Patent DE2154338A1 successfully refreshed from Google Patents.
US3860759A
Expired / Lapsed
US
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Seismic system with data compression
Assignee: California Institute of Technology
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Filing: 1972-04-10
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Granted: 1975-01-14
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Expires: 1992-04-10
Abstract
Abstract A seismic data compression system is disclosed in which in the absence of a significant seismic event, a seismic signal which is filtered, rectified, and passed through a low-pass filter with a long time constant is sampled at a low rate to provide an indication of changes in background noise. When an event is detected, the system is switched to an event-sampling mode in which the envelope of the seismic signal and the number of zero crossing of the signal are sampled at a higher rate than that used in the absence of an event.
Inventors
- 👤 Wayne F Miller
- 👤 Francis E Lehner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:50
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; G; G01; G01V; G01V1/00; G01V1/24
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
167 words
In a seismic date compression system of the type to which a variable frequency and amplitude seismic signal is supplied as an input signal, the arrangement comprising: envelope detecting means responsive to said input signal for providing a variable amplitude direct-current output signal representing the envelope of said input signal, said envelope detecting means including means for rectifying said input signal; signal crossing detecting means responsive to said input signal for providing an output signal indicative of the number of crossings of said input signal with respect to a reference potential; event detecting means responsive to said rectified input signal for providing an event-indicating signal of a duration which is not less than a duration during which the amplitude of said rectified input signal exceeds by a preselected ratio the average amplitude of said rectified input signal over a preceding selected period; and means for sampling the output signals of said envelope detecting means and said signal crossing detecting means during the duration of said event-indicating signals.
Claim 2
Dependent Claim
167 words
In a seismic date compression system of the type to which a variable frequency and amplitude seismic signal is supplied as an input signal, the arrangement comprising: envelope detecting means responsive to said input signal for providing a variable amplitude direct-current output signal representing the envelope of said input signal, said envelope detecting means including means for rectifying said input signal; signal crossing detecting means responsive to said input signal for providing an output signal indicative of the number of crossings of said input signal with respect to a reference potential; event detecting means responsive to said rectified input signal for providing an event-indicating signal of a duration which is not less than a duration during which the amplitude of said rectified input signal exceeds by a preselected ratio the average amplitude of said rectified input signal over a preceding selected period; and means for sampling the output signals of said envelope detecting means and said signal crossing detecting means during the duration of said event-indicating signals.
Claim 3
Dependent Claim
85 words
The arrangement as recited in claim 1 wherein said event detecting means includes a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period in response to the rectified input signal, an attenuator responsive to the rectified input signal for attenuating said rectified input signal, and a comparator connected to said low-pass filter and said attenuator for providing an output whenever the attenuator output is not less than the output of said first filter.
Claim 4
Dependent Claim
61 words
The arrangement as recited in claim 2 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for providing Said event-indicating signal of a duration definable as tevent, where tevent ton + td, and wherein ton is the duration of the output of said comparator and td is a function of ton.
Claim 5
Dependent Claim
103 words
The arrangement as recited in claim 2 further including a rectifier for receiving said input signal and a second low-pass filter of a preselected time constant connected to the output of said rectifier for providing an output which is a function of the input signal amplitude over a period which is a function of the time constant of said second low-pass filter, and wherein said means for sampling sample any combination of the output of said second low-pass filter, the variable amplitude direct-current signal provided by said envelope detecting means and the signal provided by said signal crossing detecting means at selected rates.
Claim 6
Dependent Claim
64 words
The arrangement as recited in claim 4 wherein said means for sampling, in the absence of said event-indicating signal, sample the output of said rectifier and second filter at a first rate and in the presence of said event-indicating signal, sample the output signals of said envelope detecting means and said signal crossing detecting means at a second rate greater than said first rate.
Claim 7
Dependent Claim
39 words
The arrangement as recited in claim 5 further including variable filter means coupled to said rectifier and second filter and responsive to said input signal for filtering said input signal prior to supplying it to said rectifier second filter.
Claim 8
Dependent Claim
61 words
The arrangement as recited in claim 6 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for providing said event-indicating signal of a duration definable as tevent where tevent ton + td and wherein ton is the duration of the output of said comparator and td is a function of ton.
Claim 9
Dependent Claim
151 words
In a seismic data system of the type to which a variable frequency and amplitude seismic signal is supplied as an input signal, an arrangement comprising: event detecting means responsive to said input signal for providing an event-indicating signal of a duration which is a function of a duration during which the amplitude of said input signal exceeds by a preselected ratio the average amplitude of said input signal over a preceding selected duration, the event detecting means including a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period in response to the rectified input signal, an attenuator responsive to the rectified input signal for attenuating said rectified input signal, and a comparator connected to said low-pass filter and said attenuator for providing an output whenever the attenuator output is not less than the output of said first filter.
Claim 10
Dependent Claim
151 words
In a seismic data system of the type to which a variable frequency and amplitude seismic signal is supplied as an input signal, an arrangement comprising: event detecting means responsive to said input signal for providing an event-indicating signal of a duration which is a function of a duration during which the amplitude of said input signal exceeds by a preselected ratio the average amplitude of said input signal over a preceding selected duration, the event detecting means including a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period in response to the rectified input signal, an attenuator responsive to the rectified input signal for attenuating said rectified input signal, and a comparator connected to said low-pass filter and said attenuator for providing an output whenever the attenuator output is not less than the output of said first filter.
Claim 11
Dependent Claim
58 words
The arrangement as recited in claim 8 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for providing said event-indicating signal of a duration which is longer than the duration of the output of said comparator by a factor which is a function of the comparator output duration.
Claim 12
Dependent Claim
165 words
In a data compression system of the type to which a variable frequency and amplitude signal is supplied as an input signal, the arrangement comprising: envelope detecting means responsive to said input signal for providing a variable amplitude direct-current output signal, representing the envelope of said input signal, said envelope detecting means including means for rectifying said input signal; signal crossing detecting means responsive to said input signal for providing an output signal indicative of the number of crossings of said input signal with respect to a reference potential; event detecting means responsive to said rectified input signal for providing an event-indicating signal of a duration which iS not less than a duration during which the amplitude of said rectified input signal exceeds by a preselected ratio the average amplitude of said rectified input signal over a preceding selected period; and means for sampling the output signals of said envelope detecting means and said signal crossing detecting means during the duration of said event-indicating signals.
Claim 13
Dependent Claim
165 words
In a data compression system of the type to which a variable frequency and amplitude signal is supplied as an input signal, the arrangement comprising: envelope detecting means responsive to said input signal for providing a variable amplitude direct-current output signal, representing the envelope of said input signal, said envelope detecting means including means for rectifying said input signal; signal crossing detecting means responsive to said input signal for providing an output signal indicative of the number of crossings of said input signal with respect to a reference potential; event detecting means responsive to said rectified input signal for providing an event-indicating signal of a duration which iS not less than a duration during which the amplitude of said rectified input signal exceeds by a preselected ratio the average amplitude of said rectified input signal over a preceding selected period; and means for sampling the output signals of said envelope detecting means and said signal crossing detecting means during the duration of said event-indicating signals.
Claim 14
Dependent Claim
85 words
The arrangement as recited in claim 10 wherein said event detecting means includes a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period in response to the rectified input signal, an attenuator responsive to the rectified input signal for attenuating said rectified input signal, and a comparator connected to said low-pass filter and said attenuator for providing an ouput whenever the attenuator output is not less than the output of said first filter.
Claim 15
Dependent Claim
61 words
The arrangement as recited in claim 11 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for providing said event-indicating signal of a duration definable as tevent, where tevent ton + td, and wherein ton is the duration of the output of said comparator and td is a function of ton.
Claim 16
Dependent Claim
96 words
The arrangement as recited in claim 11 further including a rectifier for receiving said input signal and a second low-pass filter of a preselected time constant connected to the output of said rectifier for providing an output which is a function of the input signal amplitude over a period controlled by said preselected time constant, and wherein said means for sampling sample any combination of the output of said second low-pass filter, the variable amplitude direct-current signal provided by said envelope detecting means and the signal provided by said signal crossing detecting means at selected rates.
Claim 17
Dependent Claim
62 words
The arrangement as recited in claim 13 wherein said means for sampling, in the absence of said event-indicating signal, sample the output of said second filter at a first rate and in the presence of said event-indicating signal, sample the output signals of said envelope detecting means and said signal crossing detecting means at a second rate greater than said first rate.
Claim 18
Dependent Claim
23 words
The arrangement as recited in claim 14 further including variable filter for filtering said input signal prior to supplying it to said rectifier.
Claim 19
Dependent Claim
61 words
The arrangement as recited in claim 15 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for providing said event-indicating signal of a duration definable as tevent where tevent ton + td and wherein ton is the duration of the output of said comparator and td is a function of ton.
Claim 20
Dependent Claim
143 words
In a data system of the type to which a variable frequency and amplitude signal is supplied as an input signal, an arrangement comprising: event detecting means responsive to said input signal for providing an event-indicating signal of a duration which is a function of a duration during which the amplitude of said input signal exceeds the average amplitude of said input signal by a preselected ratio over a preceding selected duration, said event detecting means including a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period, an attenuator responsive to the input signal for attenuating said input signal, by a preselected factor and a comparator connected to said low-pass filter and said attenuator for providing an output whenever the attenuator output is not less than the output of said filter.
Claim 21
Dependent Claim
143 words
In a data system of the type to which a variable frequency and amplitude signal is supplied as an input signal, an arrangement comprising: event detecting means responsive to said input signal for providing an event-indicating signal of a duration which is a function of a duration during which the amplitude of said input signal exceeds the average amplitude of said input signal by a preselected ratio over a preceding selected duration, said event detecting means including a first low-pass filter for providing an output indicative of the average amplitude of said input signal over said preceding selected period, an attenuator responsive to the input signal for attenuating said input signal, by a preselected factor and a comparator connected to said low-pass filter and said attenuator for providing an output whenever the attenuator output is not less than the output of said filter.
Claim 22
Dependent Claim
58 words
The arrangement as recited in claim 17 wherein said event detecting means further includes a time dependent delay unit responsive to the output of said comparator for pRoviding said event-indicating signal of a duration which is longer than the duration of the output of said comparator by a factor which is a function of the comparator output duration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-13 | 1978-07-15 | 1979-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-13 | 1982-07-15 | 1983-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-13 | 1986-07-15 | 1987-01-14 | $7700.00 | Window Closed / Lapsed |