Sonar imaging techniques for objects in an underwater environment

1. A method for imaging an underwater environment, the method comprising:

receiving first sonar data based on first sonar returns from one or more first sonar beams produced by a first transducer element directed toward the underwater environment, wherein the first transducer element defines a first shape and the one or more first sonar beams each define a first beam shape;

receiving second sonar data based on second sonar returns from one or more second sonar beams produced by a second transducer element directed toward the underwater environment, wherein the second transducer element defines a second shape and the one or more second sonar beams each define a second beam shape, wherein the second shape is different than the first shape and the second beam shape is different than the first beam shape;

determining, by a sonar signal processor, an association between at least one of the second sonar returns from the second sonar data and at least one object positioned in the underwater environment;

processing the first sonar data and the second sonar data to form sonar image data, wherein the sonar image data is based on at least one or more of the first sonar returns from the first sonar data and one or more of the second sonar returns associated with the at least one object; and

rendering the sonar image data on a display to form an image of the underwater environment that includes a representation of the at least one object that is formed based on the one or more second sonar returns and a representation of at least a portion of the remainder of the underwater environment that is formed based on the one or more first sonar returns.

2. The method according to claim 1 , further comprising determining an association between at least one of the first sonar returns from the first sonar data and the at least one object positioned in the underwater environment, and wherein processing the first sonar data and the second sonar data to form the sonar image data comprises replacing the at least one of the first sonar returns of the first sonar data associated with the at least one object with the at least one second sonar returns associated with the at least one object.

3. The method according to claim 1 , further comprising determining an association between at least one of the first sonar returns from the first sonar data and the at least one object positioned in the underwater environment, and wherein processing the first sonar data and the second sonar data to form the sonar image data comprises positioning the at least one second sonar returns associated with the at least one object over the at least one of the first sonar returns of the first sonar data associated with the at least one object.

4. The method according to claim 1 , further comprising determining a position of the at least one object within the underwater environment, and wherein processing the first sonar data and the second sonar data to form the sonar image data comprises positioning the at least one second sonar returns associated with the at least one object at a position within the image of the underwater environment corresponding to the position of the at least one object within the underwater environment.

5. The method according to claim 1 , further comprising determining a time associated with capturing the at least one second sonar returns associated with the at least one object within the underwater environment, and wherein processing the first sonar data and the second sonar data to form the sonar image data comprises positioning the at least one second sonar returns associated with the at least one object within the image based on the time associated with capturing the at least one second sonar returns associated with the at least one object.

6. The method according to claim 1 , wherein the first transducer element is directed to produce the first sonar beams in a substantially same direction as the second transducer element is to produce the second sonar beams.

7. The method according to claim 6 , wherein the first transducer element and the second transducer element are each positioned within one or more housings mountable to a watercraft, wherein the watercraft is configured to travel along a surface of a body of water, and wherein the substantially same direction is substantially perpendicular to a plane corresponding to the surface of the body of water.

8. The method according to claim 1 , wherein the first transducer element is a linear transducer element, and wherein the second transducer element is a circular transducer element.

9. The method according to claim 1 , wherein:

the first transducer element comprises a linear downscan transducer element having a substantially rectangular shape, wherein the first sonar beams comprise fan-shaped sonar beams having a relatively narrow beamwidth in a direction parallel to a longitudinal length of the linear downscan transducer element and a relatively wide beamwidth in a direction perpendicular to the longitudinal length of the linear downscan transducer element; and

the second transducer element comprises a circular downscan transducer element, wherein the second sonar beams comprise conical-shaped sonar beams.

10. The method according to claim 9 , wherein the linear downscan transducer element is positioned with the longitudinal length thereof extending in a fore-to-aft direction of a housing mountable to a watercraft, wherein the linear downscan transducer element is positioned within the housing to project the fan-shaped sonar beams in a direction substantially perpendicular to a plane corresponding to a surface of a body of water being traveled by the watercraft, and wherein the circular downscan transducer element is positioned to project the conical-shaped sonar beams in a direction substantially perpendicular to the plane corresponding to the surface of the body of water.

11. The method according to claim 1 , wherein the representation of the at least one object is an image of a fish arch.

12. The method according to claim 1 , wherein the at least one object is a fish.

13. A sonar system for imaging an underwater environment, the sonar system comprising:

a first transducer element directed toward the underwater environment and configured to produce one or more first sonar beams and receive first sonar data based on sonar returns from the one or more first sonar beams, wherein the first transducer element defines a first shape and the one or more first sonar beams each define a first beam shape;

a second transducer element directed toward the underwater environment and configured to produce one or more second sonar beams and receive second sonar data based on sonar returns from the one or more second sonar beams, wherein the second transducer element defines a second shape and the one or more second sonar beams each define a second beam shape, wherein the second shape is different than the first shape and the second beam shape is different than the first beam shape;

a sonar signal processor configured to:

determine an association between at least one of the second sonar returns from the second sonar data and at least one object positioned in the underwater environment;

process the first sonar data and the second sonar data to farm sonar image data, wherein the sonar image data is based on at least one or more of the first sonar returns from the first sonar data and one or more of the second sonar returns associated with the at least one object; and

render the sonar image data on a display to form an image of the underwater environment that includes a representation of the at least one object that is formed based on the one or more second sonar returns and a representation of at least a portion of the remainder of the underwater environment that is formed based on the one or more first sonar returns.

