Abstract: Recorded seismic data are obtained at a plurality of receivers from a plurality of sources, and a set of sources from the plurality of sources is selected using spatial criteria based on a location of each source such that any two sources in the set of sources are separated by a predefined minimum distance of separation sufficient to reduce cross talk between sources. The set of sources is combined in a non-encoded manner into a composite source, and forward modeling for the composite source is performed to generate a synthetic seismic data set. A composite recorded seismic data set for the set of sources is determined, and the synthetic seismic data set and composite recorded seismic data set are used to determine a residual seismic data set. Backward modeling generates a gradient update used to generate an updated earth model.

Abstract: Recorded seismic data are obtained at a plurality of receivers from a plurality of sources, and a set of sources from the plurality of sources is selected using spatial criteria based on a location of each source such that any two sources in the set of sources are separated by a predefined minimum distance of separation sufficient to reduce cross talk between sources. The set of sources is combined in a non-encoded manner into a composite source, and forward modeling for the composite source is performed to generate a synthetic seismic data set. A composite recorded seismic data set for the set of sources is determined, and the synthetic seismic data set and composite recorded seismic data set are used to determine a residual seismic data set. Backward modeling generates a gradient update used to generate an updated earth model.

Abstract: Iterative inversion of composite source data obtains recorded seismic data at a plurality of receivers from a plurality of sources. A selected orthogonal function is applied to a set of sources selected from the plurality of sources to identify candidate sources in the set of sources to receive a time shift. A time shift is applied only to the candidate sources, and all sources in the set of sources are combined into a composite source. A current earth model performs forward modeling for the composite source to generate a synthetic seismic data set. A composite recorded seismic data set associated with the set of sources at the receivers is determined and is used with the synthetic seismic data set to determine a residual seismic data set. The current earth model performs a gradient update that is used to update the current earth model and generate an updated earth model.