Patent US4825165A successfully refreshed from Google Patents.
US4825165A
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Method and apparatus for detecting a transient phenomenon by monitoring variations of an alternating component of a vertical current emanating from the earth's surface
Assignee: Individual
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Filing: 1987-04-13
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Granted: 1989-04-25
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Expires: 2007-04-13
Abstract
Abstract A method and apparatus for locating and evaluating surface and subsurface anomalies by detecting, monitoring or measuring transient or local variations respectively which occur in an alternating component of a vertical current having a frequency characteristic which emanates from the earth'surface in the region being monitored or measured. For locating fixed anomalies, local variations which occur in the amplitude, frequency and frequency modulation of the alternating component of the vertical current are measured. For detecting the passage of moving or transient anomalies, a stationary detector is positioned to detect any change in the vertical alternating current leakage in the vicinity of the detector which is caused by a moving or transient anomaly such as a submerged submarine, seismic activity, or sustained severe wheather. For accuracy enhancement and redundancy, simultaneous measurements of the signal strength in multiple frequency bands may be used.
Inventors
- 👤 Ronald L. Helms
- 👤 Claude V. Swanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:31
CPC Classifications
G; G01; G01V; G01V9/00; G01V3/00; G01V3/08
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
100 words
A method of monitoring a transient phenomenon occurring on or beneath the surface of the earth and in the vicinity of a location of interest, comprising the steps of: positioning a detector at said location; measuring with said detector, an alternating component of a generally vertical current having a frequency characteristic which emanates from the earth in the vicinity of said location; monitoring said alternating component of the generally vertical current emanating from the earth for variations indicative of the occurrence of said phenomenon; correlating said variation with data indicative of said phenomenon to determine the occurrence of said phenomenon.
Claim 2
Independent Claim
100 words
A method of monitoring a transient phenomenon occurring on or beneath the surface of the earth and in the vicinity of a location of interest, comprising the steps of: positioning a detector at said location; measuring with said detector, an alternating component of a generally vertical current having a frequency characteristic which emanates from the earth in the vicinity of said location; monitoring said alternating component of the generally vertical current emanating from the earth for variations indicative of the occurrence of said phenomenon; correlating said variation with data indicative of said phenomenon to determine the occurrence of said phenomenon.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said transient phenomena comprises a vessel passing in the vicinity of said location.
Claim 4
Dependent Claim
12 words
The method of claim 2 whereas said vessel comprises a submerged submarine.
Claim 5
Dependent Claim
14 words
The method of claim 1 wherein said transient phenomenon comprises a subsurface seismic event.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said transient phenomenon comprises a weather disturbance.
Claim 7
Dependent Claim
28 words
The method of claim 1 wherein the step of measuring further comprises measuring variations which occur in a frequency of said generally vertical current emanating from the earth.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein the step of measuring further measuring variations which occur in an amplitude of said generally vertical current emanating from the earth.
Claim 9
Dependent Claim
29 words
The method of claim 1 wherein the step of measuring further comprises measuring local variations which occur in an amplitude of said generally vertical current emanating from the earth.
Claim 10
Dependent Claim
29 words
The method of claim 8 wherein the step of measuring further comprises measuring variations which occur in a frequency modulation of said generally vertical current emanating from the earth.
Claim 11
Dependent Claim
30 words
The method of claim 1 wherein the step of measuring further comprises measuring local variations which occur in a frequency modulation of said generally vertical current emanating from the earth.
Claim 12
Dependent Claim
30 words
The method of claim 10 wherein the step of measuring further comprises measuring local variations which occur in said frequency characteristic of said generally vertical current emanating from the earth.
Claim 13
Dependent Claim
32 words
The method of claim 11 wherein the step of measuring further comprises the step of measuring local variations which occur in an amplitude of said generally vertical current emanating from the earth.
Claim 14
Dependent Claim
30 words
The method of claim 1 further comprising the step of monitoring solar activity and evaluating the measured alternating component of the generally vertical current in accordance with said solar activity.
Claim 15
Dependent Claim
30 words
The method of claim 12 further comprising the step of monitoring solar activity and evaluating the measured alternating component of the generally vertical current in accordance with said solar activity.
Claim 16
Independent Claim
68 words
A method of monitoring a transient phenomenon comprising: receiving, with an antenna, signals indicative of an alternating component of a generally vertical current emanating from the earth; filtering said signals into at least two frequency bands; time averaging the signals within each of said at least two frequency bands; processing said time-averaged signals with data corresponding to said phenomenon to thereby indicate the occurrence of said transient phenomenon.
Claim 17
Independent Claim
68 words
A method of monitoring a transient phenomenon comprising: receiving, with an antenna, signals indicative of an alternating component of a generally vertical current emanating from the earth; filtering said signals into at least two frequency bands; time averaging the signals within each of said at least two frequency bands; processing said time-averaged signals with data corresponding to said phenomenon to thereby indicate the occurrence of said transient phenomenon.
