Abstract:

An inverse scattering method that uses eigenfunctions of the scattering operator has been applied to obtain quantitative images of various scattering objects. The eigenfunctions of the scattering operator constitute a basis of an operator that is essentially equivalent to the time-reversal operator previously defined by others. The scattering objects span regions that are large compared to the wavelength of the acoustic illumination. Among the images are results for patterns of wires, homogeneous cylinders, and cylinders with wire inclusions. The eigenfunction method is compared to the method of filtered backpropagation implemented in each of two ways: numerical quadrature and fast Fourier transform. The results show the capability of the eigenfunction method to image objects with large ka. The results also show the eigenfunction method can be more efficient than the filtered backpropagation method when the scattering operator has few eigenvalues. [Work supported in part by NIH and USAMRMC.]