Abstract: Disclosed vertical seismic profiling (VSP) survey systems and method acquire multi-component signal data and represent the signal data in terms of a combination of parameterized compression, shear, and dispersive wavefields. Multiples of each wavefield type may be included, e.g., to separate upgoing and downgoing wavefield components. A nonlinear optimization is employed to concurrently estimate an incidence angle and a slowness value for each wavefield. For the dispersive wavefield(s), the slowness may be parameterized in terms of a phase slowness and a group slowness with respect to a central wave frequency. The parameter values may vary as a function of depth.