Patent ID: 8125849

Claim:
An apparatus for determining the flow of water across a cross-section of a body of water, comprising: a housing; a depth transducer mounted in said housing and directed substantially vertically towards a bottom of the body of water; and a plurality of profile transducers mounted in said housing proximate to said depth transducer, said plurality of profile transducers directed downward at an angle relative to said depth transducer, said plurality of profile transducers facing different directions, and wherein said profile transducers produce an acoustic signal having a profile beam of a profile frequency and wherein a Doppler frequency shift corresponding to the velocity of a volume of water relative to the transducer is derived from a returned profile echo from said volume of water, wherein said depth transducer produces an acoustic signal of a depth frequency lower than said profile frequency with a depth beam wider than said profile beam, and wherein a depth corresponding to the distance between said depth transducer and said bottom of the body of water is derived from a returned depth echo from said bottom of the body of water, and wherein at least a portion of said depth beam is coincident with a measured volume of water of the cross-section of the body of water.