Patent ID: 7352651
Filing Date: 2008-04-01
Classification: G01C,G01S

Abstract:
1. A system for determining the directional properties of surface waves or internal waves of a fluid medium, comprising: 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, the plurality of transducers including an Acoustic Surface Tracking (AST) transducer for generating acoustic beams and receiving echoes for making AST measurements; a computer program executed by a processor for a) determining, based on the AST measurements, the distance from the system in the fluid medium to a free surface of the fluid medium and an ideal horizontal plane near the free surface of the fluid medium from which to determine the directional properties of surface waves or internal waves of the fluid medium; b) determining the directional properties associated with the surface waves or internal waves from the received echoes; c) determining along-beam velocities along the separate acoustic beams; and d) combining the along-beam velocities to form an equivalent orbital velocity vector at a central location over the AST transducer in the ideal horizontal plane determined by the AST measurements.