GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 3.1 561 First, amplitude recovery and balance of shots and receivers responses, deleting parts of records strongly contaminated by noise (spikes, cross-feeds, random noise), took place at the pre-processing stage. Since WED application requires a reliable velocity field, we first proceeded to pick all first arrival times in the field records in order to perform a tomographic inversion of first breaks. We created an initial model with square cells, 25 m wide, corresponding to half receivers distance, by using a commercial software TomoPlus® (GeoTomo LLC: www.geotomo.com ). This step allowed us to build a velocity model for near-surface sequences, where significant complexities are present, like highly variable lithology and rough topography. Fig. 1 - Migrated seismic section PN. Thin lines connote horizons marking structural trends. Fig. 2 - Migrated seismic section PS. Thin lines connote horizons marking structural trends.