Estimating the Covariance of a Velocity Field Accounting for a Linear Vertical Gradient

C-32 ESTIMATING THE COVARIANCE OF A VELOCITY FIELD ACCOUNTING FOR A LINEAR VERTICAL GRADIENT. GERAETS D. 1 GALLI A. 1 and RUFFO P. 2 1 École des Mines de Paris 35 rue Saint Honoré F- 77 305 Fontainebleau 2 ENI Agip Division Via Emilia 1 20097 San Donato Milanese Abstract The estimation of the covariance model of the velocity field is of primary interest in geophysics : this parameter is required to obtain velocity fields optimally combining data from various sources but also to estimate the attenuation and dispersion of waves propagating through random media. Here we recall how this