function time_spread(RG,RG2)
%
tau2=1; dtau=RG.y(2)-RG.y(1);
figure
[ntau,nx,nz]=size(RG.data);
[dbmax,jtau_max]=max(RG.data);
jtau2=min(ntau,jtau_max + floor(tau2/dtau));
db_axis=dbmax - RG.data(jtau_max:jtau2,:,:);
tau_axis=RG.y(jtau_max:jtau2) - RG.y(jtau_max);
h1=plot_cfill(db_axis,tau_axis,'none','r',4,'-',2);
hold on;
xlabel('Level - dB'); ylabel('Time Spread - s'); 
plot_size(gca,'in',4,2); plot_set3(gca,1.5,'Arial',14,1);
set(h1,'LineWidth',2);
grid on;
%
if nargin>1,
[ntau,nx,nz]=size(RG2.data);
[dbmax,jtau_max]=max(RG2.data);
jtau2=min(ntau,jtau_max + floor(tau2/dtau));
db_axis=dbmax - RG2.data(jtau_max:jtau2,:,:);
tau_axis=RG2.y(jtau_max:jtau2) - RG2.y(jtau_max);
plot_cfill(db_axis,tau_axis,'none','b',4,'-',2);
end
%
axis tight
%
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% Applied Research Laboratories, The University of Texas at Austin
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