Automated, six-component, single-station ground-roll identification and suppression by combined processing of translational and rotational ground-motion

We present a new method to automatically identify and extract surface waves based on the characteristic ground motion that is exhibited by their arrival at a single recording station that is capable of yielding translational as well as rotational motion (6C station). Taking into account the rotational part of ground motion in addition to the translational part, allows one to extend the rank of the coherency matrix that is conventionally used in three component (3C) seismic polarization analysis. As a result, the ground-roll can be fully parameterized in terms of its propagation velocity, propagation direction and ellipticity, even if more than one wave-type is present in the analysis window. The resulting ground-roll polarization model can subsequently be used to remove the ground-roll while preserving the underlying reflection signal.