GNGTS 2021 - Atti del 39° Convegno Nazionale

GNGTS 2021 S essione 3.1 398 Numerical examples In this section, we show a synthetic example build upon the central portion of the Marmousi model, sampled every 20m. The acquisition geometry is made of 256 sources placed every 20m; in the very same positions we placed 256 receivers whose signals are modeled through a 2D FD propagation of a Ricker wavelet centered at 15Hz; the recording time is 9.6s sampled every 8ms. Finally, the direct arrivals have been removed from the data. The coarse acquisition is obtained by regularly taking 1 every 4 shots to simulate a more realistic source spacing of 80m. We first restored the 3D data time slice by time slice, then the 3D convolutional filters were introduced. Finally, we added the source-receiver symmetry constraint to the output of the network. Time slice interpolation Figure 1 shows the application of the 2Dmulti-res U-Net as deep prior to solve the regularization problem. Inparticular, Figure 1a displays the regularizedtime slice, Figure 1c displays a reconstructed common receiver gather and Figure 1d the corresponding synthesized shot gather. Whilst the result can be considered quite acceptable, it is possible to notice some alias in the reconstruction and some leakage in the residuals shown in Figure 1b. The achieved SNR is 11 . 5dB.