Geopsy: Tools

Tools menu

Geopsy software provides powerful tools for advanced signal processings, for instance ambient vibration array processings or H/V spectral ratio. A plugin mechanism allows you to install only selected tools corresponding to your need. Through the menu Preferences it is possible to add (or remove) new tools without upgrading the main Geopsy frame.

The advanced signal processings tools are available under the menu Tools or directly by clicking on the icons in the toolbar.

For all the tools, the data can be processed:

• from a graphic viewer, to verify the windowing and to display the results;
• from a table. In this case, Geopsy will display only the resulting curves.

The following tools are available:

Advanced signal processing tools

• F-K : conventional frequency wavenumber technique
• High resolution F-K : high resolution frequency wavenumber technique
• MSPAC : modified spatial autocorrelation technique
• Linear F-K for active experiments : multichannel analysis of surface waves (MASW)
• Linear FK for passive experiments : multichannel analysis of surface waves for ambient vibrations
• Damping : computation of damping factor for soil or structure
• Spectrum : Fourier amplitude spectra
• Spectrum Rotate : Fourier amplitude spectra as a function of azimuth in the horizontal plane
• H/V spectral ratio : Horizontal-to-Vertical spectral ratio
• H/V Rotate : Horizontal-to-Vertical spectral ratio as a function of azimuth in the horizontal plane
• Shot stacks: improvement of signal-to-noise ratio for refraction/MASW shots
• Particle motion: plots particle motion on various planes
• Refraction with NA: obsolete
• Time frequency analysis
• Structure Spectrum

Plugins

The advanced signal processing tools belong to plugins that are organized as follow:

• Plugin geopsyhv which contains
  • H/V spectral ratio
  • H/V rotate
  • Spectrum
  • Spectrum rotate

• Plugin geopsyarray which contains
  • conventional frequency wavenumber technique F-K
  • High resolution frequency wavenumber technique HRFK
  • modified spatial autocorrelation technique MSPAC
  • multichannel analysis of surface waves for active and passive experiments

• Plugin structureratio which contains
  • Structure spectrum

Each tool, identified by a PLUGIN name and a SLOT number, can be run from command line interface

-tool <PLUGIN> -slot <SLOT>             

Example

 geopsy -db /home/user/MyDatabase.gpy -tool geopsyhv -slot 1
        -group "MyGroup" -- -param tmp.log -autowin -peaks
        -clearpeaks -addpeak "4,6" -peaks

Open the database "MyDatabase.gpy" and start H/V processing on group of signals named "MyGroup"'. Automatic windowing is used. Parameters specific to HV processing are defined only after '--'. Omitting it, you will get error messages like this, geopsy assuming that those non-standard parameters are signal files to load.

Cannot determine byte order for SU format.
Cannot determine byte order for SEGY format.
Cannot determine byte order for PASSCAL SEGY format.
----WARNING--- Loading signal ...----
Unknown format for tmp.log
geopsy: no signal available, check options -file, -db or -group, see -h for help

Parameters are defined by "tmp.log". The default peaks are printed. Then, the list of peaks is cleared and a new one is added between 4 and 6 Hz.

For a complete description of the plugin options see the man pages.

Tools debug option

As said previously the plug-in tools can be managed in the menu Preferences. Additionaly, options for tool debugs are also available from command line interface :

 -debug-stream             // Debug mode (redirect all logs to stdout)
 -clear-tools              // Reset to default tool list
 -debug-tools              // Test available tools and exit
 -add-tool-path <PATH>     // Add PATH to the list of paths to search for tools