'src.dat' 'rec.dat' 'rays.out' 'end.out' / / ' ' 'vel.dat' ' ' 'tt.out' 'err.out' / ------------------------------------------------------------------------ The above sample data for the 'NET' program specify a 2-D network ray tracing in a 1-D velocity gradient model by P.Podvin and I.Lecomte (1991), Geophys.J.int., 105, 271-284, Fig.13c. Note: Since there are no structural interfaces in this model, the input file 'ICB' with the indices of geological blocks is not specified.