A Gaussian seamountain (variable bottom)

Let us illustrate ray calculations with Bellhop with a non-flat bottom. We idealize a seamount using a Gaussian function and define it in a file called seamount.bty, which looks like this:

'L'
101
   0.0000000e+00   4.9971624e+03
   1.0100000e+00   4.9963474e+03
   2.0200000e+00   4.9953223e+03
   3.0300000e+00   4.9940400e+03
   4.0400000e+00   4.9924447e+03
   5.0500000e+00   4.9904711e+03
         .               .
         .               .
         .               .
   9.6960000e+01   4.9924447e+03
   9.7970000e+01   4.9940400e+03
   9.8980000e+01   4.9953223e+03
   9.9990000e+01   4.9963474e+03
   1.0100000e+02   4.9971624e+03

Next we make a copy of flatwav.env called seamount.env, and modify it like shown below:

'Munk profile/Seamount' 
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

After running Bellhop we can plot the rays (shown in Fig.5) using plotrays.m. As in the previous case eigenray calculations or coherent transmission loss can be obtained by replacing OPTIONS3(1) = 'R' with OPTIONS3(1) = 'E' and OPTIONS3(1) = 'C', respectively. However, keep in mind that the array block should be written accordingly for every of those options.

Figure 5: Rays calculated by Bellhop in a deep water waveguide with a Gaussian seamount.