14. The sonar system according to claim 13 , wherein the sonar signal processor is further configured to:

determine an association between at least one of the first sonar returns from the first sonar data and the at least one object positioned in the underwater environment; and

process the first sonar data and the second sonar data to form the sonar image data by replacing the at least one of the first sonar returns of the first sonar data associated with the at least one object with the at least one second sonar returns associated with the at least one object.

15. The sonar system according to claim 13 , wherein the sonar signal processor is further configured to:

determine an association between at least one of the first sonar returns from the first sonar data and the at least one object positioned in the underwater environment; and

process the first sonar data and the second sonar data to form the sonar image data by positioning the at least one second sonar returns associated with the at least one object over the at least one of the first sonar returns of the first sonar data associated with the at least one object.

16. The sonar system according to claim 13 , wherein the sonar signal processor is further configured to:

determine a position of the at least one object within the underwater environment; and

process the first sonar data and the second sonar data to form the sonar image data by positioning the at least one second sonar returns associated with the at least one object at a position within the image of the underwater environment corresponding to the position of the at least one object within the underwater environment.

17. The sonar system according to claim 13 , wherein the first transducer element is directed to produce the first sonar beams in a substantially same direction as the second transducer element is to produce the second sonar beams.

18. The sonar system according to claim 13 , wherein:

the first transducer element comprises a linear downscan transducer element having a substantially rectangular shape, wherein the first sonar beams comprise fan-shaped sonar beams having a relatively narrow beamwidth in a direction parallel to a longitudinal length of the linear downscan transducer element and a relatively wide beamwidth in a direction perpendicular to the longitudinal length of the linear downscan transducer element; and

the second transducer element comprises a circular downscan transducer element, wherein the second sonar beams comprise conical-shaped sonar beams.

19. The sonar system according to claim 13 , wherein the representation of the at least one object is an image of a fish arch.

20. A method for imaging an underwater environment, the method comprising:

receiving first sonar return data from a first transducer element directed toward the underwater environment, wherein the first transducer element defines a first shape;

receiving second sonar return data from a second transducer element directed toward the underwater environment, wherein the second transducer element defines a second shape, wherein the second shape is different than the first shape;

generating sonar image data based on the first sonar return data and the second sonar return data, wherein the sonar image data forms an image representing the underwater environment, wherein the image includes:

a representation of at least one object within the underwater environment that is formed based on the second sonar return data; and

a representation of at least a portion of the remainder of the underwater environment that is fowled based on the first sonar return data; and causing presentation of the sonar image on a display.

21. The method according to claim 20 , wherein generating the sonar image data comprises generating the sonar image data such that the second sonar return data representative of the at least one object replaces the first sonar return data that is representative of the at least one object within the image.

22. The method according to claim 20 , wherein generating the sonar image data comprises generating the sonar image data such that the second sonar return data representative of the at least one object is positioned over the first sonar return data that is representative of the at least one object within the image.

23. The method according to claim 20 , wherein the representation of the at least one object is an image of a fish arch.

24. A sonar system for imaging an underwater environment, the sonar system comprising:

a first transducer element directed toward the underwater environment and configured to receive first sonar return data from the underwater environment, wherein the first transducer element defines a first shape;

a second transducer element directed toward the underwater environment and configured to receive second sonar return data from the underwater environment, wherein the second transducer element defines a second shape, wherein the second shape is different than the first shape;

a processor configured to:

receive the first sonar return data;

receive the second sonar return data; and

generate sonar image data based on the first sonar return data and the second sonar return data, wherein the sonar image data forms an image representing the underwater environment, wherein the image includes:

a representation of at least one object within the underwater environment that is formed based on the second sonar return data; and

a representation of at least a portion of the remainder of the underwater environment that is formed based on the first sonar return data.

25. The sonar system according to claim 24 , further comprising a display configured to present the image.

26. The sonar system according to claim 24 , wherein the processor is configured to generate the sonar image data by generating the sonar image data such that the second sonar return data representative of the at least one object replaces the first sonar return data that is representative of the at least one object within the image.

27. The sonar system according to claim 24 , wherein the processor is configured to generate the sonar image data by generating the sonar image data such that the second sonar return data representative of the at least one object is positioned over the first sonar return data that is representative of the at least one object within the image.