Vector Domain P and S decomposition in viscoelastic media

P and S decomposition is an essential step in isotropic viscoelastic reverse time migration (VRTM). Separation using divergence and curl operators doesn't preserve the phase or amplitude of the input viscoelastic wavefield, so an alternative decomposition that preserves the vector components of the P- and S-waves in the input wavefield is desired. With a decoupled assumption, we rearrange the memory variables in the elastodynamic equations based on the standard linear solid. The vector components of the propagating P- and S-wave can be can be decomposed in isotropic viscoelastic media without losing accuracy. Synthetic tests show that the P- and S-waves can be decomposed with no distortion of the amplitude or phase, and have the same vector components of particle velocity that exist in the viscoelastic wavefield before decomposition.