Seismic Experiment

In practice the ZO shooting geometry shown in Figure 1 does not produce useful results because the signal/noise (S/N) ratio is too low. This is in part due to the very weak zero-offset reflections , strong coherent noise, and strong scattering (?) noise near the source. To suppress these noises, the seismic reflection experiment is designed to record arrivals that are offset from the source position, as shown in Figure 1.5. This figure shows a 2-D recording geometry where the source shoots into a 1-D recording line of receivers or geophones, and the resulting reflections are recorded by the recording truck. This is referred to as a 2-D recording line because the reflections are assumed to emanate only along the vertical XZ plane coincident with the recording line. The length of the recording line is sometimes referred to as a cable length.

  

Figure 1.5: Typical shooting geometry for a 2-D end-line seismic experiment, where the shot is at one end of the spread. After excitation of the shot, the stations and shot are moved by the same amount and the experiment is iteratively repeated.