Abstract: A watercraft angle of attack system includes sensors having a position locator; a heading sensor; a tilt sensor; an acoustic Doppler velocity sensor that measures velocity of the boat relative to a volume of water remote from the boat so as to reduce the boat-induced disturbance of the velocity in the volume; and a processor programmed to receive real time data from the sensors; and to compute and display angle of attack of the watercraft relative to the water.

Abstract: A system for determining the directional properties of surface waves or internal waves of a fluid medium includes a sonar system having a plurality of transducers for generating respective, separate acoustic beams and receiving echoes from one or more range cells located substantially within the beams; and a computer program for determining the directional properties associated with the surface waves or internal waves from the received echoes, wherein the computer program determines along-beam velocities along the separate acoustic beams and combines the along-beam velocities to form an equivalent orbital velocity vector. The system is mounted on or in a sub surface buoy that can move or rotate during measurement and includes a motion sensor measuring six degrees of freedom to account for horizontal velocity and vertical displacement in the subsurface buoy mounted sonar system.

Abstract: A system for determining the directional properties of surface waves or internal waves of a fluid medium includes a sonar system having a plurality of transducers for generating respective, separate acoustic beams and receiving echoes from one or more range cells located substantially within the beams; and a computer program for determining the directional properties associated with the surface waves or internal waves from the received echoes, wherein the computer program determines along-beam velocities along the separate acoustic beams and combines the along-beam velocities to form an equivalent orbital velocity vector. The system is mounted on or in a sub surface buoy that can move or rotate during measurement and includes a motion sensor measuring six degrees of freedom to account for horizontal velocity and vertical displacement in the subsurface buoy mounted sonar system.

Abstract: A system for determining the directional properties of surface waves or internal waves of a fluid medium includes a sonar system having a plurality of transducers for generating respective, separate acoustic beams and receiving echoes from one or more range cells located substantially within the beams; and a computer program executed by a processor for determining the directional properties associated with the surface waves or internal waves from the received echoes, wherein the computer program determines along-beam velocities along the separate acoustic beams and combines the along-beam velocities to form an equivalent orbital velocity vector.