Claim 18
Dependent Claim
35 words
The method of claim 15 further comprising the step of measuring auxiliary environmental phenomena, and wherein the step of processing further comprises evaluating the time averaged signals in view of the measured auxiliary environmental phenomena.
Claim 19
Dependent Claim
29 words
The method of claim 15 further comprising the step of amplifying said signals indicative of the alternating component of the generally vertical current prior to the step of filtering.
Claim 20
Dependent Claim
34 words
The method of claim 15 wherein said step of time averaging further comprises the steps of rectifying and averaging over a time period T i , the signals in each of said frequency bands.
Claim 21
Dependent Claim
92 words
The method of claim 18 wherein the time period T i is less than a time period over which said transient phenomenon occurs, and said step of processing further comprises averaging said rectified and averaged signals in each frequency band over a period t i , where t i is greater than T i , and then comparing the signals time averaged over T i with the signals time averaged over t i wherein t i is at least on the order of the time period over which said transient phenomenon occurs.
Claim 22
Dependent Claim
52 words
The method of claim 19 wherein the step of processing further comprises outputting a signal from each frequency band whenever the signal time averaged over T i is greater than the signal time averaged over t i by more than a threshold value, and combining output signals from said frequency bands together.
Claim 23
Dependent Claim
37 words
The method of claim 20 further comprising the step of measuring auxiliary environmental phenomena, and wherein the step of processing further comprises combining a signal representative of the measured auxiliary environmental variables with the time averaged signals.
Claim 24
Dependent Claim
35 words
The method of claim 18 wherein said step of processing further comprises converting the rectified and averaged signals into digital signals and processing said signals in a digital computer programmed to identify the transient phenomenon.
Claim 25
Independent Claim
96 words
An apparatus for detecting the occurrence of a transient phenomenon comprising: means for receiving a signal indicative of an alternating component of a generally vertical current emanating from the earth; means connected to said receiving means for filtering said signal into a plurality of signals corresponding to a plurality of frequency bands; means connected to said filtering means for time averaging the signals in each of said frequency bands; means connected to said time averaging means for processing the time-averaged signals with data corresponding to said phenomenon to thereby indicate the occurrence of the transient phenomenon.
Claim 26
Independent Claim
96 words
An apparatus for detecting the occurrence of a transient phenomenon comprising: means for receiving a signal indicative of an alternating component of a generally vertical current emanating from the earth; means connected to said receiving means for filtering said signal into a plurality of signals corresponding to a plurality of frequency bands; means connected to said filtering means for time averaging the signals in each of said frequency bands; means connected to said time averaging means for processing the time-averaged signals with data corresponding to said phenomenon to thereby indicate the occurrence of the transient phenomenon.
Claim 27
Dependent Claim
12 words
The apparatus of claim 23 wherein said receiving means comprises an antenna.
Claim 28
Dependent Claim
16 words
The apparatus of claim 24 wherein said receiving means further comprises means for amplifying said signal.
Claim 29
Dependent Claim
22 words
The apparatus of claim 23 wherein said filtering means comprises a plurality of band-pass filters corresponding to said plurality of frequency bands.
Claim 30
Dependent Claim
26 words
The apparatus of claim 23 further comprising a corrective signal generator for measuring auxiliary environmental variables and generating a corrective signal therefrom to said processing means.
Claim 31
Dependent Claim
50 words
The apparatus of claim 23 wherein said time averaging means comprises a rectifier means for rectifying and time averaging over an averaging period T i , each of said plurality of signals, wherein the time period T i is less than a time period over which the transient phenomena occurs.
Claim 32
Dependent Claim
80 words
The apparatus of claim 28 wherein the processing means further comprises means for averaging said rectified and time averaged signals over an averaging period t i , where t i is greater than T i and means for comparing the signals time averaged over the period T i with the signals time averaged over the period t i , wherein the period t i is at least on the order of the time period over which said transient phenomenon occurs.
Claim 33
Dependent Claim
58 words
The apparatus of claim 29 wherein said comparing means produces an output signal from each frequency band whenever the signal time averaged over T i is greater than the signal time averaged over t i by more than a threshold value, and said processing means further comprises means for combining the output signals from said frequency bands together.
Claim 34
Dependent Claim
27 words
The apparatus of claim 30 further comprising a corrective signal generator operable to monitor auxiliary variables and to generate therefrom a corrective signal to said combining means.
Claim 35
Dependent Claim
46 words
The apparatus of claim 28 wherein said processing means further comprises an analog to digital converter connected to rectifier means, and a digital computer connected to receive input signals from said analog to digital converter and programmed to identify a transient phenomenon from said input signals.
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) | 1992-04-24 | 1992-10-24 | 1993-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-24 | 1996-10-24 | 1997-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-24 | 2000-10-24 | 2001-04-25 | $7700.00 | Window Closed / Lapsed |