Methods and apparatuses for constructing a 3d sonar image of objects in an underwater environment

An apparatus comprising a sonar signal processor and a memory including computer program code, the memory and the computer program code configured to, with the sonar signal processor, cause the apparatus to:

• generate a 3D matrix based on sonar return data received from an underwater environment, wherein the 3D matrix comprises a plurality of sonar returns defined by 3D positional values;
• determine, based on the 3D positional values of each of the sonar returns, one or more groups of sonar returns among the plurality of sonar returns in the 3D matrix associated with one or more objects in the underwater environment, wherein the one or more objects are different than a bottom surface of the underwater environment, wherein the determination of the one or more groups of sonar returns associated with the one or more objects in the underwater environment comprises:
• generating, based on the 3D positional values of each of the plurality of sonar returns, a 3D representation of all of the plurality of sonar returns in the 3D matrix such that each of the plurality of sonar returns defines an x coordinate, a y coordinate, and a z coordinate;
• and
• determining one or more clusters among the plurality of sonar returns in the 3D representation, wherein the one or more clusters among the plurality of sonar returns in the 3D representation each comprise sonar returns that are within a threshold distance of each other within the 3D representation;
• and
• generate a 3D image of the one or more groups of sonar returns associated with the one or more objects in the underwater environment.

A computer program product comprising a non-transitory computer readable medium having program code portions stored thereon, the program code portions configured, when said program product is run with a sonar signal processor, to:

• generate a 3D matrix based on a sonar return data received from an underwater environment, wherein the 3D matrix comprises a plurality of sonar returns defined by 3D positional values;
• determine, based on the 3D positional values of each of the plurality of sonar returns, one or more groups of sonar returns among the plurality of sonar returns in the 3D matrix associated with one or more objects in the underwater environment, wherein the one or more objects are different than a bottom surface of the underwater environment, by:
• generating, based on the 3D positional values of each of the plurality of sonar returns, a 3D representation of all of the plurality of sonar returns in the 3D matrix such that each of the plurality of sonar returns defines an x coordinate, a y coordinate, and a z coordinate;
• and
• determining one or more clusters among the plurality of sonar returns in the 3D representation, wherein the one or more clusters among the plurality of sonar returns in the 3D representation each comprise sonar returns that are within a threshold distance of each other within the 3D representation;
• and
• generate a 3D image of the one or more groups of sonar returns associated with the one or more objects in the underwater environment.