Sonar system using frequency bursts

• US 9,354,312 B2
• Filed: 01/30/2013
• Issued: 05/31/2016
• Est. Priority Date: 07/06/2012
• Status: Active Grant

• Current Assignee: Navico Incorporated (Brunswick Corporation)
• Original Assignee: Navico Holding A.S. (Brunswick Corporation)
• Inventors: Proctor, Alan
• Primary Examiner(s): Lobo, Ian J
• Application Number:
  US13/754,519
• Publication Number:
  US 20140010048A1
• Time in Patent Office: 1,217 Days
• Field of Search: 367/88, 367/101
• US Class Current: 1/1
• CPC Class Codes: G01S 15/102 using transmission of pulses having some particular characteristics
• CPC Class Codes: G01S 15/89 for mapping or imaging
• CPC Class Codes: G01S 15/8902 Side-looking sonar

Abstract

A sonar system using frequency bursts. A sonar system for use with a vessel may include a sonar module having a transmitting element configured to generate a transmit signal, where the transmit signal comprises one or more bursts, and where at least one burst comprises a first portion having a first frequency and a second portion having a second frequency different than the first frequency. The sonar system may also include a transducer array in communication with the sonar module, where the transducer array is configured to (i) receive the transmit signal from the transmitting element, (ii) produce one or more sonar beams based on the first frequency and the second frequency, and (iii) receive one or more sonar return signals from an underwater environment.

Claims

1. A sonar system for imaging an underwater environment underneath a vessel configured to travel along a surface of a body of water, wherein the vessel defines a port side and a star board side, the sonar system comprising:

a housing mountable to the vessel;

a linear downscan transducer element having a substantially rectangular shape, positioned within the housing, and configured to produce a fan-shaped sonar beam directly beneath the vessel, wherein the fan-shaped sonar beam has a narrow beamwidth in a direction parallel to a fore-to-aft direction of the vessel and a wide beamwidth in a direction perpendicular to the fore-to-aft direction of the vessel;

a first linear sidescan transducer element have a substantially rectangular shape, wherein the first linear sidescan transducer element is positioned within the housing and aimed to the port side of the vessel;

a second linear sidescan transducer element have a substantially rectangular shape, wherein the second linear sidescan transducer element is positioned within the housing and aimed to the starboard side of the vessel; and

a sonar module electrically connected to at least the linear downscan transducer element and configured to transmit one or more transmit signals to at least the linear downscan transducer element, wherein the sonar module is configured to transmit at at least a first frequency and a second frequency, wherein the second frequency is different than the first frequency;

wherein the linear downscan transducer element is configured to produce a first fan-shaped sonar beam at the first frequency into the underwater environment;

wherein the linear downscan transducer element is configured to produce a second fan-shaped sonar beam at the second frequency into the underwater environment;

wherein the linear downscan transducer element is configured to receive first sonar returns from the underwater environment and convert the first sonar returns to first sonar return data;

wherein the first linear sidescan transducer element is configured to receive second sonar returns from the underwater environment and convert the second sonar returns to second sonar return data;

wherein the second linear sidescan transducer element is configured to receive third sonar returns from the underwater environment and convert the third sonar returns to third sonar return data;

wherein the sonar module is configured to receive the first sonar return data from the linear downscan transducer element and filter the first sonar return data based on the first frequency, wherein the sonar module is configured to receive the second sonar return data from the first linear sidescan transducer element and filter the second sonar return data based on the second frequency, and wherein the sonar module is configured to receive the third sonar return data from the second linear sidescan transducer element and filter the third sonar return data based on the second frequency.

2. The sonar system of claim 1, wherein the linear downscan transducer element is configured to produce each of the first fan-shaped sonar beam and the second fan-shaped sonar beam from a down face, a left face, and a right face of the linear downscan transducer element.

3. The sonar system of claim 2, wherein each of the first fan-shaped sonar beam and the second fan-shaped sonar beam produced by the linear downscan transducer element provides substantially continuous sonar coverage from the port side of the vessel to the starboard side of the vessel.

4. The sonar system of claim 2, wherein the first linear sidescan transducer element and the second linear sidescan transducer element are each configured as receive-only transducer elements.

5. The sonar system of claim 1, wherein the sonar module comprises a sonar signal processor configured to process the filtered first sonar data, the filtered second sonar data, and the filtered third sonar data.

6. The sonar system of claim 1, wherein the sonar module is configured to generate a first transmit signal at the first frequency for a first duration of time, wherein the sonar module is configured to generate a second transmit signal at the second frequency for a second duration of time, wherein the first duration of time is shorter than the second duration of time.

