Split beam sonar

• US 4,982,384 A
• Filed: 09/27/1971
• Issued: 01/01/1991
• Est. Priority Date: 09/27/1971
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Pipkin, Edward L., Salsman, Garrett G.
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Pihulic, Daniel T.
• Application Number:
  US05/184,237
• Time in Patent Office: 7,036 Days
• Field of Search: 340/3 R, 340/3 E, 343/7.3, 343/7.5, 343/7.4, 367/87, 367/113, 367/95, 367/97, 367/99
• US Class Current: 367/95
• CPC Class Codes: G01S 15/003 Bistatic sonar systems; Multistatic sonar systems
• CPC Class Codes: G01S 15/18 wherein range gates are used
• CPC Class Codes: G01S 15/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S15/46
• CPC Class Codes: G01S 7/6272 producing cursor lines and indicia by electronic means

Abstract

A sonar system is disclosed that includes contiguously angularly disposed d oppositely rotated transmitting and receiving transducers for broadcasting an acoustic signal and for receiving target echoes thereof, respectively, at different angles from within overlapping zones thereof within an aqueous medium. A gated transmitter is employed to timely energize said transmitting transducer, and a gated target seeking receiver is employed to process the output signal of said receiving transducer. A cathode ray tube readout displays target signals from said receiver. A light sensitive probe produces an electrical output signal in response to a target signal displayed on said cathode ray tube which is used for gating the aforesaid transmitter and receiver in such manner as to accentuate the displayed target signal being probed at any given instant.

Claims

1. An echo-search system, comprising in combination:

means for broadcasting a predetermined energy signal at a first predetermined angle with respect to a reference datum within a predetermined environmental medium;

means for receiving a reflected target echo of the aforesaid broadcast predetermined energy signal at a second angle that is substantially equal to the aforesaid first predetermined angle but opposite thereof with respect to said reference datum within said predetermined environmental medium;

means connected to the output of said receiving means for reading out the reflected target echo received thereby in terms of a visual radiant energy signal on a display screen; and

means connected to the aforesaid broadcasting and receiving means for the timely actuation of said broadcasting and receiving means in response to receiving the aforesaid visual radiant energy signal from said display screen.

2. The device of claim 1, wherein said echo-search system comprises a sonar system, and said predetermined energy broadcast signal and the aforesaid received reflected target echo thereof each comprises acoustical energy signals.

3. The device of claim 1, wherein said means connected to the output of said receiving means for reading out the reflected target echo received thereby in terms of a visual radiant energy signal on a display screen is an oscilloscope incorporating a cathode ray tube.

4. The device of claim 1, wherein said means effectively connected to the aforesaid broadcasting and receiving means for timely actuation of said broadcasting and receiving means in response to receiving the aforesaid visual radiant energy signal from said display screen comprises:

a probe, having a radiant energy sensitive input and an output, for producing an electrical output signal in response to and proportional to the intensity of the aforesaid visual radiant energy signal whenever it is placed for the reception thereof;

a variable delay connected to the output of said probe; and

a clock pulse generator connected between the output of said delay and an actuation input of said broadcasting means.

5. The device of claim 1, wherein said means for broadcasting a predetermined energy signal at a first predetermined angle with respect to a reference datum within a predetermined environmental medium comprises:

a transmitter; and

a transmitting transducer, adapted for being rotated about a predetermined axis, connected to the output of said transmitter.

6. The device of claim 5, wherein said transmitter comprises:

an oscillator for producing a predetermined frequency signal;

a gate having a data signal input, a gating control input, and an output, with the data signal input connected to the output of said oscillator; and

a power amplifier connected to the output of said gate.

7. The device of claim 5, wherein said transmitting transducer comprises an electroacoustical transducer for broadcasting acoustical energy with a predetermined radiation pattern in response to an electrical signal supplied thereto by said transmitter.

8. The device of claim 1, wherein said means for receiving a reflected target echo of the aforesaid predetermined energy signal at a second angle that is substantially equal to the aforesaid first predetermined angle but opposite thereof with respect to said reference datum within said predetermined environmental medium comprises:

a receiver; and

a receiving transducer, adapted for being rotated about a predetermined axis, connected to the input of said receiver.

