| abstract |
Beam forming is performed at high speed and with high accuracy without performing approximate calculation. The method includes a step (a) of receiving a wave coming from a measurement object by a reception aperture element to generate a reception signal, and beam forming by performing Fourier transform and wave number matching on the reception signal. (B) performing processing, wherein step (b) is obtained by multiplying the received signal by Fourier transform with respect to the axial direction by a complex exponential function expressed using the wave number and imaginary unit of the wave. Wave number matching is performed, and the product is subjected to Fourier transform in the horizontal direction, and the obtained calculation result is multiplied by the first complex exponential function, and at the same time by multiplying the second complex exponential function, wavenumber matching in the axial direction is performed, Image signal directly in Cartesian coordinate system by performing wave number matching without interpolation approximation process Including that generated. [Selection] Figure 2 |