7. The sonar system of claim 1, wherein the first frequency is selected to be about 790 kilohertz (kHz) and the second frequency is selected to be about 820 kHz.

8. The sonar system of claim 1, wherein the first frequency is selected to be about 430 kilohertz (kHz) and the second frequency is selected to be 480.

9. The sonar system of claim 1, wherein the sonar module is configured to generate the transmit signal as a pulse having at least a first portion at the first frequency and at least a second portion at the second frequency.

10. The sonar system of claim 9, wherein the sonar module is configured to generate the transmit signal such that the first portion defines a first duration of time and the second portion defines a second duration of time, wherein the first duration of time is shorter than the second duration of time.

11. The sonar system of claim 1, wherein the sonar module is electrically connected to the first linear sidescan transducer element and the second linear sidescan transducer element and configured to transmit the one or more transmit signals to the first linear sidescan transducer element and the second linear sidescan transducer element, wherein the first linear sidescan transducer element is configured to produce a fan-shaped sonar beam at the second frequency into the underwater environment, and wherein the second linear sidescan transducer element is configured to produce a fan-shaped sonar beam at the second frequency into the underwater environment.

12. The sonar system of claim 1 further comprising a display element configured to display at least one image of the underwater environment based on at least one of the first sonar return data, the second return data, and the third sonar return data.

13. A method for imaging an underwater environment underneath a vessel configured to travel along a surface of a body of water, the method comprising:

transmitting, via a sonar module, one or more transmit signals to a linear downscan transducer element, wherein the sonar module is electrically connected to the linear downscan transducer element, wherein the sonar module is configured to transmit at at least a first frequency and a second frequency, wherein the second frequency is different than the first frequency;

producing, at the first frequency, a first fan-shaped sonar beam into the underwater environment from the linear downscan transducer element, wherein the linear downscan transducer element has a substantially rectangular shape and is positioned within the housing and configured to produce a fan-shaped sonar beam directly beneath the vessel, wherein the fan-shaped sonar beam has a narrow beamwidth in a direction parallel to a fore-to-aft direction of the vessel and a wide beamwidth in a direction perpendicular to the fore-to-aft direction of the vessel;

producing, at the second frequency, a second fan-shaped sonar beam into the underwater environment;

receiving, via the linear downscan transducer element, first sonar returns from the underwater environment and converting the first sonar returns into first sonar return data;

receiving, via the first linear sidescan transducer element, second sonar returns from the underwater environment and converting the second sonar returns into second sonar return data;

receiving, via the second linear sidescan transducer element, third sonar returns from the underwater environment and converting the third sonar returns into third sonar return data;

receiving, via the sonar module, the first sonar return data from the linear downscan transducer element and filtering the first sonar return data based on the first frequency;

receiving, via the sonar module, the second sonar return data from the first linear sidescan transducer element and filtering the second sonar return data based on the second frequency; and

receiving, via the sonar module, the third sonar return data from the second linear sidescan transducer element and filtering the third sonar return data based on the second frequency.

14. The method of claim 13, wherein the linear downscan transducer element is configured to produce each of the first fan-shaped sonar beam and the second fan-shaped sonar beam from a down face, a left face, and a right face of the linear downscan transducer element.

15. The method of claim 14, wherein each of the first fan-shaped sonar beam and the second fan-shaped sonar beam produced by the linear downscan transducer element provides substantially continuous sonar coverage from the port side of the vessel to the starboard side of the vessel.

16. The method of claim 14, wherein the first linear sidescan transducer element and the second linear sidescan transducer element are each configured as receive-only transducer elements.

17. The method of claim 13, wherein the sonar module is configured to generate a first transmit signal at the first frequency for a first duration of time, wherein the sonar module is configured to generate a second transmit signal at the second frequency for a second duration of time, wherein the first duration of time is shorter than the second duration of time.

18. The method of claim 13, wherein the sonar module is configured to generate the transmit signal as a pulse having at least a first portion at the first frequency and at least a second portion at the second frequency.

19. The method of claim 18, wherein the sonar module is configured to generate the transmit signal such that the first portion defines a first duration of time and the second portion defines a second duration of time, wherein the first duration of time is shorter than the second duration of time.

20. The method of claim 13 further comprising:

transmitting, via the sonar module, the one or more transmit signals to the first linear sidescan transducer element and the second linear sidescan transducer element;

producing, via the first linear sidescan transducer element, a fan-shaped sonar beam at the second frequency into the underwater environment; and

producing, via the second linear sidescan transducer element, a fan-shaped sonar beam at the second frequency into the underwater environment.

21. The method of claim 13 further comprising displaying, via a display element, at least one image of the underwater environment based on at least one of the first sonar return data, the second return data, and the third sonar return data.