Abstract: Computing device, computer instructions and method for determining an image of a surveyed subsurface. The method includes receiving recorded wave fields D recorded with seismic sensors over the subsurface; generating a series of modified recorded wave fields Dn based on the recorded wave fields D; iteratively applying an objective function Fi to (1) one element Di of the series of modified recorded wave fields Dn and (2) predicted wave fields Pmi, where “i” is an index associated with a given iteration; calculating with a computing device an updated velocity model mi+1 based on a previous velocity model mi and a step length; and producing the image of the subsurface based on the recorded wave fields D and the updated velocity model mi+1. The predicted wave fields Pmi are predicted by the previous velocity model mi.

Abstract: Computing device, computer instructions and method for determining an image of a surveyed subsurface. The method includes receiving recorded wave fields D recorded with seismic sensors over the subsurface; generating a series of modified recorded wave fields Dn based on the recorded wave fields D; iteratively applying an objective function Fi to (1) one element Di of the series of modified recorded wave fields Dn and (2) predicted wave fields Pmi, where “i” is an index associated with a given iteration; calculating with a computing device an updated velocity model mi+1 based on a previous velocity model mi and a step length; and producing the image of the subsurface based on the recorded wave fields D and the updated velocity model mi+1. The predicted wave fields Pmi are predicted by the previous velocity model mi.