989-05-02 | 1989-11-01 | $7700.00 | Window Closed / Lapsed |