| 摘要 |
<p>A method for correcting data measured by a well logging instrument (3) for effects of cable (2) yo-yo. The data are first preprocessed to reduce magnitude of spatial frequency components in the data occurring within a bandwidth of axial accelaration of the logging instrument (3) which corresponds to the cable (2). Then eigenvalues of a matrix are shifted, over depth intervals where the smallest absolute value one of the eigenvalues changes sign, by an amount such that the smallest absolute value eigenvalue does not change sign. The matrix forms part of a system of linear equations by which the measurements made by the instrument are converted to values of a property of interest of earth formations. Artifacts which may remain in the data after the step of preprocessing are substantially removed by the eigenvalue shifting.</p> |
