Suppressing non‐Gaussian noises with scaled receiver wavefield for reverse‐time migration: comparison of different approaches

Abstract

A B S T R A C TNumerical implementation of the gradient of the cost function in a gradient-based full-waveform inversion (FWI) is essentially a migration operator used in wave equation migration. In FWI, minimizing different data residual norms results in different weighting strategies of data residuals at receiver locations prior to back-propagation into the medium. In this paper, we propose different scaling methods to the receiver wavefield and compare their performances. Using time-domain reverse-time migration (RTM), we show that compared to conventional algorithms, this type of scaling is able to significantly suppress non-Gaussian noise, i.e., outliers. Our tests also show that scaling by its absolute norm produces better results than other approaches.

On a plane-wave based crosscorrelation-type seismic interferometry

“…In comparison, however, with the plane-wave domain approach, we can suppress the noises in the CPG gather (Figure 10d). We believe this approach can perform better not only for pure random noise, but also for fractal noise (Tao and Sen, 2012) and outlier noise (Tao and Sen, 2013b), etc. We applied our approach to one line of ocean-bottom seismometer (OBS) survey across Taiwan and the western Philippine Sea (McIntosh et al, 2005).…”