Seismic wavefield modeling honoring AVO/AVA with applications to full waveform inversion and least-squares imaging

A computer program stored in a non-transitory computer readable medium, the program having logic operable to cause a programmable computer to perform a process for generating a subsurface image of elastic wave propagation property parameters for seismic exploration, the process comprising:

• calculating expected seismic signals based on an arrangement of at least one seismic source and at least one seismic receiver and based on an initial model of Earth's subsurface, the at least one seismic source and the at least one seismic receiver disposed proximate a volume of subsurface to be analyzed, the initial model comprising spatial distribution of at least one parameter related to propagation of elastic waves in subsurface formations in the volume, the calculating comprising entering the initial model into an acoustic wave equation modified by at least one secondary source term, the at least one secondary source term used to estimate amplitude versus offset and/or angle (AVO/A) phenomena in the calculated expected seismic signals, the acoustic wave equation requiring modification by the at least one secondary source term to perform the estimation;
• comparing the calculated expected seismic signals with measured seismic signals obtained from the at least one seismic sensor in response to actuating the at least one source;
• determining differences between the calculated seismic signals and the measured seismic signals;
• using an inversion method to adjust the initial model and repeating the calculating, comparing and determining until the differences fall below a selected difference limit to generate a final model of spatial distribution of the at least one parameter;
• and
• generating an image of the spatial distribution of the at least one parameter using the final model.