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US4680741A
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Method and apparatus for seismic exploration using non-linear sweeps
Assignee: Ion Geophysical Corp
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Filing: 1986-09-29
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Granted: 1987-07-14
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Expires: 2006-09-29
Abstract
Abstract A method and apparatus for generating a nonlinear sweep signal to be supplied to a seismic vibrator. A seismic sweep time is determined and is divided into a plurality of preselected time intervals. The rate of change of the frequency is determined for each of these time intervals to generate an output signal of a desired shape. The rate of change of the frequency for each time interval is calculated in response to the starting frequency of the sweep, the range of the sweep, the sweep time, and the desired shape of the output signal. The rate of change is supplied to a frequency generator which generates a signal to be supplied to the vibrator.
Inventors
- 👤 C. Ernest Wales
- 👤 Mitchell F. Peterson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 20:22
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/02; G01V1/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
130 words
A method of generating one of a plurality of possible nonlinear sweep signals of predetermined time and shape and at the output of a sweep generator utilized to operate a seismic vibrator, comprising the steps of: (a) dividing the sweep time of the output signal into a plurality of time intervals; (b) calculating the rate of change of the frequency of the output sweep signal for each of said time intervals to realize said predetermined shape, said calculation in response to the range of the sweep, the sweep time, the starting frequency and the predetermined shape; and (c) Using each of said values calculated in step (b) to change the rate of change of frequency of the sweep signal for each of said preselected time intervals within said sweep time.
Claim 2
Independent Claim
130 words
A method of generating one of a plurality of possible nonlinear sweep signals of predetermined time and shape and at the output of a sweep generator utilized to operate a seismic vibrator, comprising the steps of: (a) dividing the sweep time of the output signal into a plurality of time intervals; (b) calculating the rate of change of the frequency of the output sweep signal for each of said time intervals to realize said predetermined shape, said calculation in response to the range of the sweep, the sweep time, the starting frequency and the predetermined shape; and (c) Using each of said values calculated in step (b) to change the rate of change of frequency of the sweep signal for each of said preselected time intervals within said sweep time.
Claim 3
Dependent Claim
133 words
Apparatus for producing one of a plurality of nonlinear sweep signals for operating a seismic vibrator, comprising; means for generating signals representative of the rate of change of frequency of the sweep signal for each of a plurality of time intervals of the sweep time, said rate of change determined for each of said time intervals in response to the starting frequency of the sweep, the range of the sweep, the sweep time and the desired shape of the sweep; means for storing said rate of change signals in a memory; means for commencing the sweep signal at the starting frequency; and means for changing the frequency of the sweep signal during each said individual time interval of the sweep at the rate stored in said memory for each said individual time interval.
Claim 4
Dependent Claim
133 words
Apparatus for producing one of a plurality of nonlinear sweep signals for operating a seismic vibrator, comprising; means for generating signals representative of the rate of change of frequency of the sweep signal for each of a plurality of time intervals of the sweep time, said rate of change determined for each of said time intervals in response to the starting frequency of the sweep, the range of the sweep, the sweep time and the desired shape of the sweep; means for storing said rate of change signals in a memory; means for commencing the sweep signal at the starting frequency; and means for changing the frequency of the sweep signal during each said individual time interval of the sweep at the rate stored in said memory for each said individual time interval.
References Cited (Backward Citations)
US3739374A
Cited
US4004267A
Cited
US3815704A
Cited
US3886493A
Cited
US4168485A
Cited
US4293935A
Cited
US4326262A
Cited
US4248324A
Cited
US4493067A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |