DECOMPOSITION OF MULTICOMPONENT SEA-FLOOR DATA INTO UPGOING AND DOWNGOING P- AND S-WAVES

A method for decomposing multicomponent seafloor measurements into upgoing and downgoing P-and S-waves is presented. We assume that a marine survey employing a marine source in the water layer is conducted over a plane-layered medium. From recordings of the pressure just above the sea floor and the particle velocity vector just below the sea floor, decomposition filters can be determined by plane-wave analysis. The decomposition filter coefficients depend on the P- and S-wave velocities and the density at the sea bottom. We show how to decompose the multicomponent measurements into upgoing and downgoing P- and S-vertical traction components, vertical-particle velocity components, and horizontal particle velocity components. The decomposition filters are applied with good results to synthetic data modeled in a plane-layered medium.