Waveform inversion by multiple shot-encoding for non-fixed spread geometries

Seismic data processing methods and computing systems are presented. In one embodiment, a method is disclosed that includes simulating a set of simulated seismic data from a set of acquired seismic data; separating the simulated seismic data into a plurality of data sets, wherein one set of data is matched in the acquired seismic data and one set of data is unmatched in the acquired seismic data; conforming the simulated seismic data and the acquired seismic data to one another using separated, simulated seismic data unmatched by a counterpart in the acquired seismic data from the acquired seismic data; and performing an inversion between the acquired seismic data and the separated, simulated seismic data after they are conformed to one another.