Many vessel-mountable sonar systems are known in the art. Examples of such systems include depth sounder(s), simple obstacle avoidance sonar(s), side scan sonar(s), mechanical scanning sonar(s), and manual pole mount(s). The display methods of these vessel-mountable sonar systems do not adequately facilitate navigation with the sonar imageries, and these systems are difficult to understand and challenging to operate while the vessel is moving. In addition, these vessel-mountable sonar systems do not have the capability to provide high definition resolution imaging from a moving platform on the vessel.
U.S. Pat. No. 7,035,166 discloses a sonar system comprising at least one sonar emitter, an array of sonar sensors configured to receive an echo from an outgoing signal generated by the sonar emitter and generate a raw data signal; at least one roll, tilt, and yaw sensor, an input from a sensor determining the latitude and longitude position of the sonar emitter; and circuitry adapted to collect the raw signal data, process the raw signal data to provide image data. The image is rotated responsively to the roll, tilt and yaw orientation of the sonar system as determined by the respective sensors. The roll, tilt and yaw sensor and image processing allows successive display of multiple images from successive transmissions to be oriented with the same fixed frame of reference in a direction relative to the earth.
U.S. Pat. No. 7,173,879 discloses a sonar system comprising a broad beam transmitter, a phased array receiver, a processor which utilizes a non-Fourier based beamformer, and correlation based processing techniques to extract valid targets from the beamformed data where the number of targets to search for is based on the values attained from an Adaptive Target Population Estimator processing technique. The values of the eigenvalues and the slope of successive eigenvalues are used to determine the number of targets to be searched for by the beamformer.
U.S. Pat. No. 7,123,546 discloses a sonar system comprising at least 2 transmitters with varying field of views, a receive system with a field of view which encompasses all the field of views generated by the transmitters, a control system designed to switch electronics between transmitters, and processing parameters set to correspond to the transmitters where the controller allows for the transmission and reception of a single ping before the next transmission, allowing each transmission to be differentiated in time.