Paper Summary
In land multi-component (MC) data processing, the orientation of each receiver's horizontal components in the field (H1 and H2) is seldom known accurately. Methods to derive the orientations from recorded data are in common use. They work by assuming a homogeneous, isotropic near-surface earth model and derive an orientation using Pwave first arrival amplitudes on the horizontal components. These methods are known to work well on marine OBC/OBN data and down-hole VSP data. For land data, the near-surface is often strongly inhomogeneous and anisotropic. The P-wave first-break methods can therefore yield inaccurate results. We show examples that illustrate the deviation of P-wave first-break amplitudes from what is expected from a homogeneous near-surface earth.
