LAUSR

Simultaneous shooting offers opportunities for significant cost savings in seismic data acquisitions. The most common strategy uses random delay shots where source separation is achieved during the processing stage, thereby doubling source densities. We demonstrate that the creation of a collocated source survey, where shots are repeated simultaneously at multiple positions, is a viable alternative strategy, with the additional benefit that it may increase source density even further while keeping the acquisition duration unchanged. Source separation is achieved using overcomplete independent component analysis by first applying a directional wavelet transform to separate source signals with different slownesses, estimating the mixing matrix, followed by solving an optimization problem with an energy constraint combined with a sparseness-inducing prior to obtain the required waveforms. Synthetic tests show average reconstruction quality on the order of 22.1 dB, 15.4 dB and 8.4 dB if respectively 3, 4 or 5 shots are acquired in two mixtures. Examination of the true versus obtained zero-offset sections also demonstrate the robustness of the proposed signal recovery strategy. The advantage of shot collocation over conventional acquisitions is that it may triple or even quadruple the source density for unchanged acquisition durations with superior reconstruction results compared to dithered acquisitions using similar blending factors.