In search of the vibroseis first arrival

The first step in correcting for time delays of land seismic data due to low-velocity weathered layers is to pick the first-arrival times of the refracting energy. But doing so for vibroseis data can be difficult, as the seismic wavelet is often ringy and uncompact, resulting in cycle-skipped picks. Even when we manage to pick a waveform feature consistently, it is not clear where the first-arrival time is in relation to it. I present a novel method that shapes the seismic wavelet to a Ricker wavelet whose peak is located at the true arrival time, so the time of the first arrival is unambiguous. Further, the arrivals are less ringy and their energy more focused, so that they are less likely to cycle skip or be overwhelmed by random noise. The result is more accurate and consistent first-arrival picks.