US3636435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of electromagnetic prospecting by measuring relative grandient of a resultant electromagnetic field
Assignee: Scintrex Ltd
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Filing: 1969-06-20
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Granted: 1972-01-18
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Expires: 1989-06-20
Abstract
Abstract This invention relates to a method of electromagnetic prospecting wherein a pair of detecting coils are rigidly mounted on a common support on a moving vehicle for the purpose of measuring the relative gradient of the resultant electromagnetic field. Rigidly supporting the coils on the moving vehicle renders them insensitive to misorientation of the detectors and this is of special advantage in airborne electromagnetic survey work.
Inventors
- 👤 Harold O Seigel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:04
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/15; G01V3/165
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
The method of electromagnetic prospecting including the steps of inducing into a subsurface area to be explored a primary electromagnetic field from a fixed energizing source located at a first distance therefrom; measuring by vehicle-carried similarly oriented rigidly spaced detecting means the relative gradient of a characteristic of a component of the electromagnetic field at a second distance above said subsurface area while maintaining said second distance small as compared with said first distance whereby said relative gradient will be dominated by effects attributable to the presence of conductors in said area, said detecting means being at least a distance of a mile from said energizing source of said primary field; and repeating said measurements while moving said vehicle over said subsurface area to be explored.
Claim 2
Independent Claim
126 words
The method of electromagnetic prospecting including the steps of inducing into a subsurface area to be explored a primary electromagnetic field from a fixed energizing source located at a first distance therefrom; measuring by vehicle-carried similarly oriented rigidly spaced detecting means the relative gradient of a characteristic of a component of the electromagnetic field at a second distance above said subsurface area while maintaining said second distance small as compared with said first distance whereby said relative gradient will be dominated by effects attributable to the presence of conductors in said area, said detecting means being at least a distance of a mile from said energizing source of said primary field; and repeating said measurements while moving said vehicle over said subsurface area to be explored.
Claim 3
Dependent Claim
21 words
A method of electromagnetic prospecting as claimed in claim 1 in which said characteristic of the electromagnetic field is relative amplitude.
Claim 4
Dependent Claim
20 words
A method of electromagnetic prospecting as claimed in claim 1 in which said characteristic of the electromagnetic field is phase.
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) | 1975-01-17 | 1975-07-19 | 1976-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-17 | 1979-07-19 | 1980-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-17 | 1983-07-19 | 1984-01-18 | $7700.00 | Window Closed / Lapsed |