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Archivio digitale delle tesi discusse presso l’Università di Pisa

Tesi etd-12292020-142356


Tipo di tesi
Tesi di laurea magistrale
Autore
BALESTRI, MATTIA
URN
etd-12292020-142356
Titolo
Full waveform inversion (FWI) a due griglie tramite algoritmi genetici di onde superficiali per modelli 1D e 2D
Dipartimento
SCIENZE DELLA TERRA
Corso di studi
GEOFISICA DI ESPLORAZIONE E APPLICATA
Relatori
relatore Prof. Stucchi, Eusebio Maria
correlatore Dott. Pierini, Silvio
Parole chiave
  • 2D finite difference modelling
  • genetic algorithm
  • surface wave
  • two-grid FWI
Data inizio appello
29/01/2021
Consultabilità
Completa
Riassunto
In this thesis a two-grid Full Waveform Inversion (FWI) of surface waves (Rayleigh) is proposed for the estimation of 1D and 2D models of shear wave velocity (Vs). One of the main objectives was the parametrization setting for the optimization technique considered. The aim was to obtain a tool capable of making qualitatively and quantitatively valid estimates of increasingly complicated models, within reasonable computational time.
Keeping an initial information content as limited as possible, three models with an increasing level of complexity were considered; this allowed us to test the robustness of our optimization process. Therefore, starting from a 1D synthetic case, good results are also achieved for a real-like model, improving the results of previous works. This has therefore made it possible to obtain information on the reliability of this type of inversion, giving indications on the acquisition geometry to be used, grid parameter setting, computation time and strategy to adopt in the inversion procedure (frequency marching and offset stripping) to obtain a good estimate of the characteristics of the subsoil.
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