LAB 05 - VELOCITY PICKING

MATLAB SCRIPT LAB 5.2

clear all,close all,clc

load SeismicData_gain_bpf_sdecon_gain_sorted_C.mat

%% Extracting CMP gathers and its semblance

cmp_step=5;

cmp_start=205;

cmp_end=255;

vmin=5000;

dv=200;

nv=51;

n_pts=8;

%% Velocity picking

[v_stack,t_stack]=vel_picking(Dsort,Hsort,vmin,dv,nv,cmp_start,cmp_end,cmp_step,n_pts);

The user will pick possible velocities by pointing and clicking the pointer on the semblance plot. The CMP gathers are also displayed along with their semblance as shown below:-

Figure 1: CMP number 205

Figure 2: CMP number 210

Figure 3: CMP number 215

Figure 4: CMP number 220

Figure 5: CMP number 225

Figure 6: CMP number 230

Figure 7: CMP number 235

Figure 8: CMP number 240

Figure 9: CMP number 245

Figure 10: CMP number 250

Figure 11: CMP number 255

The output of the M-function vel_picking.m is composed of two vectors: one containing the stacking times and the other containing the stacking velocities, where we are going to use them for NMO correction in the coming section.