Range-Dependent SSP File


If you select option 'Q' (quadrilateral elements) for the SSP interpolation, BELLHOP will read a range-dependent SSP from an SSPFIL. The format of the SSPFIL is as follows:

Range-dependent SSP

Syntax:

NPROFILES
RPROF( 1 )  RPROF( 2 ) ...  RPROF( NPROFILES )
C( 1, 1 )   C( 1, 2 )  ...  C( 1, NPROFILES )
C( 2, 1 )   C( 2, 2 )  ...  C( 2, NPROFILES )
 
.
 
.
 .
C( NZ, 1 )  C( NZ, 2 )     ...  C( NZ, NPROFILES )

Description:

NPROFILES:   Number of profiles.
NZ:          Number of depth points where SSP is sampled
RPROF():     Range of each profile in km.
C():         Sound speed. c( iz, iprof ) is the sound speed at the depth point, iz, in profile, iprof.

Example:


8
0.0     12.5     25.0    37.5    50.0    75.0    100.0   125.0
1536    1536     1536    1536    1536    1536    1536    1536
1506    1508.75  1511.5  1514.25 1517    1520    1524    1528
1503    1503     1503    1502.75 1502.5  1502    1502    1502
1508    1507     1506    1505    1504    1503    1501.5  1500
1508    1506.6   1505    1503.75 1502.5  1500.5  1499    1497
1497    1497     1497    1497    1497    1497    1497    1497
1500    1500     1500    1500    1500    1500    1500    1500
1512    1512     1512    1512    1512    1512    1512    1512
1528    1528     1528    1528    1528    1528    1528    1528
1545    1545     1545    1545    1545    1545    1545    1545


Note: The main BELLHOP envfil must contain a dummy SSP with NZ depth points. Those depths points are used to interpret the depths in the above SSP matrix.

The vector of profile ranges must increase strictly monotonically.

See the example in at/tests/Gulf. Note that the SSP is NOT extrapolated outside the domain of ranges. If you trace rays to ranges outside that domain, you will get an error message. That limit for tracing rays is controlled by rBox. Keep in mind also that BELLHOP will trace rays to negative 'ranges' if the launch angles go to the left or if boundary interactions cause the rays to reverse.