| 摘要 |
PROBLEM TO BE SOLVED: To three-dimensionally measure the flow velocity of a reflection body with a different flow velocity by performing Fourier transformation of a received signal obtained from a plurality of elements which are two-dimensionally arranged and further performing projection processing on a flat surface. SOLUTION: A partial element V of transducer elements Q which are two- dimensionally arranged is driven, pulse-shaped sound waves at transmission intervals of T are transmitted, and a reflection signal at a point P of the reflection body is transmitted by elements q(m,n). By observing the signal in a time S from the transmission, observation times t=p.T+S immediately after transmitting p-th signal are obtained. A reflection signal s(p,m,n) at the time(t) is transmitted by the elements Q and is digitized to C(p,m,n) by an A/D converter. Further, an output which is subjected to differential processing by a filter is set to d(p,m,n) and is subjected to one-dimensional Fourier transformation to obtain an output DR1 (m,n,w). It is integrated 1, 2 to obtain a projection in the directions of gradients x andλ, thus obtaining a final output DR3 (m,x,λ). Then, a value obtained by calculation is shown on a display as a three- dimensional polar coordinate space. |