9. The device of claim 8, wherein said receiver comprises:

a trio of amplifiers;

a trio of filters, each of which has an input and an output, with the inputs thereof respectively connected to the outputs of said trio of amplifiers and with the output of one thereof connected to the input of the aforesaid readout means;

a pair of gates, each of which has a data signal input, a gating control input, and an output, with the inputs thereof respectively connected to the outputs of the remaining pair of the aforesaid trio of filters;

a pair of integrators respectively connected to the outputs of said pair of gates;

a subtract circuit connected to the outputs of said integrators for producing an error output signal whose amplitude and polarity are proportional to the algebraic difference between the signals supplied thereto by said integrators;

a servo motor connected to the output of said subtract circuit adapted for having an output shaft rotation that is proportional in amount and direction to the amplitude and polarity of the aforesaid error output signal, respectively; and

a transducer angle drive connected to the shaft output of said servo motor for the driving of said transmitting and receiving transducers at equal and opposite angles from said reference datum in an angular amount that is proportional to the aforesaid error output signal.

10. The device of claim 8, wherein said receiving transducer comprises:

a first energy converter for producing a first electrical output signal that is proportional to a predetermined energy signal received from within a first predetermined lobular response pattern;

a second energy converter, contiguously disposed with said first energy converter, for producing a second electrical output signal that is proportional to that portion of said predetermined energy signal received from within a second predetermined lobular response pattern that partially overlaps the aforesaid first predetermined lobular response pattern; and

a third energy converter, contiguously disposed with said second energy converter, for producing a third electrical output signal that is proportional to that portion of said predetermined energy signal received from within a third predetermined lobular response pattern that partially overlaps the aforesaid second predetermined lobular response pattern.

11. A split beam sonar system, comprising in combination:

an adjustable frequency oscillator;

a first control gate having a data signal input, a gating control input, and an output, with the data signal input thereof connected to the output of said adjustable frequency oscillator;

a power amplifier connected to the output of said first control gate;

a rotatable transmitting electroacoustical transducer connected to the output of said power amplifier for broadcasting acoustical energy within a predetermined radiation pattern directed at a predetermined angle with respect to a given reference;

a rotatable receiving electroacoustical transducer having a first energy converter for producing a first electrical output signal that is proportional to a predetermined acoustical energy signal received from within a first predetermined lobular response pattern, a second energy converter contiguously disposed with said first energy converter for producing a second electrical output signal that is proportional to that portion of said predetermined acoustical energy signal received from within a second predetermined lobular response pattern that partially overlaps the aforesaid first predetermined lobular response pattern, and a third energy converter contiguously disposed with said second energy converter for producing a third electrical output signal that is proportional to that portion of said predetermined acoustical energy signal received from within a third predetermined lobular response pattern that partially overlaps the aforesaid second predetermined lobular response pattern;

a trio of amplifiers respectively connected to the outputs of the first, second, and third energy converters of the aforesaid rotatable receiving electroacoustical transducer;

a trio of filters, each of which has an input and an output, with the inputs thereof respectively connected to the outputs of the aforesaid trio of amplifiers;

a readout, having a cathode ray tube display means incorporated therein or displaying acquired targets as light pulses on the screen thereof, connected to the output of the one filter of the aforesaid trio of filters that is effectively connected to the second energy converter of said rotatable receiving electroacoustical transducer;

a pair of control gates, each of which has a data signal input, a gating control input, and an output, with the data signal inputs thereof respectively connected to the outputs of the remaining pair of the aforesaid trio of filters;

a pair of integrators respectively connected to the outputs of said pair of control gates;

a subtract circuit having a pair of inputs and an output, with the inputs thereof respectively connected to the outputs of said integrators, for producing an error signal that is proportional to the amplitude and polarity difference between the outputs of said pair of integrators;

a reversible servo motor connected to the output of said subtract circuit for providing an output shaft rotation that is proportional to said error signal;

a transducer angle drive means connected between the output shaft of said reversible servo motor and the aforesaid transmitting and receiving transducers for effecting the respective rotation thereof at equal and opposite angles with respect to the aforesaid given reference in response to the shaft output of the aforesaid reversible servo motor;

a portable manually operable light responsive probe, having a light sensitive input and an output, for generating an electrical signal at the output thereof in response to a lighted target displayed on the screen of the cathode ray tube of the aforesaid readout, with the output thereof connected to the gating control inputs of the aforesaid pair of control gates;

an adjustable delay line connected to the output of said probe; and

an adjustable frequency clock pulse generator connected between the output of said adjustable delay line and the gating control input of said first control gate.

12. The invention of claim 11, further characterized by:

a variable threshold detector connected to the output of said subtract circuit;

an acquisition detector connected to the output of said threshold detector; and

a manual over-ride connected to the aforesaid servo motor for manually effecting the rotation thereof in such manner as to provide expeditious environmental medium scanning by the aforesaid rotatable transmitting and receiving transducers.