The idea of synthesizing a line seismic source from individual shot records is not new. Imaging or processing based on wavefront synthesis has been considered since the earliest seismic exploration. Taner 1976 proposed synthesizing plane-wave sources at the surface by stacking traces in a common receiver gather. Claerbout 1976 proposed target-oriented wavefront synthesis as a robust migration scheme through regions of strong lateral velocity variation. Schultz and Claerbout 1978 presented the wave stack concept that is fundamental to the wavefront synthesis and explained how to use it for velocity analysis by synthesizing slanted plane waves. Recently, Rietveld et al. 1992 presented a successful application of the wavefront synthesis method to the well-known Marmousi data set.