Abstract : In this paper, we present two frequency-domain algorithms for 2D imaging in solids, namely Stolt's method and Lu's method, the latter being extended to the 3D imaging with matrix arrays. First, the performances of both frequency-domain methods are evaluated in 2D imaging and compared with the time-domain plane wave imaging (PWI). Then, Lu's method and PWI are applied to 3D to image a distribution of small porosities in a steel block. 2D and 3D images calculated with the f-k methods are comparable to the PWI images in terms of contrast and spatial resolution while achieving computation times more than 25 times shorter.
