Patent ID: 8717847

Claim:
Sonar apparatus for mounting on a boat, comprising: at least one transmitter operable to transmit sound waves for reflection from points on the underwater floor in front of the boat; a plurality of one-dimensional arrays of receiving transducers, comprising a respective array for each of a plurality of segments of water in front of the boat, each array of receiving transducers being responsive to received sound waves reflected from points on the underwater floor within the respective associated segment of water in front of the boat to produce electrical signals, wherein the one-dimensional arrays of receiving transducers are arranged in a plurality of housings configured to be mounted on the port and starboard sides of the boat, and wherein each housing contains at least two one-dimensional arrays of receiving transducers, with the arrays mounted at a predetermined angle relative to each other so as to receive reflected sound waves from different respective segments of the water in front of the boat that are separated from each other in a horizontal plane; a feature locator operable to process the electrical signals from each respective array of receiving transducers to calculate three-dimensional positions of reflecting points on the underwater floor within the segment of water associated with the array of receiving transducers; an interpolator operable to calculate from the three-dimensional positions of the reflecting points within the segments calculated by the feature locator, three-dimensional positions of points on the underwater floor in front of the boat between the segments; and a display data generator operable to process the three-dimensional positions of the points to generate image data for display showing the underwater floor in front of the boat.