TL for low freq case
N T J
10 10 1 0                          src freq
3                             nb of layers
  0    0 0 0    0     0   0   #1 (upper half space)
  0 1500 0 0 -888.888 1.0 0   #2
+100.0
100 1800 0 0    0     1.8 0   #3
50                            src depth
50 50 1 1                     rcv depths
1300 1e8                      cmin cmax
-1 1 1 0                      k integration parameters
0 20 20 1		      range param.
30 70 10 5		      TL param.