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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2001

Earth Sciences

Boise State University

Geophysical techniques

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Full-Text Articles in Physical Sciences and Mathematics

Use Of Principal Component Analysis To Determine Down-Hole Tool Orientation And Enhance Sh-Waves, Paul Michaels Jan 2001

Use Of Principal Component Analysis To Determine Down-Hole Tool Orientation And Enhance Sh-Waves, Paul Michaels

CGISS Publications and Presentations

A common problem in down-hole shear wave surveys is the determination of the tool rotation relative to the seismic source polarization direction. This paper reports an algorithm which has been developed to solve for this angle in the horizontal plane. The method employs Principal Component Analysis (PCA) to determine the angle from the large motion of the SH-wave (not first motion). Once the angle is known, the horizontal component data may be rotated so that one component is aligned with the source polarization, and the other orthogonal to it.

Significant findings include the following. First, subtraction of oppositely polarized source …