US3644882A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Marine acoustic velocity profiling
Assignee: Texas Instruments Inc
•
Filing: 1969-08-28
•
Granted: 1972-02-22
•
Expires: 1989-08-28
Abstract
Abstract A marine vessel streams a plurality of hydrophones while sequentially generating acoustic waves along a marine traverse at spaced-apart intervals to provide common depth point coverage of reflecting horizons within the water layer. The hydrophones receive reflections from the water layer to generate signals which are then recorded. Cross-correlations are taken of selected gates of the signals, the gates being related to one another in dependence upon the horizontal spacing between ones of the hydrophones. Acoustic velocity is the variable in the crosscorrelations. The cross-correlation products are summed to produce a composite velocity correlation function, the peak point of which provides an indication of the acoustic velocity of the underwater section through which the reflections of the acoustic waves travel. Arithmetic operations are performed on the acoustic velocities to provide a substantially real-time profile of the acoustic velocity of the intervals between the underwater reflecting horizons.
Inventors
- 👤 Kenneth E Burg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:28
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/28; G01V1/30; G01V1/303; G01N; G01N29/00; G01N29/04; G01N29/07; G01S; G01S1/00; G01S1/72; G01S15/00; G01S15/02; G01S15/06; G01S15/46
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
169 words
A system for determining the acoustic velocity profile of water and sediment masses comprising: a. means for sequentially generating acoustic waves along a marine traverse at spaced intervals sufficient to provide common depth point coverage of reflecting horizons, the generation of said acoustic waves being controlled by a digital computer, b. hydrophone means for receiving at a plurality of locations reflections from said acoustic waves to produce signals, said signals being selectively sampled by a digital computer such that signals from selected horizons caN be examined, c. means for cross-correlating selected ones of said signals where acoustic velocity is the correlation variable, d. means responsive to said cross-correlation for producing a composite velocity correlation function the peak positive points of which provide indications of the average velocities of said acoustic waves in the water and sediment masses through which said acoustic waves have traveled, and e. means responsive to said average velocities to determine the average sectional acoustic velocity profile of selected portions of said water and sediment masses.
Claim 2
Independent Claim
169 words
A system for determining the acoustic velocity profile of water and sediment masses comprising: a. means for sequentially generating acoustic waves along a marine traverse at spaced intervals sufficient to provide common depth point coverage of reflecting horizons, the generation of said acoustic waves being controlled by a digital computer, b. hydrophone means for receiving at a plurality of locations reflections from said acoustic waves to produce signals, said signals being selectively sampled by a digital computer such that signals from selected horizons caN be examined, c. means for cross-correlating selected ones of said signals where acoustic velocity is the correlation variable, d. means responsive to said cross-correlation for producing a composite velocity correlation function the peak positive points of which provide indications of the average velocities of said acoustic waves in the water and sediment masses through which said acoustic waves have traveled, and e. means responsive to said average velocities to determine the average sectional acoustic velocity profile of selected portions of said water and sediment masses.
Claim 3
Dependent Claim
21 words
The system of claim 5 and further comprising: a marine vessel streaming a plurality of hydrophones for reception of said reflections.
Claim 4
Dependent Claim
25 words
The system of claim 5 and further comprising: means for switching between selected ones of said hydrophones for reception of reflections from different selected depths.
Claim 5
Dependent Claim
36 words
The system of claim 1 wherein said signals are sampled digitally and said cross-correlation is accomplished digitally, the rate of said sampling being varied in dependence upon the depth of the underwater reflecting horizons being examined.
Claim 6
Independent Claim
135 words
A method of profiling the acoustic velocity of underwater masses comprising: a. sequentially generating acoustic waves along a marine traverse at spaced intervals sufficient to provide common depth point coverage of underwater reflecting horizons, b. receiving common depth point reflections from said acoustic waves to produce signals, c. digitally sampling said signals in dependence upon the underwater depth desired to be examined, d. cross-correlating ones of said signals where acoustic velocity is the correlation variable, e. producing from said cross-correlation composite velocity correlation functions the peak positive points of which provide indications of the average velocities of said acoustic waves in the water masses through which said acoustic waves have traveled, and f. operating on selected ones of said average velocities to determine the average sectional velocity of the intervals between selected underwater reflecting horizons.
Claim 7
Independent Claim
135 words
A method of profiling the acoustic velocity of underwater masses comprising: a. sequentially generating acoustic waves along a marine traverse at spaced intervals sufficient to provide common depth point coverage of underwater reflecting horizons, b. receiving common depth point reflections from said acoustic waves to produce signals, c. digitally sampling said signals in dependence upon the underwater depth desired to be examined, d. cross-correlating ones of said signals where acoustic velocity is the correlation variable, e. producing from said cross-correlation composite velocity correlation functions the peak positive points of which provide indications of the average velocities of said acoustic waves in the water masses through which said acoustic waves have traveled, and f. operating on selected ones of said average velocities to determine the average sectional velocity of the intervals between selected underwater reflecting horizons.
Claim 8
Dependent Claim
29 words
The method of claim 5 further including signal gates which are related to one another in dependence upon the horizontal spacing between the points of reception of said reflections.
Claim 9
Dependent Claim
31 words
The method of claim 5 wherein said step of operating on comprises: dividing the depth interval of reflecting horizons by the travel time of an acoustic wave through said depth interval.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |