US3618007A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertical obstacle profiling sonar
Assignee: United States Department of the Navy
•
Filing: 1969-11-18
•
Granted: 1971-11-02
•
Expires: 1989-11-18
Abstract
Abstract The sonar functions in a pulsed active-mode utilizing a projector to insonify a fan-shaped region of an ocean floor area in front of the submersible. Backscattered signal returns are received by two hydrophones having acoustic centers located in close proximity (about 0.35 inch) one to the other. Range is determined by elapsed time between transmission and reception. Direction in a vertical plane relative to the axis of the submersible is determined by the relative phase between the signal outputs of the vertically spaced hydrophones. The outputs are coupled to a signal processor employing a time-varying gain to compensate for beam-spreading losses and then to separate clipper amplifiers. The positive transition of one clipper output is used to reset a sawtoothed generator and the negative transition of the other clipper triggers a pulse generator. Combining the outputs of the sawtooth and pulse generators provides phase information proportional to the arrival angle of the return signal. When combined with range, the results can be displayed to provide a vertical and horizontal coordinate display for navigation purposes. An envelope detector is connected to one of the signal processor channels to intensity modulate the display for highlighting stronger returns.
Inventors
- 👤 Victor C Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:05
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/02; G01S15/06; G01S15/42; G01S7/00; G01S7/02; G01S7/04; G01S7/06; G01S7/10; G01S7/52; G01S7/523; G01S7/526; G01S7/529; G01S7/56; G01S7/62; G01S7/6218; Y; Y10; Y10S; Y10S367/00; Y10S367/90
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
200 words
Pulsed active-mode apparatus for discriminatively detecting ocean bottom irregularities comprising: a transducer assembly including: an acoustic signal beam projector, pulse gating means for driving said projector, and a pair of signal receivers having acoustic centers spaced vertically one from the other for producing a phase difference phi in their signal outputs equal to kd sin Beta wherein k is the wave number of the signal, d is the center spacing and Beta is the vertical arrival angle of the received signal, said spacing d being sufficiently small to permit phi to remain within a single cycle (2 pi ) range for all values of Beta , signal processing means or measuring the phase difference of said receiver outputs, said means formed of a pair of signal processing channels each having an input coupled to a separate receiver output, means responsively coupled to said processing means for displaying said phase difference measurements, and a signal-discriminating circuit means coupling one of said channels to said display, said circuit means including means for intensity modulating the display in accordance with the strength of the signal in said channel whereby relatively strong signal returns produced by relatively pronounced bottom irregularities can be discriminatively displayed.
Claim 2
Dependent Claim
200 words
Pulsed active-mode apparatus for discriminatively detecting ocean bottom irregularities comprising: a transducer assembly including: an acoustic signal beam projector, pulse gating means for driving said projector, and a pair of signal receivers having acoustic centers spaced vertically one from the other for producing a phase difference phi in their signal outputs equal to kd sin Beta wherein k is the wave number of the signal, d is the center spacing and Beta is the vertical arrival angle of the received signal, said spacing d being sufficiently small to permit phi to remain within a single cycle (2 pi ) range for all values of Beta , signal processing means or measuring the phase difference of said receiver outputs, said means formed of a pair of signal processing channels each having an input coupled to a separate receiver output, means responsively coupled to said processing means for displaying said phase difference measurements, and a signal-discriminating circuit means coupling one of said channels to said display, said circuit means including means for intensity modulating the display in accordance with the strength of the signal in said channel whereby relatively strong signal returns produced by relatively pronounced bottom irregularities can be discriminatively displayed.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1 wherein said signal receivers have essentially the same beam patterns and orientations as the projector.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 wherein said signal processing means includes circuit elements permitting measurement of the axis-crossing phase difference between the signal outputs of the receivers.
Claim 5
Dependent Claim
39 words
The apparatus of claim 3 wherein said display means is an oscilloscope, the apparatus further including circuit means coupling said projector pulse gating means with said oscilloscope for triggering a horizontal sweep providing a time axis for said display.
Claim 6
Dependent Claim
84 words
The apparatus of claim 4 wherein one of said signal processing channels includes a phase-responsive sawtooth generator having an output coupled to said oscilloscope for driving its vertical input, the other of said channels including a phase-responsive pulse generator and means for gating the generated pulse into said oscilloscope, said gated pulse being applied to said sawtooth vertical input for intensifying its sawtooth pattern at a particular location, said location thus being representative of the phase difference between said sawtooth generator and pulse generator.
Claim 7
Dependent Claim
22 words
The apparatus of claim 5 wherein said intensity controlling discrimination means is coupled to said oscilloscope through said generated pulse gating means.
Claim 8
Dependent Claim
55 words
The apparatus of claim 1 further including an analogue coordinate transformation computer coupled between the output of the said signal processing means and the display for connecting phase difference measurements into horizontal and vertical range coordinates, said computer having an input coupled to said pulsed projector driving means for supplying range data to the computer.
Claim 9
Dependent Claim
103 words
The apparatus of claim 7 wherein one of said signal processing channels includes a phase-responsive sawtooth generator and the other channel includes a phase-responsive pulse generator, said signal processing means further including means for gating said channel generated pulse to said sawtooth generator output for holding the voltage of said sawtooth at constant level pending generation of a succeeding pulse, the voltage increMents on the sawtooth produced by succeeding pulses being a measure of the phase differences and said increments providing inputs for said computer representative of said arrival angle Beta , said computer connecting said angle and range inputs into said coordinates.
Claim 10
Dependent Claim
12 words
The apparatus of claim 1 wherein said pair of receivers are interleaved.
Claim 11
Dependent Claim
28 words
The apparatus of claim 1 wherein said signal processing means includes a time-varying gain circuit adapted to compensate for spreading losses in said projected and returned beam signals.
References Cited (Backward Citations)
US3381264A
Cited
US3469230A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |