Patent US3757286A successfully refreshed from Google Patents.
US3757286A
Expired / Lapsed
US
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Apparatus for detecting aquatic animals
Assignee: Individual
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Filing: 1970-08-07
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Granted: 1973-09-04
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Expires: 1990-08-07
Abstract
Abstract A method for detecting shrimp and certain other aquatic animals having specific motional responses when subjected to a pulsed electric field. An instrumented housing, suitable for towing along the sea bottom behind a powered vessel, includes an electrical pulse generator, a suitably spaced electrode array, and an ultrasonic Doppler detection system. Repetitive electrical pulses are discharged between the spaced electrodes as the vehicle is towed along the bottom. As shrimp and other susceptive aquatic animals on or near the sea bottom attempt to escape the influence of the pulsed electric field, their movements are detected by the ultrasonic Doppler system. Shrimp respond by a jumping movement during which relatively high velocities are achieved for brief periods of time. Fishes respond by swimming at moderate velocities. Doppler signals indicative of shrimp and fish are received in the towing vessel. The relatively high pitched Doppler signals caused by jumping shrimp are discriminated from the relatively lower pitched signals caused by fishes. The continuous indication of shrimp or other specific marine animals passing in close proximity to the towed vehicle provides a quantitative basis for evaluating their concentrations and probable catch rates.
Inventors
- 👤 J Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:48
CPC Classifications
A; A01; A01K; A01K79/00; A01K79/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
140 words
Apparatus for detecting and discriminating aquatic animals on the basic of their characTeristic locomotory responses to an electrical stimulus comprising: an instrumented vehicle suitable for towing through an aquatic environment; spaced electrodes at least one of which is appended from the said vehicle for electrifying an adjacent volume of water; means for intermittently passing electrical current between the said spaced electrodes; means for transmitting ultrasonic energy into the water in a wide angle between pattern adjacent the said vehicle; means for receiving ultrasonic energy reflected from objects in the water adjacent the said vehicle; means for deriving an output signal dependent on the frequency difference between said transmitted and received ultrasonic energy, whereby said output may be characterized to permit the detection and discrimination of various aquatic animals; and means for indicating successive output events of the said output signal.
Claim 2
Dependent Claim
140 words
Apparatus for detecting and discriminating aquatic animals on the basic of their characTeristic locomotory responses to an electrical stimulus comprising: an instrumented vehicle suitable for towing through an aquatic environment; spaced electrodes at least one of which is appended from the said vehicle for electrifying an adjacent volume of water; means for intermittently passing electrical current between the said spaced electrodes; means for transmitting ultrasonic energy into the water in a wide angle between pattern adjacent the said vehicle; means for receiving ultrasonic energy reflected from objects in the water adjacent the said vehicle; means for deriving an output signal dependent on the frequency difference between said transmitted and received ultrasonic energy, whereby said output may be characterized to permit the detection and discrimination of various aquatic animals; and means for indicating successive output events of the said output signal.
Claim 3
Dependent Claim
31 words
Apparatus for detecting aquatic animals as described in claim 1 wherein the said instrumented vehicle includes runners appended therefrom to provide a sled-like configuration suitable for towing on the sea bottom.
Claim 4
Dependent Claim
32 words
Apparatus as described in claim 1 wherein the said indicating means is located aboard a powered vessel; and an electrically conductive cable connects the said instrumented vehicle with the said indicating means.
Claim 5
Dependent Claim
23 words
Apparatus as described in claim 1 wherein the said indicating means is an amplified difference frequency signal made audible by an electroacoustic transducer.
Claim 6
Dependent Claim
44 words
Apparatus as described in claim 1 including a discriminator circuit for selectively passing only difference frequency signals exceeding a predetermined threshold frequency so that movements of objects in the water adjacent the said vehicle are indicated only when a corresponding threshold velocity is exceeded.
Claim 7
Dependent Claim
22 words
Apparatus as described in claim 1 including: means for graphically recording the said electrical output signal as a function of elapsed time.
Claim 8
Dependent Claim
198 words
Apparatus for detecting and discriminating aquatic animals comprising: an instrumented vehicle suitable for towing through the water behind a powered vessel; runners appended from the said vehicle to facilitate towing along the sea bottom; an electrically conductive cable connecting the said vehicle with the aforementioned powered vessel; spaced electrodes appended from the said instrumented vehicle for electrifying an adjacent volume of water; means for intermittently passing electrical current through the water between the said electrodes; an oscillator for generating electrical signals of an ultrasonic frequency; a first transducer for transmitting ultrasonic energy in a wide angle beam pattern into the water adjacent the said vehicle; a second transducer having an electrical output in response to received ultrasonic energy reflected from objects in the water adjacent the said vehicle; means for amplifying electrical signals from the said second transducer; a mixer circuit for combining signals from the said oscillator with the output signal from the said amplifying means to obtain difference frequency signals; and means aboard the aforementioned powered vessel for graphically recording successive occurrences of the aforementioned difference frequency signals to indicate the relative concentrations of aquatic animals passing within the influence field of the said spaced electrodes.
Claim 9
Dependent Claim
198 words
Apparatus for detecting and discriminating aquatic animals comprising: an instrumented vehicle suitable for towing through the water behind a powered vessel; runners appended from the said vehicle to facilitate towing along the sea bottom; an electrically conductive cable connecting the said vehicle with the aforementioned powered vessel; spaced electrodes appended from the said instrumented vehicle for electrifying an adjacent volume of water; means for intermittently passing electrical current through the water between the said electrodes; an oscillator for generating electrical signals of an ultrasonic frequency; a first transducer for transmitting ultrasonic energy in a wide angle beam pattern into the water adjacent the said vehicle; a second transducer having an electrical output in response to received ultrasonic energy reflected from objects in the water adjacent the said vehicle; means for amplifying electrical signals from the said second transducer; a mixer circuit for combining signals from the said oscillator with the output signal from the said amplifying means to obtain difference frequency signals; and means aboard the aforementioned powered vessel for graphically recording successive occurrences of the aforementioned difference frequency signals to indicate the relative concentrations of aquatic animals passing within the influence field of the said spaced electrodes.
Claim 10
Independent Claim
118 words
The method of detecting and discriminating aquatic animals comprising: towing an instrumented vehicle through a body of water inhabited by aquatic animals having a locomotory response to an electrical stimulus; periodically discharging electrical current through a volume of water adjacent the said vehicle; transmitting ultrasonic energy into the water in a wide angle beam pattern adjacent the said vehicle; receiving ultrasonic energy reflected by aquatic animals passing adjacent the said vehicle; deriving an electrical output signal dependent on the frequency difFerence between the said transmitted and received ultrasonic energy; whereby the presence of susceptive aquatic animals passing within the influence of the said electrical current discharges is indicated by the amplitude and frequency characteristics of the output signal.
Claim 11
Independent Claim
118 words
The method of detecting and discriminating aquatic animals comprising: towing an instrumented vehicle through a body of water inhabited by aquatic animals having a locomotory response to an electrical stimulus; periodically discharging electrical current through a volume of water adjacent the said vehicle; transmitting ultrasonic energy into the water in a wide angle beam pattern adjacent the said vehicle; receiving ultrasonic energy reflected by aquatic animals passing adjacent the said vehicle; deriving an electrical output signal dependent on the frequency difFerence between the said transmitted and received ultrasonic energy; whereby the presence of susceptive aquatic animals passing within the influence of the said electrical current discharges is indicated by the amplitude and frequency characteristics of the output signal.
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) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |