垂向非均匀背景多频背向散射层析成像

MULTIFREQUENCY BACKSCATTERING TOMOGRAPHY IN A VERTICALLY VARYING BACKGROUND

相对于单频衍射层析成像而言，垂向非均匀背景多频背向散射层析成像方法大大提高了图像的分辨率和质量；其计算速度比其它诸如多频全息术、叠前偏移等多频方法快得多；用反传播进行成像时，该方法的计算速度与有关文献提出的均匀背景相应的方法几乎相同，但该方法适用于垂向非均匀背景，因而更适于实际应用．本文还提出了垂向非均匀背景中空间域Ｂｏｒｎ散射数据的一种快速形成方法．

Compared to a single-frequency diffraction tomography,the multifrequncy backscattering tomography(MFBT) in a vertically varying background improves greatly 1)Present address:Departement de Sismologie,Institut de Physique du Globe de Paris,4,Place Jussieu,F-75252 Paris Cedex 05, France the resolution and quality of images.The computation speed of the approach is much faster than other multifrequency methods such as multifrequency holograPhy,pre-stack migration,etc.It is more practical than the MFBT in a homogeneous background proposed by the literature and its computation speed by backpropagation is almost the same as that of the method in the literature.We have also presented a method of generating the Born scattered wave fields in spatial domain for a vertically varying background.