Full Waveform Inversion with Multisource Frequency Selection

Multisource Full Waveform Inversion (FWI) of phase-encoded supergathers has shown great promise in reducing the computational cost of conventional FWI. But for land- or marine-streamer acquisition geometry this approach faces the challenge of erroneous misfit due to the mismatch between the limited number of live traces/shot recorded in the field and the pervasive number of traces generated by the finite-difference modeling method. To tackle this mismatch problem, a key enabling frequency selection strategy is described: At each FWI iteration, we assign a unique frequency band to each shot gather, so that the spectral overlap among those shots¿and therefore their crosstallk¿is zero. Consequently, each receiver can unambiguously identify and then discount the superfluous sources¿those that are not associated with the receiver in the streamer acquisition. This strategy allows significant speedup of FWI.