固体物理模型井间数据层析成像

TOMOGRAPHY FOR CROSSWELL DATA FROM SOLID MODELS

Until recently, applied examples of tomography have worked with crosshole data which were collected from physical models with water as medium, in which the velocity contrast between the background and anomalous body is so low that the straight ray hypothesis appear to be acceptable in back projection reconstruction process. This paper will study the tomography for crosswell data from a model with solid medium, in which the velocity contrast goes up to 46%. In this case, the straight ray hypothesis is no longer valid and the fact of curved rays has to be honoured in reconstruction process. Some results obtained as a consequence of incorperating both SIRT and LSQR techniques for the reconstruction of a tapered and a fault models are given in the paper as well. In addition, the paper further discusses a number of factors that have influence on the quality of image reconstruction in tomography.