rectime.m

Univ. of Calgary CREWS的免费地震研究软件

function [diffmat]=rectime(rtrange,rtpair1,rtpair2,fbcoord,shotcoord,fbtime,mint,nshots)
% Function determining the reciprocal time difference between two shot
% Difference between the arrival time value of the shot (i) at the shot (j)
% location and the arrival time value of shot (j) at the shot (i) location  
% nshots = number of shots 
% nrecs = number of receivers 
% fbcoord = receiver location (nshots,nrecs)
% fbtime = refracted arrival matrix (nshots, nrecs)
% shotcoord = shot location vector (nshots)
% function diffmat = rectime(nshots, nrecs, fbcoord, fbtime, shotcoord)
% Output: diffmat = matrix of reciprocal time differences for all the 
% possible shot pairs (nshots x nshots)

diffmat=NaN.*ones(nshots, nshots);
% Reciprocal time difference for all the possible shot pairs
if( rtrange==0)
	for i=1:nshots-1;       % i is the first shot (t1)
          fprintf(1,'rectime: processing shot %d\n',i);
	  for j=i+1:nshots;    % j is the 2nd shot (t2)
	    t1 = NaN;
	    t2 = NaN;
            validti = find(~isnan(fbtime(i,:)));
            validtj = find(~isnan(fbtime(j,:)));	
	    if (length(validti)>0 & length(validtj)>0)
              if( (shotcoord(j)>=min(fbcoord(i,validti))) & (shotcoord(j)<=max(fbcoord(i,validti))) )
	        t1=interp1(fbcoord(i,validti),fbtime(i,validti),shotcoord(j),'linear');
	      end
              if( (shotcoord(i)>=min(fbcoord(j,validtj))) & (shotcoord(i)<=max(fbcoord(j,validtj))) )

	       t2=interp1(fbcoord(j,validtj),fbtime(j,validtj),shotcoord(i),'linear');
	      end
	    end
	    diffmat(i,j) = t2-t1;
	  end
	end
% Reciprocal time difference for a specified shot pair
else
	i=rtpair1
	j=rtpair2
	t1 = NaN;
	t2 = NaN;
        validti = find(~isnan(fbtime(i,:)));
        validtj = find(~isnan(fbtime(j,:)));
	if (length(validti)>0 & length(validtj)>0)
 	  if( (shotcoord(j)>=min(fbcoord(i,validti))) & (shotcoord(j)<=max(fbcoord(i,validti))) )
	      t1=interp1(fbcoord(i,validti),fbtime(i,validti),shotcoord(j),'linear');	
	  end
	  if( shotcoord(i) >= min(fbcoord(j,validtj)) & shotcoord(i) <= max(fbcoord(j,validtj)) )
	      t2=interp1(fbcoord(j,validtj),fbtime(j,validtj),shotcoord(i),'linear');
 	  end
	end
	diffmat(i,j) = t2-t1;
end


absdiffmat=abs(diffmat);
[s1,s2]=find(absdiffmat>mint);  %reciprocal time bigger than a minimum time(ms)
m=size(s1);

% We need to save the current figure, and restore it afterwards, so that
% refdata (which stores data under the MAIN figure) will work.
f = gcf;

% Display the reciprocal time difference for the possible shot pairs
if( rtrange==0)
	figure('menubar','none');
	plot(absdiffmat,'*');
	xlabel('shot number');
	ylabel('Reciprocal traveltime difference (ms)');
	title('Reciprocal time difference for all possible shot pairs ')
% Display of the shot pairs over a reciprocal time difference limit
	figure('menubar','none');
	plot(s2,s1,'*');
	xlabel('shot number');
	ylabel('shot number');
	titlestr = sprintf('Shot pair(s) with over %d ms of reciprocal time difference ', mint);
	title(titlestr);
else
	mint
	t2-t1
end

figure(f); set(gcf,'menubar','none');