Separation of upgoing and downgoing wavefields using the boundary element method

Summary The boundary element method has been applied for decomposing seafloor measurements into upgoing and downgoing waves. Two complementary solutions in the forms of a linear matrix system and a multiple multipole expansion are obtained without any assumptions about the subsurface. If the elastic parameters below the seafloor are known, these solutions are explicit. They do not require any knowledge of the source signature. Basic components—such as Green’s function computation—can be replaced by alternative acoustic or elastic solutions. Results are useful for deghosting, free‐surface multiple attenuation and P / S splitting of ocean‐bottom cable data.