US3842398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for deployment of expendable velocimeter to eliminate doppler shift error in the measurements
Assignee: MASSA DONALD P COHASSET
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Filing: 1972-05-08
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Granted: 1974-10-15
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Expires: 1992-05-08
Abstract
Abstract A correction is applied to a sound velocity vs. depth profile in order to eliminate a Doppler shift caused by the relative speed between a transmitter on a velocimeter dropping through the ocean and a receiver on a hydrophone moving parallel to the surface of the ocean. The Doppler shift error is controlled by a selection of the meter launch conditions so that the correction factor is predictable. Preferably, the hydrophone carries the velocimeter until the instant of launch so that the meter falls straight down from the hydrophone. Similar techniques may be used to correct the Doppler shift errors when the velocimeter is dropped from an aircraft and the hydrophone pickup is stationary on the surface of the ocean.
Inventors
- 👤 D Massa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:05
CPC Classifications
G; G01; G01H; G01H5/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
122 words
In a system for directly measuring the sound velocity vs. depth profile along a vertical axis in a body of water, velocimeter means responsive to the velocity of sound in the immediate vicinity of said velocimeter for generating an acoustic signal in said water, said signal having a frequency which is proportional to said velocity of sound, signal pickup means including a length of electrical cable towing a hydrophone for converting said acoustic signal into an electrical signal, means for releasably securing said velocimeter in close proximity to said hydrophone during said tow, and means responsive to a command signal for releasing said securing means to drop said velocimeter from the point where said hydrophone is located at the instant of drop.
Claim 2
Dependent Claim
122 words
In a system for directly measuring the sound velocity vs. depth profile along a vertical axis in a body of water, velocimeter means responsive to the velocity of sound in the immediate vicinity of said velocimeter for generating an acoustic signal in said water, said signal having a frequency which is proportional to said velocity of sound, signal pickup means including a length of electrical cable towing a hydrophone for converting said acoustic signal into an electrical signal, means for releasably securing said velocimeter in close proximity to said hydrophone during said tow, and means responsive to a command signal for releasing said securing means to drop said velocimeter from the point where said hydrophone is located at the instant of drop.
Claim 3
Dependent Claim
91 words
The invention in claim 1 and an amplIfier, strip chart recorder means connected to the output of said amplifier for recording the magnitudes of said electrical signal along one coordinate axis on a chart, transport means for moving said chart with constant linear speed perpendicular to said coordinate axis, means for connecting said hydrophone signal to feed said signals to the input of said amplifier, means associated with said amplifier for converting the electrical signal received from said hydrophone into an electrical signal of varying magnitude for driving said recorder means.
Claim 4
Dependent Claim
83 words
The invention in claim 1 wherein said means for releasably securing said velocimeter to said hydrophone includes electromagnetic means associated with said hydrophone and a magnetic conducting means associated with said velocimeter whereby said velocimeter is held securely attached to said hydrophone when said magnetic conducting means is in contact with said electromagnet and when said electromagnet is energized, electrical power source means for energizing said electromagnet, and switching means for controlling the connection of said source of electrical power to said electromagnet.
Claim 5
Dependent Claim
31 words
The invention in claim 3 and strip chart recorder means actuated simultaneously with said switching means for starting said recorder when said source of electromagnet power is disconnected from said electromagnet.
Claim 6
Independent Claim
144 words
A system for directly measuring the sound velocity vs. depth profile along an axis in a body of water comprising velocimeter means for generating a signal having a frequency which varies as a function of the velocity of sound in the water in the immediate vicinity of the velocimeter, a hydrophone for picking up said signal, an electrical cable connected to said hydrophone, electromagnetic means for attaching said velocimeter to said hydrophone responsive to an energizing of said electromagnet, means for supplying energizing power to said electromagnet responsive to an operation of a switching means, recorder means for making a continuously variable recording of the generated signals as received by the hydrophone, and means for starting said recorder synchronized with operation of said switching means to deenergize said electromagnet means whereby said recorder is started when the energizing power is removed from said electromagnet.
Claim 7
Independent Claim
144 words
A system for directly measuring the sound velocity vs. depth profile along an axis in a body of water comprising velocimeter means for generating a signal having a frequency which varies as a function of the velocity of sound in the water in the immediate vicinity of the velocimeter, a hydrophone for picking up said signal, an electrical cable connected to said hydrophone, electromagnetic means for attaching said velocimeter to said hydrophone responsive to an energizing of said electromagnet, means for supplying energizing power to said electromagnet responsive to an operation of a switching means, recorder means for making a continuously variable recording of the generated signals as received by the hydrophone, and means for starting said recorder synchronized with operation of said switching means to deenergize said electromagnet means whereby said recorder is started when the energizing power is removed from said electromagnet.
Claim 8
Dependent Claim
52 words
The invention in claim 5 wherein said electrical cable comprises common cable conductor means for connecting to said power supply means and for connecting the hydrophone to said recorder means, and common selective switching means for alternately connecting said common cable conductor to either said electromagnet power supply means or said recorder.
Claim 9
Independent Claim
113 words
A system for aerial survey of the sound velocity vs. depth profiles of a body of water comprising an expendable velocimeter means launched from said aircraft, said velocimeter being streamlined for an efficient free fall through the water and having means for generating an acoustic signal having a frequency which varies in accordance with the variation of the velocity of sound in the immediate vicinity of the velocimeter during its fall, hydrophone means suspended in said body of water for receiving said acoustic signals and for transmitting a corresponding signal to said aircraft, the distance between the hydrophone position and the launching point of said expendable velocimeter being greater than approximately one mile.
Claim 10
Independent Claim
113 words
A system for aerial survey of the sound velocity vs. depth profiles of a body of water comprising an expendable velocimeter means launched from said aircraft, said velocimeter being streamlined for an efficient free fall through the water and having means for generating an acoustic signal having a frequency which varies in accordance with the variation of the velocity of sound in the immediate vicinity of the velocimeter during its fall, hydrophone means suspended in said body of water for receiving said acoustic signals and for transmitting a corresponding signal to said aircraft, the distance between the hydrophone position and the launching point of said expendable velocimeter being greater than approximately one mile.
Claim 11
Dependent Claim
25 words
The invention in claim 7 and recorder means in an aircraft making the launch for recording the received hydrophone signals as a function of time.
References Cited (Backward Citations)
US3341808A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |