Active source experiment (MASW)

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General overview

First introduced by Al-Husseini et al. (1981), Mari (1984), Gabrielset al. (1987), the Multichannel analysis of surface waves was popularized by Park et al. (1999). This technique relies on the recording along a 1D linear profile of seismic signals produced by a controlled source (hammer, vibrator, explosion, etc.) and analysis of surface wave dispersion properties after applying slant-stack or FK transform to the recorded seismic section. In the following tutorial, only the FK transform is used.

Getting ready

Exemple of a seismic section.
  • Download the compressed signal file.
  • Launch Geopsy and set Rxxx as name in the Geopsy Loading Preferences.
  • Load and view these downloaded signals. A seismic section as the one displayed in the figure on the right should then appeared.
  • Open the MASW toolbox by pushing the following plugin icon MASWToolboxPluginIcon.png or, alternatively, by selecting Linear F-K for active experiments in Tools menu.

Checking sources and receivers location

  • Edit headers if needed
  • cross-link avec table, set headers

Description of the MASW toolbox

  • difference entre taper et processing window
  • HRFK (cross-link avec HRFK de Mathias)
  • normalize energy

FK Computing

  • computation for one single file and picking of the curve
  • alternatives : 1) create a stack file and then compute the FK; 2)compute FK for all shots and then stack the FK maps