| 摘要 |
A method of constructing a basis of functions intended for the building of approximations of one-way or two-way seismic traveltime versus offset functions. The method is characterized by the combination of the following steps of (a) creating a distribution of reference one-way or two-way traveltime versus offset functions by traveltime modelling in a set of velocity models representing possible velocity distributions, (b) obtaining new reference functions by modifying these reference traveltime functions by applying an operator to them, (c) selecting a set of discrete offsets to make these new reference functions discrete, (d) arranging these discrete functions in columns to form a matrix, (e) applying a singular value decomposition to this matrix, with singular values sorted in decreasing order, to express its columns as linear combinations of the columns of an orthogonal matrix, and (f) building the basis functions by interpolating the columns of the orthogonal matrix. |
