Automatic time-picking of first arrivals on large seismic datasets

Joe Wong

Fast, automatic procedures are required for picking first-arrival times in high-resolution 3D datasets with more than 108 seismograms. I present a procedure based on a modified energy ratio (MER) attribute that is effective for identifying the first-break times of arrivals with signal-to-noise ratios greater than 3. For arrivals with lower SNR values, the procedure exploits spatial coherence and trace semblance on common-source gathers to obtain reasonably reliable picked times. Running median filters are effective in removing outlier picked times. The report shows examples of first-arrival picking on common source gathers from a 3D survey.