Altimetry or Bathymetry File


The format is the same for top altimetry or bottom bathymetry. Only BELLHOP uses these files.

Syntax:

TYPE
NPOINTS

R(1)       Z(1)

R(2)       Z(2)
 
.
 
.
 .
R
(NPOINTS)  Z(NPOINTS)

Description:

TYPE
'L' for piecewise linear
'C' for curvilinear

NPOINTS: Number of r-z points to follow.
R():     Range (km)
Z():     Depth (m).

Example:

'L'
5
  0  3000
 10  3000
 20   500
 30   3000
100   3000


Generally the piecewise linear option should be selected. However, if the boundaries are sampled on a very fine scale (a few wavelengths) then the curvilinear option produces a smoother fit. That in turn improves the results obtained with geometric ray tracing. The curvilinear option was implemented to treat fine scale scattering effects.

Note that depths, z, are positive downward, following a convention used throughout the models. This is a bit counter-intuitive for altimetry; however, a different convention for that would also have been counter-intuitive for others.