Method for generating multiple free seismic images

A method, including: storing, in a computer storage device, geophysical seismic data that has been separated into a multiple-free component and a multiple contaminated component; performing, with a processor, a first full wavefield inversion process on the multiple-free component of the seismic data, wherein a first subsurface physical property model is generated; determining, with a processor, an extended target reflectivity, wherein the extended target reflectivity includes a reflectivity for each of a plurality of shots; separately performing, with a processor, a second full wavefield inversion process with the multiple contaminated component of the seismic data for each of the plurality of shots using the reflectivity corresponding to each of the plurality of shots, wherein a second subsurface physical property model is generated; and generating, with a processor, multiple-free final subsurface physical property model by combining the first subsurface physical property model and the second subsurface physical property model.