有限频与射线层析成像比较研究综述

Review on the comparative study between finite-frequency tomography and ray-theoretical tomography

从正演近似性和反演多解性两方面对有限频与射线理论的争论历史和比较研究进展进行介绍并评述.从早期的衍射层析成像开始,回顾了有限频理论的发展历史.详细介绍了2005至2006年间有限频理论的拥护者与质疑者之间的一场影响深远的争论.这场争论纠正了之前十多年许多地震学家将地震波相关走时与初至走时相混淆的错误认识,使有限频理论得到广泛认可,但有限频层析成像的实际分辨能力是否强于射线层析成像分歧很大.争论之后,有限频与射线层析成像比较研究成为一个研究方向.在体波领域,正演理论和实际反演的比较研究显示出两者有明显的差别,而合成反演实验因计算量问题没有取得突破性进展.在面波领域,正演理论、实际反演和合成反演实验都有深入的比较研究,显示两者的差别不是很大.

From the approximation of forward simulation and the non uniqueness of inversion aspects, the controversial history and review of finite-frequency theory and ray theory are introduced with comments. Beginning with the early diffraction tomography, the developing history of finite frequency theory is reviewed. The controversy between the defenders and the oppugners of finite-frequency theory from 2005 to 2006 is introduced in detail. It has a far-reaching influence. The controversy, which corrected the misconception of lots of seismologists. They confused the cross-correlation traveltime with the differential traveltime of first arrival for more than ten years and made the finite-frequency theory widely recognized. However, there were contrary opinions on whether its tomography resolution is stronger than that of ray theory. After the controversy, the comparative study between them becomes a research field. In the research of body wave, the comparison of forward theory and inversion used real data indicates that obvious differences exist, while the synthetic inversion test has got no breakthrough. In the field of surface wave research, deep study is in three aspects which indicates no significant difference between the two tomography theory.