function [t3,jd3]=merge(t1,jd1,t2,jd2);
% function [t3,jd3]=merge(t1,jd1,t2,jd2);
% merge two time series together, using the time base of
% former. 
n1=length(jd1);
n2=length(jd2);
dt=jd1(2)-jd1(1);
nt=(last(jd2)-jd1(1))/dt;
j=0:nt;
jd3=jd1(1)+j*dt;
t3=interp(jd2,t2,jd3);
t3(1:n1,:)=t1;
