Rough Seabed Reverberation

This example computes the reverberation in a 200 Hz band around 500 Hz from a rough stratified seabed in shallow water. The source is assumed to be a line source (option P). The field is computed for vertical arrays at range 0 m (monostatic) and 500 m (bistatic). The data file wg-rhs.dat for computing the mean field using automatic sampling is:

Line source. Mean field. Goff. auto.
P B N s g O 
500 0
4
0          0      0     0     0     0      0
0       1500      0     0     0     1      0 
128.    1470   0000.00  0.01  0.00  1.650  0.5  0
228.00  2300   0000.00  0.50  0.00  2.650  0.0000  	

100.
52. 127. 51

1200 -1200
-1 1 1 0
2048 400 600 0.0004 0 .5 2

  

Figure 5: Mean field envelope in shallow water example

Figure5 shows the depth-stacked plots of the the mean field envelopes for the monostatic receiver array, generated using PP.

The associated input file wg-scat.dat for OASSP is:

Seabed scat. Line source. Goff-J. auto.
P B N O s g  
500 0
4
  0.       0      0     0     0     1      0       0
  0.    1500      0     0     0     1      0       0
128.    1470   0000.00  0.01  0.00  1.650  -0.5   5.0 
228.00  2300   0000.00  0.50  0.00  2.650  0.0000 0.0 	

128.
77. 127. 51

1200 -1200
2048 1 2048 0
2048 400 600 0.0004 0 0.5 2

  

Figure 6: Reverberant field envelope in shallow water seabed roughness scattering example

The main difference is that the wavenumber sampling was chosen manually here, and a finite roughness correlation length was specified. The field envelopes for the monostatic vertical array are shown in Fig.6.