Variable boundaries

Bellhop is not only able to handle a variable bottom, it can also deal simultaneously with a variable surface and bottom. Let us illustrate this by copying the seamount.bty file as varbounds.bty; further, we create a varbounds.ati file containing the coordinates of a wavy surface, which looks like this:

'L'
101
   0.0000000e+00   1.0000000e+02
   1.0100000e+00   1.3090170e+02
   2.0200000e+00   1.5877853e+02
   3.0300000e+00   1.8090170e+02
   4.0400000e+00   1.9510565e+02
   5.0500000e+00   2.0000000e+02
   6.0600000e+00   1.9510565e+02
   7.0700000e+00   1.8090170e+02
   8.0800000e+00   1.5877853e+02
         .               .
         .               .
         .               .
   9.6960000e+01   4.8943484e+00
   9.7970000e+01   1.9098301e+01
   9.8980000e+01   4.1221475e+01
   9.9990000e+01   6.9098301e+01
   1.0100000e+02   1.0000000e+02

Then, seamount.env is copied as varbounds.env, and modified to look like follows:

'Munk profile/Variable boundaries' 
50.0			
1			
'SVW *'			
51  0.0  5000.0	
    0.0  1548.52  /
  200.0  1530.29  /
  250.0  1526.69  /
  400.0  1517.78  /
  600.0  1509.49  /
  800.0  1504.30  /
 1000.0  1501.38  /
 1200.0  1500.14  /
 1400.0  1500.12  /
 1600.0  1501.02  /
 1800.0  1502.57  /
 2000.0  1504.62  /
 2200.0  1507.02  /
 2400.0  1509.69  /
 2600.0  1512.55  /
 2800.0  1515.56  /
 3000.0  1518.67  /
 3200.0  1521.85  /
 3400.0  1525.10  /
 3600.0  1528.38  /
 3800.0  1531.70  /
 4000.0  1535.04  /
 4200.0  1538.39  /
 4400.0  1541.76  /
 4600.0  1545.14  /
 4800.0  1548.52  /
 5000.0  1551.91  /
'A*'  0.0
 5000.0  1600.00 0.0 1.8 .0 /
1
  1000.0 /		
 1
   5000.0 /	
 1
    101.0 /	
'R'	  		
71
 -14.0 14.0  /       
100.0  5500.0  102.0

Running Bellhop with this input file we can get Fig.6.

Figure 6: Rays calculated by Bellhop in a deep water waveguide with a wavy surface and a Gaussian seamount.