Seismic applications > Dispersion Analysis with OBS data

We present common receiver sections obtained with the following parameters:

  • The maximal offset between source and receivers: 900 m;
  • The listening time is of 1s;
  • The time sampling: 2 ms;
  • The spatial sampling: 50 m.

For the selected component (hydrophone or geophone X, Y, Z), the figure shows from left to right:

  • The seismic section. The guided wave is dominant;
  • A decreasing of amplitude of the seismic signal (mainly the guided wave), according to the distance source-sensor;
  • The f-k image.

We will notice the very strong aliasing of the guided wave. This phenomenon is clearly visible on the f-k plot. As for the dominant wave, flattening data by applying a velocity correction compensates the aliasing phenomenon. We can notice that the energy associated to the guided wave is not centred on the null wave number in plan "frequency-number of wave". This points out that the guided wave is dispersive.