US3738164A
Expired / Lapsed
US
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Measurements pertaining to ocean currents by geomagnetic induction
Assignee: Woods Hole Oceanographic Institution
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Filing: 1971-05-21
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Granted: 1973-06-12
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Expires: 1991-05-21
Abstract
Abstract The variations in the magnitudes and the directions of horizontal ocean currents are measured as a function of depth. A measuring probe falls to a predetermined depth and is carried by the current. The probe has a circuit within which a varying electric potential is induced by the earth''s magnetic field. This potential is a function of the velocity of the probe and the velocity of the sea water. Data derived from this potential and the related sea water temperature and pressure are used to derive detailed vertical characteristic profiles of ocean currents.
Inventors
- 👤 T Sanford
- 👤 R Dreyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:29
CPC Classifications
G; G01; G01C; G01C13/00; G01C13/002; G01C13/006
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
110 words
A method of measuring the velocity characteristics of an ocean current in which a horizontal electric field exists, said field being substantially proportional to the average horizontal velocity of said ocean current between the surface and the bottom along a line parallel to the vertical component of the earth''s magnetic field, including the steps of generating an electric current in a detector located at a given depth in said ocean current, said current resulting from the interaction with said vertical component of the earth''s magnetic field of the difference between said average horizontal velocity and the horizontal velocity of said detector, and recording a value proportional to said electric current.
Claim 2
Independent Claim
110 words
A method of measuring the velocity characteristics of an ocean current in which a horizontal electric field exists, said field being substantially proportional to the average horizontal velocity of said ocean current between the surface and the bottom along a line parallel to the vertical component of the earth''s magnetic field, including the steps of generating an electric current in a detector located at a given depth in said ocean current, said current resulting from the interaction with said vertical component of the earth''s magnetic field of the difference between said average horizontal velocity and the horizontal velocity of said detector, and recording a value proportional to said electric current.
Claim 3
Dependent Claim
31 words
The method according to claim 1, in which said electric current is generated by magnetic transformer coupling to the electric current flowing in the ocean at the location of said detector.
Claim 4
Dependent Claim
61 words
The method according to claim 1, in which said electric current is generated by electromagnetic induction along a line having a horizontal component of length, said line being moved successively to a plurality of positions spAced along a descending path in said ocean current and moving at each said position substantially at the same horizontal velocity as the contiguous ocean current.
Claim 5
Dependent Claim
13 words
The method according to claim 3, in which said line is substantially horizontal.
Claim 6
Dependent Claim
22 words
The method according to claim 3, in which the line is rotated at a substantially constant frequency about a substantially vertical axis.
Claim 7
Dependent Claim
19 words
The method according to claim 5, in which said substantially vertical axis intersects said line substantially at its midpoint.
Claim 8
Dependent Claim
55 words
The method according to claim 3, including the steps of generating an electric correction potential equal to that induced along said line as a result of the vertial component of velocity of said detector through the horizontal component of the earth''s magnetic field, and applying said correction potential to cancel that induced along said line.
Claim 9
Dependent Claim
23 words
The method according to claim 5, including the step of passing the electric current through a band pass filter tuned to said frequency.
Claim 10
Dependent Claim
35 words
The method according to claim 3, in which the electric current is periodically alternated, and including the step of passing the electric current through a band pass filter tuned to the frequency of said alternation.
Claim 11
Dependent Claim
74 words
A probe for measuring velocity variations with depth in ocean currents, said probe having, in combination, means to cause the probe to descend toward the bottom, and means for generating in the probe an electric current resulting from the interaction with the vertical component of the earth''s magnetic field of the difference between the average horizontal velocity of said ocean current between the surface and the bottom and the horizontal velocity of said probe.
Claim 12
Dependent Claim
74 words
A probe for measuring velocity variations with depth in ocean currents, said probe having, in combination, means to cause the probe to descend toward the bottom, and means for generating in the probe an electric current resulting from the interaction with the vertical component of the earth''s magnetic field of the difference between the average horizontal velocity of said ocean current between the surface and the bottom and the horizontal velocity of said probe.
Claim 13
Dependent Claim
28 words
A probe according to claim 10 which is buoyant and includes releaseable weight means to cause it to descend toward the bottom and to return toward the surface.
Claim 14
Dependent Claim
26 words
A probe according to claim 10, in which the generating means include a toroidal coil and means to maintain a substantially vertical orientation of its plane.
Claim 15
Dependent Claim
28 words
A probe according to claim 10, including fin means to cause it to rotate at a substantially constant frequency about a substantially vertical axis as said probe descends.
Claim 16
Dependent Claim
22 words
Apparatus acording to claim 13, including a band pass filter in connection with said means for generating and tuned to said frequency.
Claim 17
Dependent Claim
130 words
Apparatus for measuring velocity variation with depth in ocean currents including, in combination, a buoyant probe having longitudinally conductive laterally insulated arm means, said arm means having an end thereof adapted for electrical connection with contiguous sea water, means to detect an electric potential induced in said arm means, said potential resulting from the interaction with the vertical component of the earth''s magnetic field of the difference between the average horizontal velocity of said ocean current between the surface and the bottom and the horizontal velocity of said probe, and means operable to overcome the buoyancy of said probe to cause it to descend freely when released in said water, said probe being adapted to orient said arm means along a line having a horizontal component as said probe descends.
Claim 18
Dependent Claim
130 words
Apparatus for measuring velocity variation with depth in ocean currents including, in combination, a buoyant probe having longitudinally conductive laterally insulated arm means, said arm means having an end thereof adapted for electrical connection with contiguous sea water, means to detect an electric potential induced in said arm means, said potential resulting from the interaction with the vertical component of the earth''s magnetic field of the difference between the average horizontal velocity of said ocean current between the surface and the bottom and the horizontal velocity of said probe, and means operable to overcome the buoyancy of said probe to cause it to descend freely when released in said water, said probe being adapted to orient said arm means along a line having a horizontal component as said probe descends.
Claim 19
Dependent Claim
23 words
Apparatus according to claim 15, in which said probe is adapted to orient said arm means substantially horizontally as said probe is falling.
Claim 20
Dependent Claim
31 words
Apparatus according to claim 15, in which the probe has fin means to cause it to rotate at a substantially constant frequency about a substantially vertical axis as said probe descends.
Claim 21
Dependent Claim
18 words
Apparatus according to claim 17, in which said substantially vertical axis intersects said line at substantially its midpoint.
Claim 22
Dependent Claim
31 words
Apparatus according to claim 15, in which the probe has a correction coil formed about an axis substantially parallel to said arm means and in connection with said means to detect.
Claim 23
Dependent Claim
18 words
Apparatus according to claim 19, in which said correction coil is in series connection with said arm means.
Claim 24
Dependent Claim
22 words
Apparatus according to claim 17, including a band pass filter in connection with said means to detect and tuned to said frequency.
Claim 25
Dependent Claim
16 words
Apparatus according to claim 15, including a sonic transmitter in connection with said means to detect.
Claim 26
Dependent Claim
29 words
Apparatus according to claim 22, including water pressure sensing means connected with said transmitter, said transmitter being adapted to transmit signals independently measuring said electric potential and water pressure.
Claim 27
Dependent Claim
41 words
Apparatus according to claim 15, in which said arm means include a pair of arms each having one end adapted for electrical connection with contiguous sea water and an electrode at its opposite end for connection with said means to detect.
Claim 28
Dependent Claim
53 words
Apparatus according to claim 24, in which the arms are of substantially equal length, the probe having fin means to cause it to rotate as said probe descends at a substantially constant frequency about a substantially vertical axis midway between the ends of said arms adapted for electrical connection with contiguous sea water.
Claim 29
Dependent Claim
32 words
Apparatus according to claim 24, in which each of said arms comprises an insulating tube filled with an electrolyte and having an outwardly exposed conductive plug having inner contact with said electrolyte.
Claim 30
Dependent Claim
17 words
Apparatus according to claim 26, in which said electrolyte is sea water and said plug is porous.
Claim 31
Dependent Claim
29 words
Apparatus according to claim 27, having an insulating plate, each of said arms being closed at its said opposite end by said plate and having its electrode mounted thereon.
Claim 32
Dependent Claim
41 words
The method according to claim 1, in which said electric current is generated by electromagnetic induction of a potential between two electrodes respectively connected with the ambient ocean water at the ends of a line having a horizontal component of length.
Claim 33
Dependent Claim
22 words
The method according to claim 29, including the step of periodically interrupting the connection of an electrode and one of said ends.
Claim 34
Dependent Claim
14 words
The method according to claim 29, including the step of periodically interconnecting the electrodes.
Claim 35
Dependent Claim
20 words
The method according to claim 29, including the step of periodically reversing the connections of the electrodes to said ends.
Claim 36
Dependent Claim
34 words
The method according to claim 1, in which said electric current is generated and said value is recorded at each of a plurality of positions spaced along a descending path in said ocean current.
Claim 37
Dependent Claim
36 words
The method according to claim 1, in which the detector is moved along a descending path in said ocean current and said value is recorded at each of a plurality of positions spaced along said path.
Claim 38
Dependent Claim
22 words
The method according to claim 34, in which the detector rotates about a substantially vertical axis as it descends along said path.
Claim 39
Dependent Claim
16 words
The method according to claim 1, in which the horizontal velocity of said detector is zero.
Claim 40
Dependent Claim
37 words
The method according to claim 1, in which the horizontal velocity of said detector substantially equals and has the same direction as the horizontal velocity of the ocean current at the depth at which it is located.
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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |