Geogiga Surface - Version 9.3 -Active Surface Wave Data Analysis

Data input

• Import all seismic records of a survey line at one time
• Efficiently assign geometry measured with slope or horizontal distance
• Input elevation data
• Optionally load dispersion curves together with seismic data for reprocessing

Dispersion curve picking

• Mute noise and select traces for dispersion analysis
• Test apparent velocity of surface waves on traces
• Set frequency range with amplitude spectrum
• Incorporate elevation data in dispersion analysis
• Extract dispersion curves with MASW or SASW
• Generate dispersion images in F-K, F-V, or F-P domain
• Interactively or semi-automatically pick dispersion curves with a spectrum graph

Inversion

• Automatically or interactively build an initial model
• Specify Poisson's ratio and density for each layer
• Fix any layers in inversion
• Invert dispersion curves with genetic algorithm (GA)
• Allow simultaneous inversion of shear wave velocity and layer thickness
• Optionally constrain the inversion by the trend of initial model
• Support fundamental and higher modes of Rayleigh and Love waves
• Automatically invert dispersion curves of all records at a time
• Interactively pause and resume, or stop the inversion procedure

Plotting

• Plot dispersion curves and velocity models
• Display velocity sections with colours, contours, and editable lithologic symbols
• Trim velocity section based on the depth of bottom layer
• Plot well data
• Simultaneously display dispersion curves and velocity section

Output

• Apparent Vs, Vs30 (or Vs100), depth-weighted velocities, and SPT-N values
• Velocity section with a blanking file