US5025423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enhanced bottom sonar system
Assignee: Nokia Bell Labs
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Filing: 1989-12-21
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Granted: 1991-06-18
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Expires: 2009-12-21
Abstract
Abstract Buried ocean cable is irradiated with a suitable sonar signal, and in response emits distinct characteristic "signature" backscatter signals. The "signature" signals are distinct for specific individual constructions of cable, and therefore assist in determining the identity of a buried object without having to dig it up. Search apparatus launches the unique sonar signal toward the buried cable, with a predetermined beamwidth, attack angle, cross-section, and signal character. The signal consists of a succession of bursts of different frequencies, separated by a step function, for example, and separated by silent periods. The signal is repeated as the search vehicle travels a predetermined direction with respect to the estimated cable orientation. The backscatter signals are received by the sonar apparatus for analysis by digital comparison to a data library of known signal patterns, or for display on an operator's monitor.
Inventors
- 👤 Ronald L. Earp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:15
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/52; G01S7/539; G01S15/00; G01S15/003; G01S15/88; G01S15/89; G02; G02B; G02B6/00; G02B6/46; G02B6/50; G02B6/506
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
111 words
A system for identifying objects, comprising: means for transmitting toward a target a first signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy created by each successive individual frequency burst of said first signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular object when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 2
Independent Claim
111 words
A system for identifying objects, comprising: means for transmitting toward a target a first signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy created by each successive individual frequency burst of said first signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular object when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 3
Dependent Claim
16 words
The system of claim 1, further comprising: means for transmitting a succession of said first signals.
Claim 4
Dependent Claim
34 words
The system of claim 2, further comprising: means for transmitting each successive burst of each first signal for a long enough duration to intercept and interfere with said backscatter signals from the same burst.
Claim 5
Dependent Claim
19 words
The system of claim 3, wherein said transmitting means comprises means for separating individual bursts with a silent period.
Claim 6
Independent Claim
129 words
A system for identifying objects disposed on or within the floor of a body of water, comprising: means for transmitting toward a target a first sonar signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy created by each successive individual frequency burst of said first sonar signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular object on or within said floor when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 7
Independent Claim
129 words
A system for identifying objects disposed on or within the floor of a body of water, comprising: means for transmitting toward a target a first sonar signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy created by each successive individual frequency burst of said first sonar signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular object on or within said floor when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 8
Dependent Claim
17 words
The system of claim 5, further comprising: means for transmitting a succession of said first sonar signals.
Claim 9
Dependent Claim
36 words
The system of claim 6, further comprising: means for transmitting each successive burst of each said first sonar signal for a long enough duration to intercept and interfere with said backscatter signals from the same burst.
Claim 10
Dependent Claim
19 words
The system of claim 7, wherein said transmitting means comprises means for separating individual bursts with a silent period.
Claim 11
Independent Claim
135 words
A system for identifying a cable disposed on or within the floor of a body of water, comprising: means for transmitting toward said cable a first sonar signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy from said cable created by each successive individual frequency burst of said first sonar signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular structure of cable on or within said floor when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 12
Independent Claim
135 words
A system for identifying a cable disposed on or within the floor of a body of water, comprising: means for transmitting toward said cable a first sonar signal comprising a succession of bursts of selected different frequencies; means for receiving the target backscatter energy from said cable created by each successive individual frequency burst of said first sonar signal; means for collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular structure of cable on or within said floor when impinged by said first signal; and means for determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 13
Dependent Claim
20 words
The system of claim 9, further comprising: means for transmitting a succession of said first sonar signals onto said cable.
Claim 14
Dependent Claim
36 words
The system of claim 10, further comprising: means for transmitting each successive burst of each said first sonar signal for a long enough duration to intercept and interfere with said backscatter signals from the same burst.
Claim 15
Dependent Claim
19 words
The system of claim 11, wherein said transmitting means comprises means for separating individual bursts with a silent period.
Claim 16
Dependent Claim
38 words
The system of claim 12, wherein said library comprises data point sets representative of rhe backscatter energy of a particular structure of cable on or within said floor when impinged by said first signal at predetermined grazing angles.
Claim 17
Dependent Claim
25 words
The system of claim 13, wherein said transmitting means further comprises means for controlling the beamwidth and the beam cross-section of said first sonar signal.
Claim 18
Dependent Claim
27 words
The system of claim 14, wherein said transmitting means further comprises means for controlling the attack angle of said first sonar signal with respect to said floor.
Claim 19
Dependent Claim
40 words
The system of claim 15, wherein said library further comprises data point sets representative of the backscatter energy of a particular structure of cable on or within said floor when impinged by said first sonar signal at predetermined attack angles.
Claim 20
Dependent Claim
25 words
The system of claim 16, wherein said succession of separate signal bursts are contained in a range of substantially from 5,000 Hz. to 20,000 Hz.
Claim 21
Dependent Claim
25 words
The system of claim 17, wherein said succession of frequency bursts in each said first signal are separated by a predetermined selected positive step function.
Claim 22
Dependent Claim
25 words
The system of claim 18, wherein the duration of each burst is substantially 5 milliseconds; and the time separation between bursts is substantially 50 milliseconds.
Claim 23
Dependent Claim
26 words
The system of claim 19, wherein the cross-section of said search signal is an ellipsoid with the major axis thereof oriented to sweep across said cable.
Claim 24
Dependent Claim
18 words
The system of claim 20, further comprising; means for visually presenting said collected data points on a monitor.
Claim 25
Dependent Claim
25 words
The system of claim 21, further comprising: means including a digital signal processor for comparing said collected data points with said representative data point sets.
Claim 26
Independent Claim
128 words
A method for identifying a cable disposed on or within the floor of a body of water, comprising: transmitting toward said cable a first sonar signal comprising a succession of bursts of selected different frequencies; receiving the target backscatter energy from said cable created by each successive individual frequency burst of said first sonar signal; collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; providing a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular structure of cable on or within said floor when impinged by said first signal; and determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 27
Independent Claim
128 words
A method for identifying a cable disposed on or within the floor of a body of water, comprising: transmitting toward said cable a first sonar signal comprising a succession of bursts of selected different frequencies; receiving the target backscatter energy from said cable created by each successive individual frequency burst of said first sonar signal; collecting as data points over the range of frequencies used, each backscatter signal amplitude value and the associated burst frequency; providing a reference library of data point sets, each set predetermined to be representative of the backscatter energy of a particular structure of cable on or within said floor when impinged by said first signal; and determining which set of predetermined reference data points is most closely matched to said collected data points.
Claim 28
Dependent Claim
55 words
The method in accordance with claim 23, wherein said transmission step further comprises: generating a sequence of tone bursts in which each burst is an incremental step higher in frequency than the preceding burst, and each burst is separated in time from its predecessor, for a predetermined number of steps, and then repeating the sequence.
Claim 29
Dependent Claim
26 words
The method in accordance with claim 24, comprising the further step of setting the sampling rate to a predetermined value depending on the highest frequency transmitted.
Claim 30
Dependent Claim
18 words
The method of claim 25, comprising the further step of disabling said receiving step during said transmitting step.
References Cited (Backward Citations)
US4870623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-17 | 1994-12-17 | 1995-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-17 | 1998-12-17 | 1999-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-17 | 2002-12-17 | 2003-06-18 | $7700.00 | Window Closed / Lapsed |