US3836952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for rapid subsurface exploration
Assignee: United States Department of the Army
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Filing: 1972-03-03
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Granted: 1974-09-17
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Expires: 1992-03-03
Abstract
Abstract Exploring a selected zone of the earth to a shallow depth for a tunnel excavation, hollow, or other anomaly, without digging, which includes the use of a transmitter electro-seismic transducer and at least one receiver electro-seismic transducer for causing seismic energy to transmit from transmitter transducer to receiver transducer, through the ground in the selected zone, and examining for any unusual deviation in the phase angle difference between energy at the emitting transducer and energy at the receiving transducer as the span between transducers is displaced or as the span length is changed.
Inventors
- 👤 R Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:36
CPC Classifications
G; G01; G01V; G01V1/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
85 words
A method of detecting a subsurface shallow depth excavation comprising: coupling very narrow-band, constant-phase, continuous wave vibration energy to the surface of the earth for a selected time period and sensing seismic energy of the same frequency at the surface, the coupling and the sensing being at locations spaced by several meters, continuously shifting at least one of the locations, continuously metering and visibly registering only the phase angle between vibration energy coupled into the earth and the sensed seismic energy of the same frequency.
Claim 2
Independent Claim
85 words
A method of detecting a subsurface shallow depth excavation comprising: coupling very narrow-band, constant-phase, continuous wave vibration energy to the surface of the earth for a selected time period and sensing seismic energy of the same frequency at the surface, the coupling and the sensing being at locations spaced by several meters, continuously shifting at least one of the locations, continuously metering and visibly registering only the phase angle between vibration energy coupled into the earth and the sensed seismic energy of the same frequency.
Claim 3
Dependent Claim
20 words
A method of detecting a subsurface shallow depth excavation as defined in claim 1 which includes shifting the coupling location.
Claim 4
Dependent Claim
40 words
A method of detecting a subsurface shallow depth excavation as defined in claim 1 wherein said coupling to the earth and said sensing at the earth''s surface is at a constant distance apart, and shifting the two locations in train.
Claim 5
Dependent Claim
136 words
Apparatus for use in detecting a subsurface shallow depth excavation comprising: a vehicle; a pair of very-low-frequency, very-narrow-band electroseismic transducers, tuned to essentially the same very narrow band, mounted on said vehicle several meters apart for firm sliding engagement with the earth''s surface, for vibration energy transfer between the earth and each of said transducers, a signal generator and amplifier carried by said vehicle and coupled to one of said transducers, a phase metering means carried by said vehicle for providing continuously the phase angle difference between energy sensed by the other of said transducers and the energy at the input of said one of said transducers, and a recorder carried by said vehicle and coupled to the phase metering means for continuously registering the magnitude of phase angle difference provided by the phase metering means.
Claim 6
Dependent Claim
136 words
Apparatus for use in detecting a subsurface shallow depth excavation comprising: a vehicle; a pair of very-low-frequency, very-narrow-band electroseismic transducers, tuned to essentially the same very narrow band, mounted on said vehicle several meters apart for firm sliding engagement with the earth''s surface, for vibration energy transfer between the earth and each of said transducers, a signal generator and amplifier carried by said vehicle and coupled to one of said transducers, a phase metering means carried by said vehicle for providing continuously the phase angle difference between energy sensed by the other of said transducers and the energy at the input of said one of said transducers, and a recorder carried by said vehicle and coupled to the phase metering means for continuously registering the magnitude of phase angle difference provided by the phase metering means.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |