 clear;
% ------------------------------------------------------------------------- %
%                                                                           %
%                                                                           %
%                 Script for constant velocity scans                        %
%                                                                           %
%                  M.D.Sacchi - for Geoph 326 - UofA                        %
%                                                                           %
% ------------------------------------------------------------------------- %
 

% ------------------
% 1 - INPUT DATA
% ------------------
 
% Read synthetic gather (gather is in ./codes/SeismicLab_data)

 [D,H] = readsegy('syn_cmp_mult.su');
 h = [H.offset];
 dt = H(1).dt/1000/1000;
 [nt,nh] = size(D);

% ------------------------------------------------------------------------
% 2 - Compute a velocity axis and apply constant v NMO for each velocity
% ------------------------------------------------------------------------

 vmin = 1200;
 vmax = 3200;
 nv = 21;

 vnmo = linspace(vmin,vmax,nv);
 tnmo = [0];     % any number since this is constant velocity NMO
                 % same velocity is used for all the time axis 

 Max_Stretch = 40;

% Save velocity scans in Scans

 Scans = [];

  for k = 1:nv
   temp = nmo(D,dt,h,tnmo,vnmo(k),Max_Stretch);
   Scans = [Scans, temp];
  end;


% ----------------------------------------------------------
% 3 - Display Scans
% ----------------------------------------------------------

 
 taxis = [0:1:nt-1]*dt;
 figure(1); clf; 
 plot_scans(vnmo,taxis,Scans);
 ylabel('t [s]');
 title('Constant Velocity Scans');


